4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
35 #include <stdarg.h> /* Needed for the definition of va_list */
38 ** Make sure we can call this stuff from C++.
46 ** Facilitate override of interface linkage and calling conventions.
47 ** Be aware that these macros may not be used within this particular
48 ** translation of the amalgamation and its associated header file.
50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51 ** compiler that the target identifier should have external linkage.
53 ** The SQLITE_CDECL macro is used to set the calling convention for
54 ** public functions that accept a variable number of arguments.
56 ** The SQLITE_APICALL macro is used to set the calling convention for
57 ** public functions that accept a fixed number of arguments.
59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
61 ** The SQLITE_CALLBACK macro is used to set the calling convention for
64 ** The SQLITE_SYSAPI macro is used to set the calling convention for
65 ** functions provided by the operating system.
67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68 ** SQLITE_SYSAPI macros are used only when building for environments
69 ** that require non-default calling conventions.
72 # define SQLITE_EXTERN extern
80 #ifndef SQLITE_APICALL
81 # define SQLITE_APICALL
83 #ifndef SQLITE_STDCALL
84 # define SQLITE_STDCALL SQLITE_APICALL
86 #ifndef SQLITE_CALLBACK
87 # define SQLITE_CALLBACK
90 # define SQLITE_SYSAPI
94 ** These no-op macros are used in front of interfaces to mark those
95 ** interfaces as either deprecated or experimental. New applications
96 ** should not use deprecated interfaces - they are supported for backwards
97 ** compatibility only. Application writers should be aware that
98 ** experimental interfaces are subject to change in point releases.
100 ** These macros used to resolve to various kinds of compiler magic that
101 ** would generate warning messages when they were used. But that
102 ** compiler magic ended up generating such a flurry of bug reports
103 ** that we have taken it all out and gone back to using simple
106 #define SQLITE_DEPRECATED
107 #define SQLITE_EXPERIMENTAL
110 ** Ensure these symbols were not defined by some previous header file.
112 #ifdef SQLITE_VERSION
113 # undef SQLITE_VERSION
115 #ifdef SQLITE_VERSION_NUMBER
116 # undef SQLITE_VERSION_NUMBER
120 ** CAPI3REF: Compile-Time Library Version Numbers
122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123 ** evaluates to a string literal that is the SQLite version in the
124 ** format "X.Y.Z" where X is the major version number (always 3 for
125 ** SQLite3) and Y is the minor version number and Z is the release number.)^
126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128 ** numbers used in [SQLITE_VERSION].)^
129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130 ** be larger than the release from which it is derived. Either Y will
131 ** be held constant and Z will be incremented or else Y will be incremented
132 ** and Z will be reset to zero.
134 ** Since [version 3.6.18] ([dateof:3.6.18]),
135 ** SQLite source code has been stored in the
136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138 ** a string which identifies a particular check-in of SQLite
139 ** within its configuration management system. ^The SQLITE_SOURCE_ID
140 ** string contains the date and time of the check-in (UTC) and a SHA1
141 ** or SHA3-256 hash of the entire source tree. If the source code has
142 ** been edited in any way since it was last checked in, then the last
143 ** four hexadecimal digits of the hash may be modified.
145 ** See also: [sqlite3_libversion()],
146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147 ** [sqlite_version()] and [sqlite_source_id()].
149 #define SQLITE_VERSION "3.37.0"
150 #define SQLITE_VERSION_NUMBER 3037000
151 #define SQLITE_SOURCE_ID "2021-11-27 14:13:22 bd41822c7424d393a30e92ff6cb254d25c26769889c1499a18a0b9339f5d6c8a"
154 ** CAPI3REF: Run-Time Library Version Numbers
155 ** KEYWORDS: sqlite3_version sqlite3_sourceid
157 ** These interfaces provide the same information as the [SQLITE_VERSION],
158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159 ** but are associated with the library instead of the header file. ^(Cautious
160 ** programmers might include assert() statements in their application to
161 ** verify that values returned by these interfaces match the macros in
162 ** the header, and thus ensure that the application is
163 ** compiled with matching library and header files.
166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169 ** </pre></blockquote>)^
171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172 ** macro. ^The sqlite3_libversion() function returns a pointer to the
173 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
174 ** function is provided for use in DLLs since DLL users usually do not have
175 ** direct access to string constants within the DLL. ^The
176 ** sqlite3_libversion_number() function returns an integer equal to
177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178 ** a pointer to a string constant whose value is the same as the
179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180 ** using an edited copy of [the amalgamation], then the last four characters
181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
183 ** See also: [sqlite_version()] and [sqlite_source_id()].
185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186 SQLITE_API const char *sqlite3_libversion(void);
187 SQLITE_API const char *sqlite3_sourceid(void);
188 SQLITE_API int sqlite3_libversion_number(void);
191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
193 ** ^The sqlite3_compileoption_used() function returns 0 or 1
194 ** indicating whether the specified option was defined at
195 ** compile time. ^The SQLITE_ prefix may be omitted from the
196 ** option name passed to sqlite3_compileoption_used().
198 ** ^The sqlite3_compileoption_get() function allows iterating
199 ** over the list of options that were defined at compile time by
200 ** returning the N-th compile time option string. ^If N is out of range,
201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202 ** prefix is omitted from any strings returned by
203 ** sqlite3_compileoption_get().
205 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
206 ** and sqlite3_compileoption_get() may be omitted by specifying the
207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
209 ** See also: SQL functions [sqlite_compileoption_used()] and
210 ** [sqlite_compileoption_get()] and the [compile_options pragma].
212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214 SQLITE_API const char *sqlite3_compileoption_get(int N);
216 # define sqlite3_compileoption_used(X) 0
217 # define sqlite3_compileoption_get(X) ((void*)0)
221 ** CAPI3REF: Test To See If The Library Is Threadsafe
223 ** ^The sqlite3_threadsafe() function returns zero if and only if
224 ** SQLite was compiled with mutexing code omitted due to the
225 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
227 ** SQLite can be compiled with or without mutexes. When
228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229 ** are enabled and SQLite is threadsafe. When the
230 ** [SQLITE_THREADSAFE] macro is 0,
231 ** the mutexes are omitted. Without the mutexes, it is not safe
232 ** to use SQLite concurrently from more than one thread.
234 ** Enabling mutexes incurs a measurable performance penalty.
235 ** So if speed is of utmost importance, it makes sense to disable
236 ** the mutexes. But for maximum safety, mutexes should be enabled.
237 ** ^The default behavior is for mutexes to be enabled.
239 ** This interface can be used by an application to make sure that the
240 ** version of SQLite that it is linking against was compiled with
241 ** the desired setting of the [SQLITE_THREADSAFE] macro.
243 ** This interface only reports on the compile-time mutex setting
244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246 ** can be fully or partially disabled using a call to [sqlite3_config()]
247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249 ** sqlite3_threadsafe() function shows only the compile-time setting of
250 ** thread safety, not any run-time changes to that setting made by
251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252 ** is unchanged by calls to sqlite3_config().)^
254 ** See the [threading mode] documentation for additional information.
256 SQLITE_API int sqlite3_threadsafe(void);
259 ** CAPI3REF: Database Connection Handle
260 ** KEYWORDS: {database connection} {database connections}
262 ** Each open SQLite database is represented by a pointer to an instance of
263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266 ** and [sqlite3_close_v2()] are its destructors. There are many other
267 ** interfaces (such as
268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
272 typedef struct sqlite3 sqlite3;
275 ** CAPI3REF: 64-Bit Integer Types
276 ** KEYWORDS: sqlite_int64 sqlite_uint64
278 ** Because there is no cross-platform way to specify 64-bit integer types
279 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283 ** compatibility only.
285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
288 ** between 0 and +18446744073709551615 inclusive.
290 #ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292 # ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
297 #elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
304 typedef sqlite_int64 sqlite3_int64;
305 typedef sqlite_uint64 sqlite3_uint64;
308 ** If compiling for a processor that lacks floating point support,
309 ** substitute integer for floating-point.
311 #ifdef SQLITE_OMIT_FLOATING_POINT
312 # define double sqlite3_int64
316 ** CAPI3REF: Closing A Database Connection
317 ** DESTRUCTOR: sqlite3
319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320 ** for the [sqlite3] object.
321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322 ** the [sqlite3] object is successfully destroyed and all associated
323 ** resources are deallocated.
325 ** Ideally, applications should [sqlite3_finalize | finalize] all
326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328 ** with the [sqlite3] object prior to attempting to close the object.
329 ** ^If the database connection is associated with unfinalized prepared
330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331 ** sqlite3_close() will leave the database connection open and return
332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335 ** connection immediately, it marks the database connection as an unusable
336 ** "zombie" and makes arrangements to automatically deallocate the database
337 ** connection after all prepared statements are finalized, all BLOB handles
338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
339 ** is intended for use with host languages that are garbage collected, and
340 ** where the order in which destructors are called is arbitrary.
342 ** ^If an [sqlite3] object is destroyed while a transaction is open,
343 ** the transaction is automatically rolled back.
345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346 ** must be either a NULL
347 ** pointer or an [sqlite3] object pointer obtained
348 ** from [sqlite3_open()], [sqlite3_open16()], or
349 ** [sqlite3_open_v2()], and not previously closed.
350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351 ** argument is a harmless no-op.
353 SQLITE_API int sqlite3_close(sqlite3*);
354 SQLITE_API int sqlite3_close_v2(sqlite3*);
357 ** The type for a callback function.
358 ** This is legacy and deprecated. It is included for historical
359 ** compatibility and is not documented.
361 typedef int (*sqlite3_callback)(void*,int,char**, char**);
364 ** CAPI3REF: One-Step Query Execution Interface
367 ** The sqlite3_exec() interface is a convenience wrapper around
368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369 ** that allows an application to run multiple statements of SQL
370 ** without having to use a lot of C code.
372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373 ** semicolon-separate SQL statements passed into its 2nd argument,
374 ** in the context of the [database connection] passed in as its 1st
375 ** argument. ^If the callback function of the 3rd argument to
376 ** sqlite3_exec() is not NULL, then it is invoked for each result row
377 ** coming out of the evaluated SQL statements. ^The 4th argument to
378 ** sqlite3_exec() is relayed through to the 1st argument of each
379 ** callback invocation. ^If the callback pointer to sqlite3_exec()
380 ** is NULL, then no callback is ever invoked and result rows are
383 ** ^If an error occurs while evaluating the SQL statements passed into
384 ** sqlite3_exec(), then execution of the current statement stops and
385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386 ** is not NULL then any error message is written into memory obtained
387 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
388 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
389 ** on error message strings returned through the 5th parameter of
390 ** sqlite3_exec() after the error message string is no longer needed.
391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393 ** NULL before returning.
395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396 ** routine returns SQLITE_ABORT without invoking the callback again and
397 ** without running any subsequent SQL statements.
399 ** ^The 2nd argument to the sqlite3_exec() callback function is the
400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401 ** callback is an array of pointers to strings obtained as if from
402 ** [sqlite3_column_text()], one for each column. ^If an element of a
403 ** result row is NULL then the corresponding string pointer for the
404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405 ** sqlite3_exec() callback is an array of pointers to strings where each
406 ** entry represents the name of corresponding result column as obtained
407 ** from [sqlite3_column_name()].
409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410 ** to an empty string, or a pointer that contains only whitespace and/or
411 ** SQL comments, then no SQL statements are evaluated and the database
417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418 ** is a valid and open [database connection].
419 ** <li> The application must not close the [database connection] specified by
420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421 ** <li> The application must not modify the SQL statement text passed into
422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
425 SQLITE_API int sqlite3_exec(
426 sqlite3*, /* An open database */
427 const char *sql, /* SQL to be evaluated */
428 int (*callback)(void*,int,char**,char**), /* Callback function */
429 void *, /* 1st argument to callback */
430 char **errmsg /* Error msg written here */
434 ** CAPI3REF: Result Codes
435 ** KEYWORDS: {result code definitions}
437 ** Many SQLite functions return an integer result code from the set shown
438 ** here in order to indicate success or failure.
440 ** New error codes may be added in future versions of SQLite.
442 ** See also: [extended result code definitions]
444 #define SQLITE_OK 0 /* Successful result */
445 /* beginning-of-error-codes */
446 #define SQLITE_ERROR 1 /* Generic error */
447 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448 #define SQLITE_PERM 3 /* Access permission denied */
449 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
450 #define SQLITE_BUSY 5 /* The database file is locked */
451 #define SQLITE_LOCKED 6 /* A table in the database is locked */
452 #define SQLITE_NOMEM 7 /* A malloc() failed */
453 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458 #define SQLITE_FULL 13 /* Insertion failed because database is full */
459 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461 #define SQLITE_EMPTY 16 /* Internal use only */
462 #define SQLITE_SCHEMA 17 /* The database schema changed */
463 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465 #define SQLITE_MISMATCH 20 /* Data type mismatch */
466 #define SQLITE_MISUSE 21 /* Library used incorrectly */
467 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468 #define SQLITE_AUTH 23 /* Authorization denied */
469 #define SQLITE_FORMAT 24 /* Not used */
470 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
472 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476 /* end-of-error-codes */
479 ** CAPI3REF: Extended Result Codes
480 ** KEYWORDS: {extended result code definitions}
482 ** In its default configuration, SQLite API routines return one of 30 integer
483 ** [result codes]. However, experience has shown that many of
484 ** these result codes are too coarse-grained. They do not provide as
485 ** much information about problems as programmers might like. In an effort to
486 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487 ** and later) include
488 ** support for additional result codes that provide more detailed information
489 ** about errors. These [extended result codes] are enabled or disabled
490 ** on a per database connection basis using the
491 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
492 ** the most recent error can be obtained using
493 ** [sqlite3_extended_errcode()].
495 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
532 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
533 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
534 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
535 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
536 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
537 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
538 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
539 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
540 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
541 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
542 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
543 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
544 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
545 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
546 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
547 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
548 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
549 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
550 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
551 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
552 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
553 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
554 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
555 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
556 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
557 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
558 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
559 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
560 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
561 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
562 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
563 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
564 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
565 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
566 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
567 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
568 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
569 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8))
572 ** CAPI3REF: Flags For File Open Operations
574 ** These bit values are intended for use in the
575 ** 3rd parameter to the [sqlite3_open_v2()] interface and
576 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
578 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
579 ** used as the third argument to the [sqlite3_open_v2()] interface.
580 ** The other flags have historically been ignored by sqlite3_open_v2(),
581 ** though future versions of SQLite might change so that an error is
582 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
583 ** Applications should not depend on the historical behavior.
585 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
586 ** [sqlite3_open_v2()] does *not* cause the underlying database file
587 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
588 ** [sqlite3_open_v2()] has historically be a no-op and might become an
589 ** error in future versions of SQLite.
591 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
592 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
593 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
594 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
595 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
596 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
597 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
598 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
599 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
600 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
601 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
602 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
603 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
604 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
605 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
606 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
607 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
608 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
609 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
610 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
611 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
612 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
614 /* Reserved: 0x00F00000 */
615 /* Legacy compatibility: */
616 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
620 ** CAPI3REF: Device Characteristics
622 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
623 ** object returns an integer which is a vector of these
624 ** bit values expressing I/O characteristics of the mass storage
625 ** device that holds the file that the [sqlite3_io_methods]
628 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
629 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
630 ** mean that writes of blocks that are nnn bytes in size and
631 ** are aligned to an address which is an integer multiple of
632 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
633 ** that when data is appended to a file, the data is appended
634 ** first then the size of the file is extended, never the other
635 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
636 ** information is written to disk in the same order as calls
637 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
638 ** after reboot following a crash or power loss, the only bytes in a
639 ** file that were written at the application level might have changed
640 ** and that adjacent bytes, even bytes within the same sector are
641 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
642 ** flag indicates that a file cannot be deleted when open. The
643 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
644 ** read-only media and cannot be changed even by processes with
645 ** elevated privileges.
647 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
648 ** filesystem supports doing multiple write operations atomically when those
649 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
650 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
652 #define SQLITE_IOCAP_ATOMIC 0x00000001
653 #define SQLITE_IOCAP_ATOMIC512 0x00000002
654 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
655 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
656 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
657 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
658 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
659 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
660 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
661 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
662 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
663 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
664 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
665 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
666 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
669 ** CAPI3REF: File Locking Levels
671 ** SQLite uses one of these integer values as the second
672 ** argument to calls it makes to the xLock() and xUnlock() methods
673 ** of an [sqlite3_io_methods] object.
675 #define SQLITE_LOCK_NONE 0
676 #define SQLITE_LOCK_SHARED 1
677 #define SQLITE_LOCK_RESERVED 2
678 #define SQLITE_LOCK_PENDING 3
679 #define SQLITE_LOCK_EXCLUSIVE 4
682 ** CAPI3REF: Synchronization Type Flags
684 ** When SQLite invokes the xSync() method of an
685 ** [sqlite3_io_methods] object it uses a combination of
686 ** these integer values as the second argument.
688 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
689 ** sync operation only needs to flush data to mass storage. Inode
690 ** information need not be flushed. If the lower four bits of the flag
691 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
692 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
693 ** to use Mac OS X style fullsync instead of fsync().
695 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
696 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
697 ** settings. The [synchronous pragma] determines when calls to the
698 ** xSync VFS method occur and applies uniformly across all platforms.
699 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
700 ** energetic or rigorous or forceful the sync operations are and
701 ** only make a difference on Mac OSX for the default SQLite code.
702 ** (Third-party VFS implementations might also make the distinction
703 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
704 ** operating systems natively supported by SQLite, only Mac OSX
705 ** cares about the difference.)
707 #define SQLITE_SYNC_NORMAL 0x00002
708 #define SQLITE_SYNC_FULL 0x00003
709 #define SQLITE_SYNC_DATAONLY 0x00010
712 ** CAPI3REF: OS Interface Open File Handle
714 ** An [sqlite3_file] object represents an open file in the
715 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
716 ** implementations will
717 ** want to subclass this object by appending additional fields
718 ** for their own use. The pMethods entry is a pointer to an
719 ** [sqlite3_io_methods] object that defines methods for performing
720 ** I/O operations on the open file.
722 typedef struct sqlite3_file sqlite3_file;
723 struct sqlite3_file {
724 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
728 ** CAPI3REF: OS Interface File Virtual Methods Object
730 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
731 ** [sqlite3_file] object (or, more commonly, a subclass of the
732 ** [sqlite3_file] object) with a pointer to an instance of this object.
733 ** This object defines the methods used to perform various operations
734 ** against the open file represented by the [sqlite3_file] object.
736 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
737 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
738 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
739 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
740 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
743 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
744 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
745 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
746 ** flag may be ORed in to indicate that only the data of the file
747 ** and not its inode needs to be synced.
749 ** The integer values to xLock() and xUnlock() are one of
751 ** <li> [SQLITE_LOCK_NONE],
752 ** <li> [SQLITE_LOCK_SHARED],
753 ** <li> [SQLITE_LOCK_RESERVED],
754 ** <li> [SQLITE_LOCK_PENDING], or
755 ** <li> [SQLITE_LOCK_EXCLUSIVE].
757 ** xLock() increases the lock. xUnlock() decreases the lock.
758 ** The xCheckReservedLock() method checks whether any database connection,
759 ** either in this process or in some other process, is holding a RESERVED,
760 ** PENDING, or EXCLUSIVE lock on the file. It returns true
761 ** if such a lock exists and false otherwise.
763 ** The xFileControl() method is a generic interface that allows custom
764 ** VFS implementations to directly control an open file using the
765 ** [sqlite3_file_control()] interface. The second "op" argument is an
766 ** integer opcode. The third argument is a generic pointer intended to
767 ** point to a structure that may contain arguments or space in which to
768 ** write return values. Potential uses for xFileControl() might be
769 ** functions to enable blocking locks with timeouts, to change the
770 ** locking strategy (for example to use dot-file locks), to inquire
771 ** about the status of a lock, or to break stale locks. The SQLite
772 ** core reserves all opcodes less than 100 for its own use.
773 ** A [file control opcodes | list of opcodes] less than 100 is available.
774 ** Applications that define a custom xFileControl method should use opcodes
775 ** greater than 100 to avoid conflicts. VFS implementations should
776 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
779 ** The xSectorSize() method returns the sector size of the
780 ** device that underlies the file. The sector size is the
781 ** minimum write that can be performed without disturbing
782 ** other bytes in the file. The xDeviceCharacteristics()
783 ** method returns a bit vector describing behaviors of the
784 ** underlying device:
787 ** <li> [SQLITE_IOCAP_ATOMIC]
788 ** <li> [SQLITE_IOCAP_ATOMIC512]
789 ** <li> [SQLITE_IOCAP_ATOMIC1K]
790 ** <li> [SQLITE_IOCAP_ATOMIC2K]
791 ** <li> [SQLITE_IOCAP_ATOMIC4K]
792 ** <li> [SQLITE_IOCAP_ATOMIC8K]
793 ** <li> [SQLITE_IOCAP_ATOMIC16K]
794 ** <li> [SQLITE_IOCAP_ATOMIC32K]
795 ** <li> [SQLITE_IOCAP_ATOMIC64K]
796 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
797 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
798 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
799 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
800 ** <li> [SQLITE_IOCAP_IMMUTABLE]
801 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
804 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
805 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
806 ** mean that writes of blocks that are nnn bytes in size and
807 ** are aligned to an address which is an integer multiple of
808 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
809 ** that when data is appended to a file, the data is appended
810 ** first then the size of the file is extended, never the other
811 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
812 ** information is written to disk in the same order as calls
815 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
816 ** in the unread portions of the buffer with zeros. A VFS that
817 ** fails to zero-fill short reads might seem to work. However,
818 ** failure to zero-fill short reads will eventually lead to
819 ** database corruption.
821 typedef struct sqlite3_io_methods sqlite3_io_methods;
822 struct sqlite3_io_methods {
824 int (*xClose)(sqlite3_file*);
825 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
826 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
827 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
828 int (*xSync)(sqlite3_file*, int flags);
829 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
830 int (*xLock)(sqlite3_file*, int);
831 int (*xUnlock)(sqlite3_file*, int);
832 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
833 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
834 int (*xSectorSize)(sqlite3_file*);
835 int (*xDeviceCharacteristics)(sqlite3_file*);
836 /* Methods above are valid for version 1 */
837 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
838 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
839 void (*xShmBarrier)(sqlite3_file*);
840 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
841 /* Methods above are valid for version 2 */
842 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
843 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
844 /* Methods above are valid for version 3 */
845 /* Additional methods may be added in future releases */
849 ** CAPI3REF: Standard File Control Opcodes
850 ** KEYWORDS: {file control opcodes} {file control opcode}
852 ** These integer constants are opcodes for the xFileControl method
853 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
857 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
858 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
859 ** opcode causes the xFileControl method to write the current state of
860 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
861 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
862 ** into an integer that the pArg argument points to. This capability
863 ** is used during testing and is only available when the SQLITE_TEST
864 ** compile-time option is used.
866 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
867 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
868 ** layer a hint of how large the database file will grow to be during the
869 ** current transaction. This hint is not guaranteed to be accurate but it
870 ** is often close. The underlying VFS might choose to preallocate database
871 ** file space based on this hint in order to help writes to the database
874 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
875 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
876 ** implements [sqlite3_deserialize()] to set an upper bound on the size
877 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
878 ** If the integer pointed to is negative, then it is filled in with the
879 ** current limit. Otherwise the limit is set to the larger of the value
880 ** of the integer pointed to and the current database size. The integer
881 ** pointed to is set to the new limit.
883 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
884 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
885 ** extends and truncates the database file in chunks of a size specified
886 ** by the user. The fourth argument to [sqlite3_file_control()] should
887 ** point to an integer (type int) containing the new chunk-size to use
888 ** for the nominated database. Allocating database file space in large
889 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
890 ** improve performance on some systems.
892 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
893 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
894 ** to the [sqlite3_file] object associated with a particular database
895 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
897 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
898 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
899 ** to the [sqlite3_file] object associated with the journal file (either
900 ** the [rollback journal] or the [write-ahead log]) for a particular database
901 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
903 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
906 ** <li>[[SQLITE_FCNTL_SYNC]]
907 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
908 ** sent to the VFS immediately before the xSync method is invoked on a
909 ** database file descriptor. Or, if the xSync method is not invoked
910 ** because the user has configured SQLite with
911 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
912 ** of the xSync method. In most cases, the pointer argument passed with
913 ** this file-control is NULL. However, if the database file is being synced
914 ** as part of a multi-database commit, the argument points to a nul-terminated
915 ** string containing the transactions super-journal file name. VFSes that
916 ** do not need this signal should silently ignore this opcode. Applications
917 ** should not call [sqlite3_file_control()] with this opcode as doing so may
918 ** disrupt the operation of the specialized VFSes that do require it.
920 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
921 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
922 ** and sent to the VFS after a transaction has been committed immediately
923 ** but before the database is unlocked. VFSes that do not need this signal
924 ** should silently ignore this opcode. Applications should not call
925 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
926 ** operation of the specialized VFSes that do require it.
928 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
929 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
930 ** retry counts and intervals for certain disk I/O operations for the
931 ** windows [VFS] in order to provide robustness in the presence of
932 ** anti-virus programs. By default, the windows VFS will retry file read,
933 ** file write, and file delete operations up to 10 times, with a delay
934 ** of 25 milliseconds before the first retry and with the delay increasing
935 ** by an additional 25 milliseconds with each subsequent retry. This
936 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
937 ** to be adjusted. The values are changed for all database connections
938 ** within the same process. The argument is a pointer to an array of two
939 ** integers where the first integer is the new retry count and the second
940 ** integer is the delay. If either integer is negative, then the setting
941 ** is not changed but instead the prior value of that setting is written
942 ** into the array entry, allowing the current retry settings to be
943 ** interrogated. The zDbName parameter is ignored.
945 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
946 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
947 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
948 ** write ahead log ([WAL file]) and shared memory
949 ** files used for transaction control
950 ** are automatically deleted when the latest connection to the database
951 ** closes. Setting persistent WAL mode causes those files to persist after
952 ** close. Persisting the files is useful when other processes that do not
953 ** have write permission on the directory containing the database file want
954 ** to read the database file, as the WAL and shared memory files must exist
955 ** in order for the database to be readable. The fourth parameter to
956 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
957 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
958 ** WAL mode. If the integer is -1, then it is overwritten with the current
959 ** WAL persistence setting.
961 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
962 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
963 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
964 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
965 ** xDeviceCharacteristics methods. The fourth parameter to
966 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
967 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
968 ** mode. If the integer is -1, then it is overwritten with the current
969 ** zero-damage mode setting.
971 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
972 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
973 ** a write transaction to indicate that, unless it is rolled back for some
974 ** reason, the entire database file will be overwritten by the current
975 ** transaction. This is used by VACUUM operations.
977 ** <li>[[SQLITE_FCNTL_VFSNAME]]
978 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
979 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
980 ** final bottom-level VFS are written into memory obtained from
981 ** [sqlite3_malloc()] and the result is stored in the char* variable
982 ** that the fourth parameter of [sqlite3_file_control()] points to.
983 ** The caller is responsible for freeing the memory when done. As with
984 ** all file-control actions, there is no guarantee that this will actually
985 ** do anything. Callers should initialize the char* variable to a NULL
986 ** pointer in case this file-control is not implemented. This file-control
987 ** is intended for diagnostic use only.
989 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
990 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
991 ** [VFSes] currently in use. ^(The argument X in
992 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
993 ** of type "[sqlite3_vfs] **". This opcodes will set *X
994 ** to a pointer to the top-level VFS.)^
995 ** ^When there are multiple VFS shims in the stack, this opcode finds the
996 ** upper-most shim only.
998 ** <li>[[SQLITE_FCNTL_PRAGMA]]
999 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1000 ** file control is sent to the open [sqlite3_file] object corresponding
1001 ** to the database file to which the pragma statement refers. ^The argument
1002 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1003 ** pointers to strings (char**) in which the second element of the array
1004 ** is the name of the pragma and the third element is the argument to the
1005 ** pragma or NULL if the pragma has no argument. ^The handler for an
1006 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1007 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1008 ** or the equivalent and that string will become the result of the pragma or
1009 ** the error message if the pragma fails. ^If the
1010 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1011 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1012 ** file control returns [SQLITE_OK], then the parser assumes that the
1013 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1014 ** prepared statement if result string is NULL, or that returns a copy
1015 ** of the result string if the string is non-NULL.
1016 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1017 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1018 ** that the VFS encountered an error while handling the [PRAGMA] and the
1019 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1020 ** file control occurs at the beginning of pragma statement analysis and so
1021 ** it is able to override built-in [PRAGMA] statements.
1023 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1024 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1025 ** file-control may be invoked by SQLite on the database file handle
1026 ** shortly after it is opened in order to provide a custom VFS with access
1027 ** to the connection's busy-handler callback. The argument is of type (void**)
1028 ** - an array of two (void *) values. The first (void *) actually points
1029 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1030 ** busy-handler, this function should be invoked with the second (void *) in
1031 ** the array as the only argument. If it returns non-zero, then the operation
1032 ** should be retried. If it returns zero, the custom VFS should abandon the
1033 ** current operation.
1035 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1036 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1037 ** to have SQLite generate a
1038 ** temporary filename using the same algorithm that is followed to generate
1039 ** temporary filenames for TEMP tables and other internal uses. The
1040 ** argument should be a char** which will be filled with the filename
1041 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1042 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1044 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1045 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1046 ** maximum number of bytes that will be used for memory-mapped I/O.
1047 ** The argument is a pointer to a value of type sqlite3_int64 that
1048 ** is an advisory maximum number of bytes in the file to memory map. The
1049 ** pointer is overwritten with the old value. The limit is not changed if
1050 ** the value originally pointed to is negative, and so the current limit
1051 ** can be queried by passing in a pointer to a negative number. This
1052 ** file-control is used internally to implement [PRAGMA mmap_size].
1054 ** <li>[[SQLITE_FCNTL_TRACE]]
1055 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1056 ** to the VFS about what the higher layers of the SQLite stack are doing.
1057 ** This file control is used by some VFS activity tracing [shims].
1058 ** The argument is a zero-terminated string. Higher layers in the
1059 ** SQLite stack may generate instances of this file control if
1060 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1062 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1063 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1064 ** pointer to an integer and it writes a boolean into that integer depending
1065 ** on whether or not the file has been renamed, moved, or deleted since it
1066 ** was first opened.
1068 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1069 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1070 ** underlying native file handle associated with a file handle. This file
1071 ** control interprets its argument as a pointer to a native file handle and
1072 ** writes the resulting value there.
1074 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1075 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1076 ** opcode causes the xFileControl method to swap the file handle with the one
1077 ** pointed to by the pArg argument. This capability is used during testing
1078 ** and only needs to be supported when SQLITE_TEST is defined.
1080 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1081 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1082 ** be advantageous to block on the next WAL lock if the lock is not immediately
1083 ** available. The WAL subsystem issues this signal during rare
1084 ** circumstances in order to fix a problem with priority inversion.
1085 ** Applications should <em>not</em> use this file-control.
1087 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1088 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1089 ** VFS should return SQLITE_NOTFOUND for this opcode.
1091 ** <li>[[SQLITE_FCNTL_RBU]]
1092 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1093 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1096 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1097 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1098 ** the file descriptor is placed in "batch write mode", which
1099 ** means all subsequent write operations will be deferred and done
1100 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1101 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1102 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1103 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1104 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1105 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1106 ** except for calls to the xWrite method and the xFileControl method
1107 ** with [SQLITE_FCNTL_SIZE_HINT].
1109 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1110 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1111 ** operations since the previous successful call to
1112 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1113 ** This file control returns [SQLITE_OK] if and only if the writes were
1114 ** all performed successfully and have been committed to persistent storage.
1115 ** ^Regardless of whether or not it is successful, this file control takes
1116 ** the file descriptor out of batch write mode so that all subsequent
1117 ** write operations are independent.
1118 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1119 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1121 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1122 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1123 ** operations since the previous successful call to
1124 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1125 ** ^This file control takes the file descriptor out of batch write mode
1126 ** so that all subsequent write operations are independent.
1127 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1128 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1130 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1131 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1132 ** to block for up to M milliseconds before failing when attempting to
1133 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1134 ** The parameter is a pointer to a 32-bit signed integer that contains
1135 ** the value that M is to be set to. Before returning, the 32-bit signed
1136 ** integer is overwritten with the previous value of M.
1138 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1139 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1140 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1141 ** The "data version" for the pager is written into the pointer. The
1142 ** "data version" changes whenever any change occurs to the corresponding
1143 ** database file, either through SQL statements on the same database
1144 ** connection or through transactions committed by separate database
1145 ** connections possibly in other processes. The [sqlite3_total_changes()]
1146 ** interface can be used to find if any database on the connection has changed,
1147 ** but that interface responds to changes on TEMP as well as MAIN and does
1148 ** not provide a mechanism to detect changes to MAIN only. Also, the
1149 ** [sqlite3_total_changes()] interface responds to internal changes only and
1150 ** omits changes made by other database connections. The
1151 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1152 ** a single attached database that occur due to other database connections,
1153 ** but omits changes implemented by the database connection on which it is
1154 ** called. This file control is the only mechanism to detect changes that
1155 ** happen either internally or externally and that are associated with
1156 ** a particular attached database.
1158 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1159 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1160 ** in wal mode before the client starts to copy pages from the wal
1161 ** file to the database file.
1163 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1164 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1165 ** in wal mode after the client has finished copying pages from the wal
1166 ** file to the database file, but before the *-shm file is updated to
1167 ** record the fact that the pages have been checkpointed.
1170 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1171 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1172 ** whether or not there is a database client in another process with a wal-mode
1173 ** transaction open on the database or not. It is only available on unix.The
1174 ** (void*) argument passed with this file-control should be a pointer to a
1175 ** value of type (int). The integer value is set to 1 if the database is a wal
1176 ** mode database and there exists at least one client in another process that
1177 ** currently has an SQL transaction open on the database. It is set to 0 if
1178 ** the database is not a wal-mode db, or if there is no such connection in any
1179 ** other process. This opcode cannot be used to detect transactions opened
1180 ** by clients within the current process, only within other processes.
1183 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1184 ** Used by the cksmvfs VFS module only.
1187 #define SQLITE_FCNTL_LOCKSTATE 1
1188 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1189 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1190 #define SQLITE_FCNTL_LAST_ERRNO 4
1191 #define SQLITE_FCNTL_SIZE_HINT 5
1192 #define SQLITE_FCNTL_CHUNK_SIZE 6
1193 #define SQLITE_FCNTL_FILE_POINTER 7
1194 #define SQLITE_FCNTL_SYNC_OMITTED 8
1195 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1196 #define SQLITE_FCNTL_PERSIST_WAL 10
1197 #define SQLITE_FCNTL_OVERWRITE 11
1198 #define SQLITE_FCNTL_VFSNAME 12
1199 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1200 #define SQLITE_FCNTL_PRAGMA 14
1201 #define SQLITE_FCNTL_BUSYHANDLER 15
1202 #define SQLITE_FCNTL_TEMPFILENAME 16
1203 #define SQLITE_FCNTL_MMAP_SIZE 18
1204 #define SQLITE_FCNTL_TRACE 19
1205 #define SQLITE_FCNTL_HAS_MOVED 20
1206 #define SQLITE_FCNTL_SYNC 21
1207 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1208 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1209 #define SQLITE_FCNTL_WAL_BLOCK 24
1210 #define SQLITE_FCNTL_ZIPVFS 25
1211 #define SQLITE_FCNTL_RBU 26
1212 #define SQLITE_FCNTL_VFS_POINTER 27
1213 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1214 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1215 #define SQLITE_FCNTL_PDB 30
1216 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1217 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1218 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1219 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1220 #define SQLITE_FCNTL_DATA_VERSION 35
1221 #define SQLITE_FCNTL_SIZE_LIMIT 36
1222 #define SQLITE_FCNTL_CKPT_DONE 37
1223 #define SQLITE_FCNTL_RESERVE_BYTES 38
1224 #define SQLITE_FCNTL_CKPT_START 39
1225 #define SQLITE_FCNTL_EXTERNAL_READER 40
1226 #define SQLITE_FCNTL_CKSM_FILE 41
1228 /* deprecated names */
1229 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1230 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1231 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1235 ** CAPI3REF: Mutex Handle
1237 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1238 ** abstract type for a mutex object. The SQLite core never looks
1239 ** at the internal representation of an [sqlite3_mutex]. It only
1240 ** deals with pointers to the [sqlite3_mutex] object.
1242 ** Mutexes are created using [sqlite3_mutex_alloc()].
1244 typedef struct sqlite3_mutex sqlite3_mutex;
1247 ** CAPI3REF: Loadable Extension Thunk
1249 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1250 ** the third parameter to entry points of [loadable extensions]. This
1251 ** structure must be typedefed in order to work around compiler warnings
1252 ** on some platforms.
1254 typedef struct sqlite3_api_routines sqlite3_api_routines;
1257 ** CAPI3REF: OS Interface Object
1259 ** An instance of the sqlite3_vfs object defines the interface between
1260 ** the SQLite core and the underlying operating system. The "vfs"
1261 ** in the name of the object stands for "virtual file system". See
1262 ** the [VFS | VFS documentation] for further information.
1264 ** The VFS interface is sometimes extended by adding new methods onto
1265 ** the end. Each time such an extension occurs, the iVersion field
1266 ** is incremented. The iVersion value started out as 1 in
1267 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1268 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1269 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1270 ** may be appended to the sqlite3_vfs object and the iVersion value
1271 ** may increase again in future versions of SQLite.
1272 ** Note that due to an oversight, the structure
1273 ** of the sqlite3_vfs object changed in the transition from
1274 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1275 ** and yet the iVersion field was not increased.
1277 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1278 ** structure used by this VFS. mxPathname is the maximum length of
1279 ** a pathname in this VFS.
1281 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1282 ** the pNext pointer. The [sqlite3_vfs_register()]
1283 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1284 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1285 ** searches the list. Neither the application code nor the VFS
1286 ** implementation should use the pNext pointer.
1288 ** The pNext field is the only field in the sqlite3_vfs
1289 ** structure that SQLite will ever modify. SQLite will only access
1290 ** or modify this field while holding a particular static mutex.
1291 ** The application should never modify anything within the sqlite3_vfs
1292 ** object once the object has been registered.
1294 ** The zName field holds the name of the VFS module. The name must
1295 ** be unique across all VFS modules.
1297 ** [[sqlite3_vfs.xOpen]]
1298 ** ^SQLite guarantees that the zFilename parameter to xOpen
1299 ** is either a NULL pointer or string obtained
1300 ** from xFullPathname() with an optional suffix added.
1301 ** ^If a suffix is added to the zFilename parameter, it will
1302 ** consist of a single "-" character followed by no more than
1303 ** 11 alphanumeric and/or "-" characters.
1304 ** ^SQLite further guarantees that
1305 ** the string will be valid and unchanged until xClose() is
1306 ** called. Because of the previous sentence,
1307 ** the [sqlite3_file] can safely store a pointer to the
1308 ** filename if it needs to remember the filename for some reason.
1309 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1310 ** must invent its own temporary name for the file. ^Whenever the
1311 ** xFilename parameter is NULL it will also be the case that the
1312 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1314 ** The flags argument to xOpen() includes all bits set in
1315 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1316 ** or [sqlite3_open16()] is used, then flags includes at least
1317 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1318 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1319 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1321 ** ^(SQLite will also add one of the following flags to the xOpen()
1322 ** call, depending on the object being opened:
1325 ** <li> [SQLITE_OPEN_MAIN_DB]
1326 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1327 ** <li> [SQLITE_OPEN_TEMP_DB]
1328 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1329 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1330 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1331 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1332 ** <li> [SQLITE_OPEN_WAL]
1335 ** The file I/O implementation can use the object type flags to
1336 ** change the way it deals with files. For example, an application
1337 ** that does not care about crash recovery or rollback might make
1338 ** the open of a journal file a no-op. Writes to this journal would
1339 ** also be no-ops, and any attempt to read the journal would return
1340 ** SQLITE_IOERR. Or the implementation might recognize that a database
1341 ** file will be doing page-aligned sector reads and writes in a random
1342 ** order and set up its I/O subsystem accordingly.
1344 ** SQLite might also add one of the following flags to the xOpen method:
1347 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1348 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1351 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1352 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1353 ** will be set for TEMP databases and their journals, transient
1354 ** databases, and subjournals.
1356 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1357 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1358 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1359 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1360 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1361 ** be created, and that it is an error if it already exists.
1362 ** It is <i>not</i> used to indicate the file should be opened
1363 ** for exclusive access.
1365 ** ^At least szOsFile bytes of memory are allocated by SQLite
1366 ** to hold the [sqlite3_file] structure passed as the third
1367 ** argument to xOpen. The xOpen method does not have to
1368 ** allocate the structure; it should just fill it in. Note that
1369 ** the xOpen method must set the sqlite3_file.pMethods to either
1370 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1371 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1372 ** element will be valid after xOpen returns regardless of the success
1373 ** or failure of the xOpen call.
1375 ** [[sqlite3_vfs.xAccess]]
1376 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1377 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1378 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1379 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1380 ** flag is never actually used and is not implemented in the built-in
1381 ** VFSes of SQLite. The file is named by the second argument and can be a
1382 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1383 ** non-zero error code if there is an I/O error or if the name of
1384 ** the file given in the second argument is illegal. If SQLITE_OK
1385 ** is returned, then non-zero or zero is written into *pResOut to indicate
1386 ** whether or not the file is accessible.
1388 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1389 ** output buffer xFullPathname. The exact size of the output buffer
1390 ** is also passed as a parameter to both methods. If the output buffer
1391 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1392 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1393 ** to prevent this by setting mxPathname to a sufficiently large value.
1395 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1396 ** interfaces are not strictly a part of the filesystem, but they are
1397 ** included in the VFS structure for completeness.
1398 ** The xRandomness() function attempts to return nBytes bytes
1399 ** of good-quality randomness into zOut. The return value is
1400 ** the actual number of bytes of randomness obtained.
1401 ** The xSleep() method causes the calling thread to sleep for at
1402 ** least the number of microseconds given. ^The xCurrentTime()
1403 ** method returns a Julian Day Number for the current date and time as
1404 ** a floating point value.
1405 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1406 ** Day Number multiplied by 86400000 (the number of milliseconds in
1408 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1409 ** date and time if that method is available (if iVersion is 2 or
1410 ** greater and the function pointer is not NULL) and will fall back
1411 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1413 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1414 ** are not used by the SQLite core. These optional interfaces are provided
1415 ** by some VFSes to facilitate testing of the VFS code. By overriding
1416 ** system calls with functions under its control, a test program can
1417 ** simulate faults and error conditions that would otherwise be difficult
1418 ** or impossible to induce. The set of system calls that can be overridden
1419 ** varies from one VFS to another, and from one version of the same VFS to the
1420 ** next. Applications that use these interfaces must be prepared for any
1421 ** or all of these interfaces to be NULL or for their behavior to change
1422 ** from one release to the next. Applications must not attempt to access
1423 ** any of these methods if the iVersion of the VFS is less than 3.
1425 typedef struct sqlite3_vfs sqlite3_vfs;
1426 typedef void (*sqlite3_syscall_ptr)(void);
1427 struct sqlite3_vfs {
1428 int iVersion; /* Structure version number (currently 3) */
1429 int szOsFile; /* Size of subclassed sqlite3_file */
1430 int mxPathname; /* Maximum file pathname length */
1431 sqlite3_vfs *pNext; /* Next registered VFS */
1432 const char *zName; /* Name of this virtual file system */
1433 void *pAppData; /* Pointer to application-specific data */
1434 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1435 int flags, int *pOutFlags);
1436 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1437 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1438 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1439 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1440 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1441 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1442 void (*xDlClose)(sqlite3_vfs*, void*);
1443 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1444 int (*xSleep)(sqlite3_vfs*, int microseconds);
1445 int (*xCurrentTime)(sqlite3_vfs*, double*);
1446 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1448 ** The methods above are in version 1 of the sqlite_vfs object
1449 ** definition. Those that follow are added in version 2 or later
1451 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1453 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1454 ** Those below are for version 3 and greater.
1456 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1457 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1458 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1460 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1461 ** New fields may be appended in future versions. The iVersion
1462 ** value will increment whenever this happens.
1467 ** CAPI3REF: Flags for the xAccess VFS method
1469 ** These integer constants can be used as the third parameter to
1470 ** the xAccess method of an [sqlite3_vfs] object. They determine
1471 ** what kind of permissions the xAccess method is looking for.
1472 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1473 ** simply checks whether the file exists.
1474 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1475 ** checks whether the named directory is both readable and writable
1476 ** (in other words, if files can be added, removed, and renamed within
1478 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1479 ** [temp_store_directory pragma], though this could change in a future
1480 ** release of SQLite.
1481 ** With SQLITE_ACCESS_READ, the xAccess method
1482 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1483 ** currently unused, though it might be used in a future release of
1486 #define SQLITE_ACCESS_EXISTS 0
1487 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1488 #define SQLITE_ACCESS_READ 2 /* Unused */
1491 ** CAPI3REF: Flags for the xShmLock VFS method
1493 ** These integer constants define the various locking operations
1494 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1495 ** following are the only legal combinations of flags to the
1499 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1500 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1501 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1502 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1505 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1506 ** was given on the corresponding lock.
1508 ** The xShmLock method can transition between unlocked and SHARED or
1509 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1512 #define SQLITE_SHM_UNLOCK 1
1513 #define SQLITE_SHM_LOCK 2
1514 #define SQLITE_SHM_SHARED 4
1515 #define SQLITE_SHM_EXCLUSIVE 8
1518 ** CAPI3REF: Maximum xShmLock index
1520 ** The xShmLock method on [sqlite3_io_methods] may use values
1521 ** between 0 and this upper bound as its "offset" argument.
1522 ** The SQLite core will never attempt to acquire or release a
1523 ** lock outside of this range
1525 #define SQLITE_SHM_NLOCK 8
1529 ** CAPI3REF: Initialize The SQLite Library
1531 ** ^The sqlite3_initialize() routine initializes the
1532 ** SQLite library. ^The sqlite3_shutdown() routine
1533 ** deallocates any resources that were allocated by sqlite3_initialize().
1534 ** These routines are designed to aid in process initialization and
1535 ** shutdown on embedded systems. Workstation applications using
1536 ** SQLite normally do not need to invoke either of these routines.
1538 ** A call to sqlite3_initialize() is an "effective" call if it is
1539 ** the first time sqlite3_initialize() is invoked during the lifetime of
1540 ** the process, or if it is the first time sqlite3_initialize() is invoked
1541 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1542 ** of sqlite3_initialize() does any initialization. All other calls
1543 ** are harmless no-ops.)^
1545 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1546 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1547 ** an effective call to sqlite3_shutdown() does any deinitialization.
1548 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1550 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1551 ** is not. The sqlite3_shutdown() interface must only be called from a
1552 ** single thread. All open [database connections] must be closed and all
1553 ** other SQLite resources must be deallocated prior to invoking
1554 ** sqlite3_shutdown().
1556 ** Among other things, ^sqlite3_initialize() will invoke
1557 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1558 ** will invoke sqlite3_os_end().
1560 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1561 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1562 ** the library (perhaps it is unable to allocate a needed resource such
1563 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1565 ** ^The sqlite3_initialize() routine is called internally by many other
1566 ** SQLite interfaces so that an application usually does not need to
1567 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1568 ** calls sqlite3_initialize() so the SQLite library will be automatically
1569 ** initialized when [sqlite3_open()] is called if it has not be initialized
1570 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1571 ** compile-time option, then the automatic calls to sqlite3_initialize()
1572 ** are omitted and the application must call sqlite3_initialize() directly
1573 ** prior to using any other SQLite interface. For maximum portability,
1574 ** it is recommended that applications always invoke sqlite3_initialize()
1575 ** directly prior to using any other SQLite interface. Future releases
1576 ** of SQLite may require this. In other words, the behavior exhibited
1577 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1578 ** default behavior in some future release of SQLite.
1580 ** The sqlite3_os_init() routine does operating-system specific
1581 ** initialization of the SQLite library. The sqlite3_os_end()
1582 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1583 ** performed by these routines include allocation or deallocation
1584 ** of static resources, initialization of global variables,
1585 ** setting up a default [sqlite3_vfs] module, or setting up
1586 ** a default configuration using [sqlite3_config()].
1588 ** The application should never invoke either sqlite3_os_init()
1589 ** or sqlite3_os_end() directly. The application should only invoke
1590 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1591 ** interface is called automatically by sqlite3_initialize() and
1592 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1593 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1594 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1595 ** When [custom builds | built for other platforms]
1596 ** (using the [SQLITE_OS_OTHER=1] compile-time
1597 ** option) the application must supply a suitable implementation for
1598 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1599 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1600 ** must return [SQLITE_OK] on success and some other [error code] upon
1603 SQLITE_API int sqlite3_initialize(void);
1604 SQLITE_API int sqlite3_shutdown(void);
1605 SQLITE_API int sqlite3_os_init(void);
1606 SQLITE_API int sqlite3_os_end(void);
1609 ** CAPI3REF: Configuring The SQLite Library
1611 ** The sqlite3_config() interface is used to make global configuration
1612 ** changes to SQLite in order to tune SQLite to the specific needs of
1613 ** the application. The default configuration is recommended for most
1614 ** applications and so this routine is usually not necessary. It is
1615 ** provided to support rare applications with unusual needs.
1617 ** <b>The sqlite3_config() interface is not threadsafe. The application
1618 ** must ensure that no other SQLite interfaces are invoked by other
1619 ** threads while sqlite3_config() is running.</b>
1621 ** The sqlite3_config() interface
1622 ** may only be invoked prior to library initialization using
1623 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1624 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1625 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1626 ** Note, however, that ^sqlite3_config() can be called as part of the
1627 ** implementation of an application-defined [sqlite3_os_init()].
1629 ** The first argument to sqlite3_config() is an integer
1630 ** [configuration option] that determines
1631 ** what property of SQLite is to be configured. Subsequent arguments
1632 ** vary depending on the [configuration option]
1633 ** in the first argument.
1635 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1636 ** ^If the option is unknown or SQLite is unable to set the option
1637 ** then this routine returns a non-zero [error code].
1639 SQLITE_API int sqlite3_config(int, ...);
1642 ** CAPI3REF: Configure database connections
1645 ** The sqlite3_db_config() interface is used to make configuration
1646 ** changes to a [database connection]. The interface is similar to
1647 ** [sqlite3_config()] except that the changes apply to a single
1648 ** [database connection] (specified in the first argument).
1650 ** The second argument to sqlite3_db_config(D,V,...) is the
1651 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1652 ** that indicates what aspect of the [database connection] is being configured.
1653 ** Subsequent arguments vary depending on the configuration verb.
1655 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1656 ** the call is considered successful.
1658 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1661 ** CAPI3REF: Memory Allocation Routines
1663 ** An instance of this object defines the interface between SQLite
1664 ** and low-level memory allocation routines.
1666 ** This object is used in only one place in the SQLite interface.
1667 ** A pointer to an instance of this object is the argument to
1668 ** [sqlite3_config()] when the configuration option is
1669 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1670 ** By creating an instance of this object
1671 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1672 ** during configuration, an application can specify an alternative
1673 ** memory allocation subsystem for SQLite to use for all of its
1674 ** dynamic memory needs.
1676 ** Note that SQLite comes with several [built-in memory allocators]
1677 ** that are perfectly adequate for the overwhelming majority of applications
1678 ** and that this object is only useful to a tiny minority of applications
1679 ** with specialized memory allocation requirements. This object is
1680 ** also used during testing of SQLite in order to specify an alternative
1681 ** memory allocator that simulates memory out-of-memory conditions in
1682 ** order to verify that SQLite recovers gracefully from such
1685 ** The xMalloc, xRealloc, and xFree methods must work like the
1686 ** malloc(), realloc() and free() functions from the standard C library.
1687 ** ^SQLite guarantees that the second argument to
1688 ** xRealloc is always a value returned by a prior call to xRoundup.
1690 ** xSize should return the allocated size of a memory allocation
1691 ** previously obtained from xMalloc or xRealloc. The allocated size
1692 ** is always at least as big as the requested size but may be larger.
1694 ** The xRoundup method returns what would be the allocated size of
1695 ** a memory allocation given a particular requested size. Most memory
1696 ** allocators round up memory allocations at least to the next multiple
1697 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1698 ** Every memory allocation request coming in through [sqlite3_malloc()]
1699 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1700 ** that causes the corresponding memory allocation to fail.
1702 ** The xInit method initializes the memory allocator. For example,
1703 ** it might allocate any required mutexes or initialize internal data
1704 ** structures. The xShutdown method is invoked (indirectly) by
1705 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1706 ** by xInit. The pAppData pointer is used as the only parameter to
1707 ** xInit and xShutdown.
1709 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1710 ** the xInit method, so the xInit method need not be threadsafe. The
1711 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1712 ** not need to be threadsafe either. For all other methods, SQLite
1713 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1714 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1715 ** it is by default) and so the methods are automatically serialized.
1716 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1717 ** methods must be threadsafe or else make their own arrangements for
1720 ** SQLite will never invoke xInit() more than once without an intervening
1721 ** call to xShutdown().
1723 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1724 struct sqlite3_mem_methods {
1725 void *(*xMalloc)(int); /* Memory allocation function */
1726 void (*xFree)(void*); /* Free a prior allocation */
1727 void *(*xRealloc)(void*,int); /* Resize an allocation */
1728 int (*xSize)(void*); /* Return the size of an allocation */
1729 int (*xRoundup)(int); /* Round up request size to allocation size */
1730 int (*xInit)(void*); /* Initialize the memory allocator */
1731 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1732 void *pAppData; /* Argument to xInit() and xShutdown() */
1736 ** CAPI3REF: Configuration Options
1737 ** KEYWORDS: {configuration option}
1739 ** These constants are the available integer configuration options that
1740 ** can be passed as the first argument to the [sqlite3_config()] interface.
1742 ** New configuration options may be added in future releases of SQLite.
1743 ** Existing configuration options might be discontinued. Applications
1744 ** should check the return code from [sqlite3_config()] to make sure that
1745 ** the call worked. The [sqlite3_config()] interface will return a
1746 ** non-zero [error code] if a discontinued or unsupported configuration option
1750 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1751 ** <dd>There are no arguments to this option. ^This option sets the
1752 ** [threading mode] to Single-thread. In other words, it disables
1753 ** all mutexing and puts SQLite into a mode where it can only be used
1754 ** by a single thread. ^If SQLite is compiled with
1755 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1756 ** it is not possible to change the [threading mode] from its default
1757 ** value of Single-thread and so [sqlite3_config()] will return
1758 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1759 ** configuration option.</dd>
1761 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1762 ** <dd>There are no arguments to this option. ^This option sets the
1763 ** [threading mode] to Multi-thread. In other words, it disables
1764 ** mutexing on [database connection] and [prepared statement] objects.
1765 ** The application is responsible for serializing access to
1766 ** [database connections] and [prepared statements]. But other mutexes
1767 ** are enabled so that SQLite will be safe to use in a multi-threaded
1768 ** environment as long as no two threads attempt to use the same
1769 ** [database connection] at the same time. ^If SQLite is compiled with
1770 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1771 ** it is not possible to set the Multi-thread [threading mode] and
1772 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1773 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1775 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1776 ** <dd>There are no arguments to this option. ^This option sets the
1777 ** [threading mode] to Serialized. In other words, this option enables
1778 ** all mutexes including the recursive
1779 ** mutexes on [database connection] and [prepared statement] objects.
1780 ** In this mode (which is the default when SQLite is compiled with
1781 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1782 ** to [database connections] and [prepared statements] so that the
1783 ** application is free to use the same [database connection] or the
1784 ** same [prepared statement] in different threads at the same time.
1785 ** ^If SQLite is compiled with
1786 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1787 ** it is not possible to set the Serialized [threading mode] and
1788 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1789 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1791 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1792 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1793 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1794 ** The argument specifies
1795 ** alternative low-level memory allocation routines to be used in place of
1796 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1797 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1798 ** before the [sqlite3_config()] call returns.</dd>
1800 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1801 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1802 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1803 ** The [sqlite3_mem_methods]
1804 ** structure is filled with the currently defined memory allocation routines.)^
1805 ** This option can be used to overload the default memory allocation
1806 ** routines with a wrapper that simulations memory allocation failure or
1807 ** tracks memory usage, for example. </dd>
1809 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1810 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1811 ** type int, interpreted as a boolean, which if true provides a hint to
1812 ** SQLite that it should avoid large memory allocations if possible.
1813 ** SQLite will run faster if it is free to make large memory allocations,
1814 ** but some application might prefer to run slower in exchange for
1815 ** guarantees about memory fragmentation that are possible if large
1816 ** allocations are avoided. This hint is normally off.
1819 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1820 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1821 ** interpreted as a boolean, which enables or disables the collection of
1822 ** memory allocation statistics. ^(When memory allocation statistics are
1823 ** disabled, the following SQLite interfaces become non-operational:
1825 ** <li> [sqlite3_hard_heap_limit64()]
1826 ** <li> [sqlite3_memory_used()]
1827 ** <li> [sqlite3_memory_highwater()]
1828 ** <li> [sqlite3_soft_heap_limit64()]
1829 ** <li> [sqlite3_status64()]
1831 ** ^Memory allocation statistics are enabled by default unless SQLite is
1832 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1833 ** allocation statistics are disabled by default.
1836 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1837 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1840 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1841 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1842 ** that SQLite can use for the database page cache with the default page
1843 ** cache implementation.
1844 ** This configuration option is a no-op if an application-defined page
1845 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1846 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1847 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1848 ** and the number of cache lines (N).
1849 ** The sz argument should be the size of the largest database page
1850 ** (a power of two between 512 and 65536) plus some extra bytes for each
1851 ** page header. ^The number of extra bytes needed by the page header
1852 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1853 ** ^It is harmless, apart from the wasted memory,
1854 ** for the sz parameter to be larger than necessary. The pMem
1855 ** argument must be either a NULL pointer or a pointer to an 8-byte
1856 ** aligned block of memory of at least sz*N bytes, otherwise
1857 ** subsequent behavior is undefined.
1858 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1859 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1860 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1862 ** ^If pMem is NULL and N is non-zero, then each database connection
1863 ** does an initial bulk allocation for page cache memory
1864 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1865 ** of -1024*N bytes if N is negative, . ^If additional
1866 ** page cache memory is needed beyond what is provided by the initial
1867 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1868 ** additional cache line. </dd>
1870 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1871 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1872 ** that SQLite will use for all of its dynamic memory allocation needs
1873 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1874 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1875 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1876 ** [SQLITE_ERROR] if invoked otherwise.
1877 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1878 ** An 8-byte aligned pointer to the memory,
1879 ** the number of bytes in the memory buffer, and the minimum allocation size.
1880 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1881 ** to using its default memory allocator (the system malloc() implementation),
1882 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1883 ** memory pointer is not NULL then the alternative memory
1884 ** allocator is engaged to handle all of SQLites memory allocation needs.
1885 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1886 ** boundary or subsequent behavior of SQLite will be undefined.
1887 ** The minimum allocation size is capped at 2**12. Reasonable values
1888 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1890 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1891 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1892 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1893 ** The argument specifies alternative low-level mutex routines to be used
1894 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1895 ** the content of the [sqlite3_mutex_methods] structure before the call to
1896 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1897 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1898 ** the entire mutexing subsystem is omitted from the build and hence calls to
1899 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1900 ** return [SQLITE_ERROR].</dd>
1902 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1903 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1904 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1905 ** [sqlite3_mutex_methods]
1906 ** structure is filled with the currently defined mutex routines.)^
1907 ** This option can be used to overload the default mutex allocation
1908 ** routines with a wrapper used to track mutex usage for performance
1909 ** profiling or testing, for example. ^If SQLite is compiled with
1910 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1911 ** the entire mutexing subsystem is omitted from the build and hence calls to
1912 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1913 ** return [SQLITE_ERROR].</dd>
1915 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1916 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1917 ** the default size of lookaside memory on each [database connection].
1918 ** The first argument is the
1919 ** size of each lookaside buffer slot and the second is the number of
1920 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1921 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1922 ** option to [sqlite3_db_config()] can be used to change the lookaside
1923 ** configuration on individual connections.)^ </dd>
1925 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1926 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1927 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1928 ** the interface to a custom page cache implementation.)^
1929 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1931 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1932 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1933 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1934 ** the current page cache implementation into that object.)^ </dd>
1936 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1937 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1938 ** global [error log].
1939 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1940 ** function with a call signature of void(*)(void*,int,const char*),
1941 ** and a pointer to void. ^If the function pointer is not NULL, it is
1942 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1943 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1944 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1945 ** passed through as the first parameter to the application-defined logger
1946 ** function whenever that function is invoked. ^The second parameter to
1947 ** the logger function is a copy of the first parameter to the corresponding
1948 ** [sqlite3_log()] call and is intended to be a [result code] or an
1949 ** [extended result code]. ^The third parameter passed to the logger is
1950 ** log message after formatting via [sqlite3_snprintf()].
1951 ** The SQLite logging interface is not reentrant; the logger function
1952 ** supplied by the application must not invoke any SQLite interface.
1953 ** In a multi-threaded application, the application-defined logger
1954 ** function must be threadsafe. </dd>
1956 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1957 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1958 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1959 ** then URI handling is globally disabled.)^ ^If URI handling is globally
1960 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1961 ** [sqlite3_open16()] or
1962 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1963 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1964 ** connection is opened. ^If it is globally disabled, filenames are
1965 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1966 ** database connection is opened. ^(By default, URI handling is globally
1967 ** disabled. The default value may be changed by compiling with the
1968 ** [SQLITE_USE_URI] symbol defined.)^
1970 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1971 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1972 ** argument which is interpreted as a boolean in order to enable or disable
1973 ** the use of covering indices for full table scans in the query optimizer.
1974 ** ^The default setting is determined
1975 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1976 ** if that compile-time option is omitted.
1977 ** The ability to disable the use of covering indices for full table scans
1978 ** is because some incorrectly coded legacy applications might malfunction
1979 ** when the optimization is enabled. Providing the ability to
1980 ** disable the optimization allows the older, buggy application code to work
1981 ** without change even with newer versions of SQLite.
1983 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1984 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1985 ** <dd> These options are obsolete and should not be used by new code.
1986 ** They are retained for backwards compatibility but are now no-ops.
1989 ** [[SQLITE_CONFIG_SQLLOG]]
1990 ** <dt>SQLITE_CONFIG_SQLLOG
1991 ** <dd>This option is only available if sqlite is compiled with the
1992 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1993 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1994 ** The second should be of type (void*). The callback is invoked by the library
1995 ** in three separate circumstances, identified by the value passed as the
1996 ** fourth parameter. If the fourth parameter is 0, then the database connection
1997 ** passed as the second argument has just been opened. The third argument
1998 ** points to a buffer containing the name of the main database file. If the
1999 ** fourth parameter is 1, then the SQL statement that the third parameter
2000 ** points to has just been executed. Or, if the fourth parameter is 2, then
2001 ** the connection being passed as the second parameter is being closed. The
2002 ** third parameter is passed NULL In this case. An example of using this
2003 ** configuration option can be seen in the "test_sqllog.c" source file in
2004 ** the canonical SQLite source tree.</dd>
2006 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2007 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2008 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2009 ** that are the default mmap size limit (the default setting for
2010 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2011 ** ^The default setting can be overridden by each database connection using
2012 ** either the [PRAGMA mmap_size] command, or by using the
2013 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2014 ** will be silently truncated if necessary so that it does not exceed the
2015 ** compile-time maximum mmap size set by the
2016 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2017 ** ^If either argument to this option is negative, then that argument is
2018 ** changed to its compile-time default.
2020 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2021 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2022 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2023 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2024 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2025 ** that specifies the maximum size of the created heap.
2027 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2028 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2029 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2030 ** is a pointer to an integer and writes into that integer the number of extra
2031 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2032 ** The amount of extra space required can change depending on the compiler,
2033 ** target platform, and SQLite version.
2035 ** [[SQLITE_CONFIG_PMASZ]]
2036 ** <dt>SQLITE_CONFIG_PMASZ
2037 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2038 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2039 ** sorter to that integer. The default minimum PMA Size is set by the
2040 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2041 ** to help with sort operations when multithreaded sorting
2042 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2043 ** to be sorted exceeds the page size times the minimum of the
2044 ** [PRAGMA cache_size] setting and this value.
2046 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2047 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2048 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2049 ** becomes the [statement journal] spill-to-disk threshold.
2050 ** [Statement journals] are held in memory until their size (in bytes)
2051 ** exceeds this threshold, at which point they are written to disk.
2052 ** Or if the threshold is -1, statement journals are always held
2053 ** exclusively in memory.
2054 ** Since many statement journals never become large, setting the spill
2055 ** threshold to a value such as 64KiB can greatly reduce the amount of
2056 ** I/O required to support statement rollback.
2057 ** The default value for this setting is controlled by the
2058 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2060 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2061 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2062 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2063 ** of type (int) - the new value of the sorter-reference size threshold.
2064 ** Usually, when SQLite uses an external sort to order records according
2065 ** to an ORDER BY clause, all fields required by the caller are present in the
2066 ** sorted records. However, if SQLite determines based on the declared type
2067 ** of a table column that its values are likely to be very large - larger
2068 ** than the configured sorter-reference size threshold - then a reference
2069 ** is stored in each sorted record and the required column values loaded
2070 ** from the database as records are returned in sorted order. The default
2071 ** value for this option is to never use this optimization. Specifying a
2072 ** negative value for this option restores the default behaviour.
2073 ** This option is only available if SQLite is compiled with the
2074 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2076 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2077 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2078 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2079 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2080 ** database created using [sqlite3_deserialize()]. This default maximum
2081 ** size can be adjusted up or down for individual databases using the
2082 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2083 ** configuration setting is never used, then the default maximum is determined
2084 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2085 ** compile-time option is not set, then the default maximum is 1073741824.
2088 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2089 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2090 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2091 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2092 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2093 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2094 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2095 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2096 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2097 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2098 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2099 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2100 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2101 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2102 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2103 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2104 #define SQLITE_CONFIG_URI 17 /* int */
2105 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2106 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2107 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2108 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2109 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2110 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2111 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2112 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2113 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2114 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2115 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2116 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2119 ** CAPI3REF: Database Connection Configuration Options
2121 ** These constants are the available integer configuration options that
2122 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2124 ** New configuration options may be added in future releases of SQLite.
2125 ** Existing configuration options might be discontinued. Applications
2126 ** should check the return code from [sqlite3_db_config()] to make sure that
2127 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2128 ** non-zero [error code] if a discontinued or unsupported configuration option
2132 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2133 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2134 ** <dd> ^This option takes three additional arguments that determine the
2135 ** [lookaside memory allocator] configuration for the [database connection].
2136 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2137 ** pointer to a memory buffer to use for lookaside memory.
2138 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2139 ** may be NULL in which case SQLite will allocate the
2140 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2141 ** size of each lookaside buffer slot. ^The third argument is the number of
2142 ** slots. The size of the buffer in the first argument must be greater than
2143 ** or equal to the product of the second and third arguments. The buffer
2144 ** must be aligned to an 8-byte boundary. ^If the second argument to
2145 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2146 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2147 ** configuration for a database connection can only be changed when that
2148 ** connection is not currently using lookaside memory, or in other words
2149 ** when the "current value" returned by
2150 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2151 ** Any attempt to change the lookaside memory configuration when lookaside
2152 ** memory is in use leaves the configuration unchanged and returns
2153 ** [SQLITE_BUSY].)^</dd>
2155 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2156 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2157 ** <dd> ^This option is used to enable or disable the enforcement of
2158 ** [foreign key constraints]. There should be two additional arguments.
2159 ** The first argument is an integer which is 0 to disable FK enforcement,
2160 ** positive to enable FK enforcement or negative to leave FK enforcement
2161 ** unchanged. The second parameter is a pointer to an integer into which
2162 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2163 ** following this call. The second parameter may be a NULL pointer, in
2164 ** which case the FK enforcement setting is not reported back. </dd>
2166 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2167 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2168 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2169 ** There should be two additional arguments.
2170 ** The first argument is an integer which is 0 to disable triggers,
2171 ** positive to enable triggers or negative to leave the setting unchanged.
2172 ** The second parameter is a pointer to an integer into which
2173 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2174 ** following this call. The second parameter may be a NULL pointer, in
2175 ** which case the trigger setting is not reported back.
2177 ** <p>Originally this option disabled all triggers. ^(However, since
2178 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2179 ** this option is off. So, in other words, this option now only disables
2180 ** triggers in the main database schema or in the schemas of ATTACH-ed
2181 ** databases.)^ </dd>
2183 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2184 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2185 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2186 ** There should be two additional arguments.
2187 ** The first argument is an integer which is 0 to disable views,
2188 ** positive to enable views or negative to leave the setting unchanged.
2189 ** The second parameter is a pointer to an integer into which
2190 ** is written 0 or 1 to indicate whether views are disabled or enabled
2191 ** following this call. The second parameter may be a NULL pointer, in
2192 ** which case the view setting is not reported back.
2194 ** <p>Originally this option disabled all views. ^(However, since
2195 ** SQLite version 3.35.0, TEMP views are still allowed even if
2196 ** this option is off. So, in other words, this option now only disables
2197 ** views in the main database schema or in the schemas of ATTACH-ed
2198 ** databases.)^ </dd>
2200 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2201 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2202 ** <dd> ^This option is used to enable or disable the
2203 ** [fts3_tokenizer()] function which is part of the
2204 ** [FTS3] full-text search engine extension.
2205 ** There should be two additional arguments.
2206 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2207 ** positive to enable fts3_tokenizer() or negative to leave the setting
2209 ** The second parameter is a pointer to an integer into which
2210 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2211 ** following this call. The second parameter may be a NULL pointer, in
2212 ** which case the new setting is not reported back. </dd>
2214 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2215 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2216 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2217 ** interface independently of the [load_extension()] SQL function.
2218 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2219 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2220 ** There should be two additional arguments.
2221 ** When the first argument to this interface is 1, then only the C-API is
2222 ** enabled and the SQL function remains disabled. If the first argument to
2223 ** this interface is 0, then both the C-API and the SQL function are disabled.
2224 ** If the first argument is -1, then no changes are made to state of either the
2225 ** C-API or the SQL function.
2226 ** The second parameter is a pointer to an integer into which
2227 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2228 ** is disabled or enabled following this call. The second parameter may
2229 ** be a NULL pointer, in which case the new setting is not reported back.
2232 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2233 ** <dd> ^This option is used to change the name of the "main" database
2234 ** schema. ^The sole argument is a pointer to a constant UTF8 string
2235 ** which will become the new schema name in place of "main". ^SQLite
2236 ** does not make a copy of the new main schema name string, so the application
2237 ** must ensure that the argument passed into this DBCONFIG option is unchanged
2238 ** until after the database connection closes.
2241 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2242 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2243 ** <dd> Usually, when a database in wal mode is closed or detached from a
2244 ** database handle, SQLite checks if this will mean that there are now no
2245 ** connections at all to the database. If so, it performs a checkpoint
2246 ** operation before closing the connection. This option may be used to
2247 ** override this behaviour. The first parameter passed to this operation
2248 ** is an integer - positive to disable checkpoints-on-close, or zero (the
2249 ** default) to enable them, and negative to leave the setting unchanged.
2250 ** The second parameter is a pointer to an integer
2251 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2252 ** have been disabled - 0 if they are not disabled, 1 if they are.
2255 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2256 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2257 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2258 ** a single SQL query statement will always use the same algorithm regardless
2259 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2260 ** that look at the values of bound parameters, which can make some queries
2261 ** slower. But the QPSG has the advantage of more predictable behavior. With
2262 ** the QPSG active, SQLite will always use the same query plan in the field as
2263 ** was used during testing in the lab.
2264 ** The first argument to this setting is an integer which is 0 to disable
2265 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2266 ** unchanged. The second parameter is a pointer to an integer into which
2267 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2268 ** following this call.
2271 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2272 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2273 ** include output for any operations performed by trigger programs. This
2274 ** option is used to set or clear (the default) a flag that governs this
2275 ** behavior. The first parameter passed to this operation is an integer -
2276 ** positive to enable output for trigger programs, or zero to disable it,
2277 ** or negative to leave the setting unchanged.
2278 ** The second parameter is a pointer to an integer into which is written
2279 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2280 ** it is not disabled, 1 if it is.
2283 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2284 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2285 ** [VACUUM] in order to reset a database back to an empty database
2286 ** with no schema and no content. The following process works even for
2287 ** a badly corrupted database file:
2289 ** <li> If the database connection is newly opened, make sure it has read the
2290 ** database schema by preparing then discarding some query against the
2291 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2292 ** errors. This step is only necessary if the application desires to keep
2293 ** the database in WAL mode after the reset if it was in WAL mode before
2295 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2296 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2297 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2299 ** Because resetting a database is destructive and irreversible, the
2300 ** process requires the use of this obscure API and multiple steps to help
2301 ** ensure that it does not happen by accident.
2303 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2304 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2305 ** "defensive" flag for a database connection. When the defensive
2306 ** flag is enabled, language features that allow ordinary SQL to
2307 ** deliberately corrupt the database file are disabled. The disabled
2308 ** features include but are not limited to the following:
2310 ** <li> The [PRAGMA writable_schema=ON] statement.
2311 ** <li> The [PRAGMA journal_mode=OFF] statement.
2312 ** <li> Writes to the [sqlite_dbpage] virtual table.
2313 ** <li> Direct writes to [shadow tables].
2317 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2318 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2319 ** "writable_schema" flag. This has the same effect and is logically equivalent
2320 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2321 ** The first argument to this setting is an integer which is 0 to disable
2322 ** the writable_schema, positive to enable writable_schema, or negative to
2323 ** leave the setting unchanged. The second parameter is a pointer to an
2324 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2325 ** is enabled or disabled following this call.
2328 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2329 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2330 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2331 ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2332 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2333 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2334 ** additional information. This feature can also be turned on and off
2335 ** using the [PRAGMA legacy_alter_table] statement.
2338 ** [[SQLITE_DBCONFIG_DQS_DML]]
2339 ** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2340 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2341 ** the legacy [double-quoted string literal] misfeature for DML statements
2342 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2343 ** default value of this setting is determined by the [-DSQLITE_DQS]
2344 ** compile-time option.
2347 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2348 ** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2349 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2350 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2351 ** such as CREATE TABLE and CREATE INDEX. The
2352 ** default value of this setting is determined by the [-DSQLITE_DQS]
2353 ** compile-time option.
2356 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2357 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2358 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2359 ** assume that database schemas are untainted by malicious content.
2360 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2361 ** takes additional defensive steps to protect the application from harm
2364 ** <li> Prohibit the use of SQL functions inside triggers, views,
2365 ** CHECK constraints, DEFAULT clauses, expression indexes,
2366 ** partial indexes, or generated columns
2367 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2368 ** <li> Prohibit the use of virtual tables inside of triggers or views
2369 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2371 ** This setting defaults to "on" for legacy compatibility, however
2372 ** all applications are advised to turn it off if possible. This setting
2373 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2376 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2377 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2378 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2379 ** the legacy file format flag. When activated, this flag causes all newly
2380 ** created database file to have a schema format version number (the 4-byte
2381 ** integer found at offset 44 into the database header) of 1. This in turn
2382 ** means that the resulting database file will be readable and writable by
2383 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2384 ** newly created databases are generally not understandable by SQLite versions
2385 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2386 ** is now scarcely any need to generated database files that are compatible
2387 ** all the way back to version 3.0.0, and so this setting is of little
2388 ** practical use, but is provided so that SQLite can continue to claim the
2389 ** ability to generate new database files that are compatible with version
2391 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2392 ** the [VACUUM] command will fail with an obscure error when attempting to
2393 ** process a table with generated columns and a descending index. This is
2394 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2395 ** either generated columns or decending indexes.
2399 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2400 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2401 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2402 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2403 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2404 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2405 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2406 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2407 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2408 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2409 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2410 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2411 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2412 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2413 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2414 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2415 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2416 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2417 #define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2420 ** CAPI3REF: Enable Or Disable Extended Result Codes
2423 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2424 ** [extended result codes] feature of SQLite. ^The extended result
2425 ** codes are disabled by default for historical compatibility.
2427 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2430 ** CAPI3REF: Last Insert Rowid
2433 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2434 ** has a unique 64-bit signed
2435 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2436 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2437 ** names are not also used by explicitly declared columns. ^If
2438 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2439 ** is another alias for the rowid.
2441 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2442 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2443 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2444 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2445 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2448 ** As well as being set automatically as rows are inserted into database
2449 ** tables, the value returned by this function may be set explicitly by
2450 ** [sqlite3_set_last_insert_rowid()]
2452 ** Some virtual table implementations may INSERT rows into rowid tables as
2453 ** part of committing a transaction (e.g. to flush data accumulated in memory
2454 ** to disk). In this case subsequent calls to this function return the rowid
2455 ** associated with these internal INSERT operations, which leads to
2456 ** unintuitive results. Virtual table implementations that do write to rowid
2457 ** tables in this way can avoid this problem by restoring the original
2458 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2459 ** control to the user.
2461 ** ^(If an [INSERT] occurs within a trigger then this routine will
2462 ** return the [rowid] of the inserted row as long as the trigger is
2463 ** running. Once the trigger program ends, the value returned
2464 ** by this routine reverts to what it was before the trigger was fired.)^
2466 ** ^An [INSERT] that fails due to a constraint violation is not a
2467 ** successful [INSERT] and does not change the value returned by this
2468 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2469 ** and INSERT OR ABORT make no changes to the return value of this
2470 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2471 ** encounters a constraint violation, it does not fail. The
2472 ** INSERT continues to completion after deleting rows that caused
2473 ** the constraint problem so INSERT OR REPLACE will always change
2474 ** the return value of this interface.)^
2476 ** ^For the purposes of this routine, an [INSERT] is considered to
2477 ** be successful even if it is subsequently rolled back.
2479 ** This function is accessible to SQL statements via the
2480 ** [last_insert_rowid() SQL function].
2482 ** If a separate thread performs a new [INSERT] on the same
2483 ** database connection while the [sqlite3_last_insert_rowid()]
2484 ** function is running and thus changes the last insert [rowid],
2485 ** then the value returned by [sqlite3_last_insert_rowid()] is
2486 ** unpredictable and might not equal either the old or the new
2487 ** last insert [rowid].
2489 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2492 ** CAPI3REF: Set the Last Insert Rowid value.
2495 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2496 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2497 ** without inserting a row into the database.
2499 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2502 ** CAPI3REF: Count The Number Of Rows Modified
2505 ** ^These functions return the number of rows modified, inserted or
2506 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2507 ** statement on the database connection specified by the only parameter.
2508 ** The two functions are identical except for the type of the return value
2509 ** and that if the number of rows modified by the most recent INSERT, UPDATE
2510 ** or DELETE is greater than the maximum value supported by type "int", then
2511 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2512 ** type of SQL statement does not modify the value returned by these functions.
2514 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2515 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2516 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2518 ** Changes to a view that are intercepted by
2519 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2520 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2521 ** DELETE statement run on a view is always zero. Only changes made to real
2522 ** tables are counted.
2524 ** Things are more complicated if the sqlite3_changes() function is
2525 ** executed while a trigger program is running. This may happen if the
2526 ** program uses the [changes() SQL function], or if some other callback
2527 ** function invokes sqlite3_changes() directly. Essentially:
2530 ** <li> ^(Before entering a trigger program the value returned by
2531 ** sqlite3_changes() function is saved. After the trigger program
2532 ** has finished, the original value is restored.)^
2534 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2535 ** statement sets the value returned by sqlite3_changes()
2536 ** upon completion as normal. Of course, this value will not include
2537 ** any changes performed by sub-triggers, as the sqlite3_changes()
2538 ** value will be saved and restored after each sub-trigger has run.)^
2541 ** ^This means that if the changes() SQL function (or similar) is used
2542 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2543 ** returns the value as set when the calling statement began executing.
2544 ** ^If it is used by the second or subsequent such statement within a trigger
2545 ** program, the value returned reflects the number of rows modified by the
2546 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2548 ** If a separate thread makes changes on the same database connection
2549 ** while [sqlite3_changes()] is running then the value returned
2550 ** is unpredictable and not meaningful.
2554 ** <li> the [sqlite3_total_changes()] interface
2555 ** <li> the [count_changes pragma]
2556 ** <li> the [changes() SQL function]
2557 ** <li> the [data_version pragma]
2560 SQLITE_API int sqlite3_changes(sqlite3*);
2561 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2564 ** CAPI3REF: Total Number Of Rows Modified
2567 ** ^These functions return the total number of rows inserted, modified or
2568 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2569 ** since the database connection was opened, including those executed as
2570 ** part of trigger programs. The two functions are identical except for the
2571 ** type of the return value and that if the number of rows modified by the
2572 ** connection exceeds the maximum value supported by type "int", then
2573 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2574 ** any other type of SQL statement does not affect the value returned by
2575 ** sqlite3_total_changes().
2577 ** ^Changes made as part of [foreign key actions] are included in the
2578 ** count, but those made as part of REPLACE constraint resolution are
2579 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2582 ** The [sqlite3_total_changes(D)] interface only reports the number
2583 ** of rows that changed due to SQL statement run against database
2584 ** connection D. Any changes by other database connections are ignored.
2585 ** To detect changes against a database file from other database
2586 ** connections use the [PRAGMA data_version] command or the
2587 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2589 ** If a separate thread makes changes on the same database connection
2590 ** while [sqlite3_total_changes()] is running then the value
2591 ** returned is unpredictable and not meaningful.
2595 ** <li> the [sqlite3_changes()] interface
2596 ** <li> the [count_changes pragma]
2597 ** <li> the [changes() SQL function]
2598 ** <li> the [data_version pragma]
2599 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2602 SQLITE_API int sqlite3_total_changes(sqlite3*);
2603 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2606 ** CAPI3REF: Interrupt A Long-Running Query
2609 ** ^This function causes any pending database operation to abort and
2610 ** return at its earliest opportunity. This routine is typically
2611 ** called in response to a user action such as pressing "Cancel"
2612 ** or Ctrl-C where the user wants a long query operation to halt
2615 ** ^It is safe to call this routine from a thread different from the
2616 ** thread that is currently running the database operation. But it
2617 ** is not safe to call this routine with a [database connection] that
2618 ** is closed or might close before sqlite3_interrupt() returns.
2620 ** ^If an SQL operation is very nearly finished at the time when
2621 ** sqlite3_interrupt() is called, then it might not have an opportunity
2622 ** to be interrupted and might continue to completion.
2624 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2625 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2626 ** that is inside an explicit transaction, then the entire transaction
2627 ** will be rolled back automatically.
2629 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2630 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2631 ** that are started after the sqlite3_interrupt() call and before the
2632 ** running statement count reaches zero are interrupted as if they had been
2633 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2634 ** that are started after the running statement count reaches zero are
2635 ** not effected by the sqlite3_interrupt().
2636 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2637 ** SQL statements is a no-op and has no effect on SQL statements
2638 ** that are started after the sqlite3_interrupt() call returns.
2640 SQLITE_API void sqlite3_interrupt(sqlite3*);
2643 ** CAPI3REF: Determine If An SQL Statement Is Complete
2645 ** These routines are useful during command-line input to determine if the
2646 ** currently entered text seems to form a complete SQL statement or
2647 ** if additional input is needed before sending the text into
2648 ** SQLite for parsing. ^These routines return 1 if the input string
2649 ** appears to be a complete SQL statement. ^A statement is judged to be
2650 ** complete if it ends with a semicolon token and is not a prefix of a
2651 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2652 ** string literals or quoted identifier names or comments are not
2653 ** independent tokens (they are part of the token in which they are
2654 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2655 ** and comments that follow the final semicolon are ignored.
2657 ** ^These routines return 0 if the statement is incomplete. ^If a
2658 ** memory allocation fails, then SQLITE_NOMEM is returned.
2660 ** ^These routines do not parse the SQL statements thus
2661 ** will not detect syntactically incorrect SQL.
2663 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2664 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2665 ** automatically by sqlite3_complete16(). If that initialization fails,
2666 ** then the return value from sqlite3_complete16() will be non-zero
2667 ** regardless of whether or not the input SQL is complete.)^
2669 ** The input to [sqlite3_complete()] must be a zero-terminated
2672 ** The input to [sqlite3_complete16()] must be a zero-terminated
2673 ** UTF-16 string in native byte order.
2675 SQLITE_API int sqlite3_complete(const char *sql);
2676 SQLITE_API int sqlite3_complete16(const void *sql);
2679 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2680 ** KEYWORDS: {busy-handler callback} {busy handler}
2683 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2684 ** that might be invoked with argument P whenever
2685 ** an attempt is made to access a database table associated with
2686 ** [database connection] D when another thread
2687 ** or process has the table locked.
2688 ** The sqlite3_busy_handler() interface is used to implement
2689 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2691 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2692 ** is returned immediately upon encountering the lock. ^If the busy callback
2693 ** is not NULL, then the callback might be invoked with two arguments.
2695 ** ^The first argument to the busy handler is a copy of the void* pointer which
2696 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2697 ** the busy handler callback is the number of times that the busy handler has
2698 ** been invoked previously for the same locking event. ^If the
2699 ** busy callback returns 0, then no additional attempts are made to
2700 ** access the database and [SQLITE_BUSY] is returned
2701 ** to the application.
2702 ** ^If the callback returns non-zero, then another attempt
2703 ** is made to access the database and the cycle repeats.
2705 ** The presence of a busy handler does not guarantee that it will be invoked
2706 ** when there is lock contention. ^If SQLite determines that invoking the busy
2707 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2708 ** to the application instead of invoking the
2710 ** Consider a scenario where one process is holding a read lock that
2711 ** it is trying to promote to a reserved lock and
2712 ** a second process is holding a reserved lock that it is trying
2713 ** to promote to an exclusive lock. The first process cannot proceed
2714 ** because it is blocked by the second and the second process cannot
2715 ** proceed because it is blocked by the first. If both processes
2716 ** invoke the busy handlers, neither will make any progress. Therefore,
2717 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2718 ** will induce the first process to release its read lock and allow
2719 ** the second process to proceed.
2721 ** ^The default busy callback is NULL.
2723 ** ^(There can only be a single busy handler defined for each
2724 ** [database connection]. Setting a new busy handler clears any
2725 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2726 ** or evaluating [PRAGMA busy_timeout=N] will change the
2727 ** busy handler and thus clear any previously set busy handler.
2729 ** The busy callback should not take any actions which modify the
2730 ** database connection that invoked the busy handler. In other words,
2731 ** the busy handler is not reentrant. Any such actions
2732 ** result in undefined behavior.
2734 ** A busy handler must not close the database connection
2735 ** or [prepared statement] that invoked the busy handler.
2737 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2740 ** CAPI3REF: Set A Busy Timeout
2743 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2744 ** for a specified amount of time when a table is locked. ^The handler
2745 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2746 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2747 ** the handler returns 0 which causes [sqlite3_step()] to return
2750 ** ^Calling this routine with an argument less than or equal to zero
2751 ** turns off all busy handlers.
2753 ** ^(There can only be a single busy handler for a particular
2754 ** [database connection] at any given moment. If another busy handler
2755 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2756 ** this routine, that other busy handler is cleared.)^
2758 ** See also: [PRAGMA busy_timeout]
2760 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2763 ** CAPI3REF: Convenience Routines For Running Queries
2766 ** This is a legacy interface that is preserved for backwards compatibility.
2767 ** Use of this interface is not recommended.
2769 ** Definition: A <b>result table</b> is memory data structure created by the
2770 ** [sqlite3_get_table()] interface. A result table records the
2771 ** complete query results from one or more queries.
2773 ** The table conceptually has a number of rows and columns. But
2774 ** these numbers are not part of the result table itself. These
2775 ** numbers are obtained separately. Let N be the number of rows
2776 ** and M be the number of columns.
2778 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2779 ** There are (N+1)*M elements in the array. The first M pointers point
2780 ** to zero-terminated strings that contain the names of the columns.
2781 ** The remaining entries all point to query results. NULL values result
2782 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2783 ** string representation as returned by [sqlite3_column_text()].
2785 ** A result table might consist of one or more memory allocations.
2786 ** It is not safe to pass a result table directly to [sqlite3_free()].
2787 ** A result table should be deallocated using [sqlite3_free_table()].
2789 ** ^(As an example of the result table format, suppose a query result
2792 ** <blockquote><pre>
2794 ** -----------------------
2798 ** </pre></blockquote>
2800 ** There are two columns (M==2) and three rows (N==3). Thus the
2801 ** result table has 8 entries. Suppose the result table is stored
2802 ** in an array named azResult. Then azResult holds this content:
2804 ** <blockquote><pre>
2805 ** azResult[0] = "Name";
2806 ** azResult[1] = "Age";
2807 ** azResult[2] = "Alice";
2808 ** azResult[3] = "43";
2809 ** azResult[4] = "Bob";
2810 ** azResult[5] = "28";
2811 ** azResult[6] = "Cindy";
2812 ** azResult[7] = "21";
2813 ** </pre></blockquote>)^
2815 ** ^The sqlite3_get_table() function evaluates one or more
2816 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2817 ** string of its 2nd parameter and returns a result table to the
2818 ** pointer given in its 3rd parameter.
2820 ** After the application has finished with the result from sqlite3_get_table(),
2821 ** it must pass the result table pointer to sqlite3_free_table() in order to
2822 ** release the memory that was malloced. Because of the way the
2823 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2824 ** function must not try to call [sqlite3_free()] directly. Only
2825 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2827 ** The sqlite3_get_table() interface is implemented as a wrapper around
2828 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2829 ** to any internal data structures of SQLite. It uses only the public
2830 ** interface defined here. As a consequence, errors that occur in the
2831 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2832 ** reflected in subsequent calls to [sqlite3_errcode()] or
2833 ** [sqlite3_errmsg()].
2835 SQLITE_API int sqlite3_get_table(
2836 sqlite3 *db, /* An open database */
2837 const char *zSql, /* SQL to be evaluated */
2838 char ***pazResult, /* Results of the query */
2839 int *pnRow, /* Number of result rows written here */
2840 int *pnColumn, /* Number of result columns written here */
2841 char **pzErrmsg /* Error msg written here */
2843 SQLITE_API void sqlite3_free_table(char **result);
2846 ** CAPI3REF: Formatted String Printing Functions
2848 ** These routines are work-alikes of the "printf()" family of functions
2849 ** from the standard C library.
2850 ** These routines understand most of the common formatting options from
2851 ** the standard library printf()
2852 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2853 ** See the [built-in printf()] documentation for details.
2855 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2856 ** results into memory obtained from [sqlite3_malloc64()].
2857 ** The strings returned by these two routines should be
2858 ** released by [sqlite3_free()]. ^Both routines return a
2859 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2860 ** memory to hold the resulting string.
2862 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2863 ** the standard C library. The result is written into the
2864 ** buffer supplied as the second parameter whose size is given by
2865 ** the first parameter. Note that the order of the
2866 ** first two parameters is reversed from snprintf().)^ This is an
2867 ** historical accident that cannot be fixed without breaking
2868 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2869 ** returns a pointer to its buffer instead of the number of
2870 ** characters actually written into the buffer.)^ We admit that
2871 ** the number of characters written would be a more useful return
2872 ** value but we cannot change the implementation of sqlite3_snprintf()
2873 ** now without breaking compatibility.
2875 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2876 ** guarantees that the buffer is always zero-terminated. ^The first
2877 ** parameter "n" is the total size of the buffer, including space for
2878 ** the zero terminator. So the longest string that can be completely
2879 ** written will be n-1 characters.
2881 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2883 ** See also: [built-in printf()], [printf() SQL function]
2885 SQLITE_API char *sqlite3_mprintf(const char*,...);
2886 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2887 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2888 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2891 ** CAPI3REF: Memory Allocation Subsystem
2893 ** The SQLite core uses these three routines for all of its own
2894 ** internal memory allocation needs. "Core" in the previous sentence
2895 ** does not include operating-system specific [VFS] implementation. The
2896 ** Windows VFS uses native malloc() and free() for some operations.
2898 ** ^The sqlite3_malloc() routine returns a pointer to a block
2899 ** of memory at least N bytes in length, where N is the parameter.
2900 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2901 ** memory, it returns a NULL pointer. ^If the parameter N to
2902 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2905 ** ^The sqlite3_malloc64(N) routine works just like
2906 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2907 ** of a signed 32-bit integer.
2909 ** ^Calling sqlite3_free() with a pointer previously returned
2910 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2911 ** that it might be reused. ^The sqlite3_free() routine is
2912 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2913 ** to sqlite3_free() is harmless. After being freed, memory
2914 ** should neither be read nor written. Even reading previously freed
2915 ** memory might result in a segmentation fault or other severe error.
2916 ** Memory corruption, a segmentation fault, or other severe error
2917 ** might result if sqlite3_free() is called with a non-NULL pointer that
2918 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2920 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
2921 ** prior memory allocation X to be at least N bytes.
2922 ** ^If the X parameter to sqlite3_realloc(X,N)
2923 ** is a NULL pointer then its behavior is identical to calling
2924 ** sqlite3_malloc(N).
2925 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2926 ** negative then the behavior is exactly the same as calling
2928 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2929 ** of at least N bytes in size or NULL if insufficient memory is available.
2930 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2931 ** of the prior allocation are copied into the beginning of buffer returned
2932 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
2933 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2934 ** prior allocation is not freed.
2936 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
2937 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2938 ** of a 32-bit signed integer.
2940 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2941 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2942 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2943 ** ^The value returned by sqlite3_msize(X) might be larger than the number
2944 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
2945 ** sqlite3_msize(X) returns zero. If X points to something that is not
2946 ** the beginning of memory allocation, or if it points to a formerly
2947 ** valid memory allocation that has now been freed, then the behavior
2948 ** of sqlite3_msize(X) is undefined and possibly harmful.
2950 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2951 ** sqlite3_malloc64(), and sqlite3_realloc64()
2952 ** is always aligned to at least an 8 byte boundary, or to a
2953 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2956 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2957 ** must be either NULL or else pointers obtained from a prior
2958 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2959 ** not yet been released.
2961 ** The application must not read or write any part of
2962 ** a block of memory after it has been released using
2963 ** [sqlite3_free()] or [sqlite3_realloc()].
2965 SQLITE_API void *sqlite3_malloc(int);
2966 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2967 SQLITE_API void *sqlite3_realloc(void*, int);
2968 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2969 SQLITE_API void sqlite3_free(void*);
2970 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2973 ** CAPI3REF: Memory Allocator Statistics
2975 ** SQLite provides these two interfaces for reporting on the status
2976 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2977 ** routines, which form the built-in memory allocation subsystem.
2979 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2980 ** of memory currently outstanding (malloced but not freed).
2981 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2982 ** value of [sqlite3_memory_used()] since the high-water mark
2983 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2984 ** [sqlite3_memory_highwater()] include any overhead
2985 ** added by SQLite in its implementation of [sqlite3_malloc()],
2986 ** but not overhead added by the any underlying system library
2987 ** routines that [sqlite3_malloc()] may call.
2989 ** ^The memory high-water mark is reset to the current value of
2990 ** [sqlite3_memory_used()] if and only if the parameter to
2991 ** [sqlite3_memory_highwater()] is true. ^The value returned
2992 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2993 ** prior to the reset.
2995 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2996 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2999 ** CAPI3REF: Pseudo-Random Number Generator
3001 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3002 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3003 ** already uses the largest possible [ROWID]. The PRNG is also used for
3004 ** the built-in random() and randomblob() SQL functions. This interface allows
3005 ** applications to access the same PRNG for other purposes.
3007 ** ^A call to this routine stores N bytes of randomness into buffer P.
3008 ** ^The P parameter can be a NULL pointer.
3010 ** ^If this routine has not been previously called or if the previous
3011 ** call had N less than one or a NULL pointer for P, then the PRNG is
3012 ** seeded using randomness obtained from the xRandomness method of
3013 ** the default [sqlite3_vfs] object.
3014 ** ^If the previous call to this routine had an N of 1 or more and a
3015 ** non-NULL P then the pseudo-randomness is generated
3016 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3019 SQLITE_API void sqlite3_randomness(int N, void *P);
3022 ** CAPI3REF: Compile-Time Authorization Callbacks
3024 ** KEYWORDS: {authorizer callback}
3026 ** ^This routine registers an authorizer callback with a particular
3027 ** [database connection], supplied in the first argument.
3028 ** ^The authorizer callback is invoked as SQL statements are being compiled
3029 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3030 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3031 ** and [sqlite3_prepare16_v3()]. ^At various
3032 ** points during the compilation process, as logic is being created
3033 ** to perform various actions, the authorizer callback is invoked to
3034 ** see if those actions are allowed. ^The authorizer callback should
3035 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3036 ** specific action but allow the SQL statement to continue to be
3037 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3038 ** rejected with an error. ^If the authorizer callback returns
3039 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3040 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3041 ** the authorizer will fail with an error message.
3043 ** When the callback returns [SQLITE_OK], that means the operation
3044 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3045 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3046 ** authorizer will fail with an error message explaining that
3047 ** access is denied.
3049 ** ^The first parameter to the authorizer callback is a copy of the third
3050 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3051 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3052 ** the particular action to be authorized. ^The third through sixth parameters
3053 ** to the callback are either NULL pointers or zero-terminated strings
3054 ** that contain additional details about the action to be authorized.
3055 ** Applications must always be prepared to encounter a NULL pointer in any
3056 ** of the third through the sixth parameters of the authorization callback.
3058 ** ^If the action code is [SQLITE_READ]
3059 ** and the callback returns [SQLITE_IGNORE] then the
3060 ** [prepared statement] statement is constructed to substitute
3061 ** a NULL value in place of the table column that would have
3062 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3063 ** return can be used to deny an untrusted user access to individual
3064 ** columns of a table.
3065 ** ^When a table is referenced by a [SELECT] but no column values are
3066 ** extracted from that table (for example in a query like
3067 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3068 ** is invoked once for that table with a column name that is an empty string.
3069 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3070 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3071 ** [truncate optimization] is disabled and all rows are deleted individually.
3073 ** An authorizer is used when [sqlite3_prepare | preparing]
3074 ** SQL statements from an untrusted source, to ensure that the SQL statements
3075 ** do not try to access data they are not allowed to see, or that they do not
3076 ** try to execute malicious statements that damage the database. For
3077 ** example, an application may allow a user to enter arbitrary
3078 ** SQL queries for evaluation by a database. But the application does
3079 ** not want the user to be able to make arbitrary changes to the
3080 ** database. An authorizer could then be put in place while the
3081 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3082 ** disallows everything except [SELECT] statements.
3084 ** Applications that need to process SQL from untrusted sources
3085 ** might also consider lowering resource limits using [sqlite3_limit()]
3086 ** and limiting database size using the [max_page_count] [PRAGMA]
3087 ** in addition to using an authorizer.
3089 ** ^(Only a single authorizer can be in place on a database connection
3090 ** at a time. Each call to sqlite3_set_authorizer overrides the
3091 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3092 ** The authorizer is disabled by default.
3094 ** The authorizer callback must not do anything that will modify
3095 ** the database connection that invoked the authorizer callback.
3096 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3097 ** database connections for the meaning of "modify" in this paragraph.
3099 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3100 ** statement might be re-prepared during [sqlite3_step()] due to a
3101 ** schema change. Hence, the application should ensure that the
3102 ** correct authorizer callback remains in place during the [sqlite3_step()].
3104 ** ^Note that the authorizer callback is invoked only during
3105 ** [sqlite3_prepare()] or its variants. Authorization is not
3106 ** performed during statement evaluation in [sqlite3_step()], unless
3107 ** as stated in the previous paragraph, sqlite3_step() invokes
3108 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3110 SQLITE_API int sqlite3_set_authorizer(
3112 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3117 ** CAPI3REF: Authorizer Return Codes
3119 ** The [sqlite3_set_authorizer | authorizer callback function] must
3120 ** return either [SQLITE_OK] or one of these two constants in order
3121 ** to signal SQLite whether or not the action is permitted. See the
3122 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3125 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3126 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3128 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3129 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3132 ** CAPI3REF: Authorizer Action Codes
3134 ** The [sqlite3_set_authorizer()] interface registers a callback function
3135 ** that is invoked to authorize certain SQL statement actions. The
3136 ** second parameter to the callback is an integer code that specifies
3137 ** what action is being authorized. These are the integer action codes that
3138 ** the authorizer callback may be passed.
3140 ** These action code values signify what kind of operation is to be
3141 ** authorized. The 3rd and 4th parameters to the authorization
3142 ** callback function will be parameters or NULL depending on which of these
3143 ** codes is used as the second parameter. ^(The 5th parameter to the
3144 ** authorizer callback is the name of the database ("main", "temp",
3145 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3146 ** is the name of the inner-most trigger or view that is responsible for
3147 ** the access attempt or NULL if this access attempt is directly from
3148 ** top-level SQL code.
3150 /******************************************* 3rd ************ 4th ***********/
3151 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3152 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3153 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3154 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3155 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3156 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3157 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3158 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3159 #define SQLITE_DELETE 9 /* Table Name NULL */
3160 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3161 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3162 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3163 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3164 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3165 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3166 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3167 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3168 #define SQLITE_INSERT 18 /* Table Name NULL */
3169 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3170 #define SQLITE_READ 20 /* Table Name Column Name */
3171 #define SQLITE_SELECT 21 /* NULL NULL */
3172 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3173 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3174 #define SQLITE_ATTACH 24 /* Filename NULL */
3175 #define SQLITE_DETACH 25 /* Database Name NULL */
3176 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3177 #define SQLITE_REINDEX 27 /* Index Name NULL */
3178 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3179 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3180 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3181 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3182 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3183 #define SQLITE_COPY 0 /* No longer used */
3184 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3187 ** CAPI3REF: Tracing And Profiling Functions
3190 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3191 ** instead of the routines described here.
3193 ** These routines register callback functions that can be used for
3194 ** tracing and profiling the execution of SQL statements.
3196 ** ^The callback function registered by sqlite3_trace() is invoked at
3197 ** various times when an SQL statement is being run by [sqlite3_step()].
3198 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3199 ** SQL statement text as the statement first begins executing.
3200 ** ^(Additional sqlite3_trace() callbacks might occur
3201 ** as each triggered subprogram is entered. The callbacks for triggers
3202 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3204 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3205 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3207 ** ^The callback function registered by sqlite3_profile() is invoked
3208 ** as each SQL statement finishes. ^The profile callback contains
3209 ** the original statement text and an estimate of wall-clock time
3210 ** of how long that statement took to run. ^The profile callback
3211 ** time is in units of nanoseconds, however the current implementation
3212 ** is only capable of millisecond resolution so the six least significant
3213 ** digits in the time are meaningless. Future versions of SQLite
3214 ** might provide greater resolution on the profiler callback. Invoking
3215 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3216 ** profile callback.
3218 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3219 void(*xTrace)(void*,const char*), void*);
3220 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3221 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3224 ** CAPI3REF: SQL Trace Event Codes
3225 ** KEYWORDS: SQLITE_TRACE
3227 ** These constants identify classes of events that can be monitored
3228 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3229 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3230 ** the following constants. ^The first argument to the trace callback
3231 ** is one of the following constants.
3233 ** New tracing constants may be added in future releases.
3235 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3236 ** ^The T argument is one of the integer type codes above.
3237 ** ^The C argument is a copy of the context pointer passed in as the
3238 ** fourth argument to [sqlite3_trace_v2()].
3239 ** The P and X arguments are pointers whose meanings depend on T.
3242 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3243 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3244 ** first begins running and possibly at other times during the
3245 ** execution of the prepared statement, such as at the start of each
3246 ** trigger subprogram. ^The P argument is a pointer to the
3247 ** [prepared statement]. ^The X argument is a pointer to a string which
3248 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3249 ** that indicates the invocation of a trigger. ^The callback can compute
3250 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3251 ** interface by using the X argument when X begins with "--" and invoking
3252 ** [sqlite3_expanded_sql(P)] otherwise.
3254 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3255 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3256 ** information as is provided by the [sqlite3_profile()] callback.
3257 ** ^The P argument is a pointer to the [prepared statement] and the
3258 ** X argument points to a 64-bit integer which is the estimated of
3259 ** the number of nanosecond that the prepared statement took to run.
3260 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3262 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3263 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3264 ** statement generates a single row of result.
3265 ** ^The P argument is a pointer to the [prepared statement] and the
3266 ** X argument is unused.
3268 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3269 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3270 ** connection closes.
3271 ** ^The P argument is a pointer to the [database connection] object
3272 ** and the X argument is unused.
3275 #define SQLITE_TRACE_STMT 0x01
3276 #define SQLITE_TRACE_PROFILE 0x02
3277 #define SQLITE_TRACE_ROW 0x04
3278 #define SQLITE_TRACE_CLOSE 0x08
3281 ** CAPI3REF: SQL Trace Hook
3284 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3285 ** function X against [database connection] D, using property mask M
3286 ** and context pointer P. ^If the X callback is
3287 ** NULL or if the M mask is zero, then tracing is disabled. The
3288 ** M argument should be the bitwise OR-ed combination of
3289 ** zero or more [SQLITE_TRACE] constants.
3291 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3292 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3294 ** ^The X callback is invoked whenever any of the events identified by
3295 ** mask M occur. ^The integer return value from the callback is currently
3296 ** ignored, though this may change in future releases. Callback
3297 ** implementations should return zero to ensure future compatibility.
3299 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3300 ** ^The T argument is one of the [SQLITE_TRACE]
3301 ** constants to indicate why the callback was invoked.
3302 ** ^The C argument is a copy of the context pointer.
3303 ** The P and X arguments are pointers whose meanings depend on T.
3305 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3306 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3309 SQLITE_API int sqlite3_trace_v2(
3312 int(*xCallback)(unsigned,void*,void*,void*),
3317 ** CAPI3REF: Query Progress Callbacks
3320 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3321 ** function X to be invoked periodically during long running calls to
3322 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3323 ** database connection D. An example use for this
3324 ** interface is to keep a GUI updated during a large query.
3326 ** ^The parameter P is passed through as the only parameter to the
3327 ** callback function X. ^The parameter N is the approximate number of
3328 ** [virtual machine instructions] that are evaluated between successive
3329 ** invocations of the callback X. ^If N is less than one then the progress
3330 ** handler is disabled.
3332 ** ^Only a single progress handler may be defined at one time per
3333 ** [database connection]; setting a new progress handler cancels the
3334 ** old one. ^Setting parameter X to NULL disables the progress handler.
3335 ** ^The progress handler is also disabled by setting N to a value less
3338 ** ^If the progress callback returns non-zero, the operation is
3339 ** interrupted. This feature can be used to implement a
3340 ** "Cancel" button on a GUI progress dialog box.
3342 ** The progress handler callback must not do anything that will modify
3343 ** the database connection that invoked the progress handler.
3344 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3345 ** database connections for the meaning of "modify" in this paragraph.
3348 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3351 ** CAPI3REF: Opening A New Database Connection
3352 ** CONSTRUCTOR: sqlite3
3354 ** ^These routines open an SQLite database file as specified by the
3355 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3356 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3357 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3358 ** returned in *ppDb, even if an error occurs. The only exception is that
3359 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3360 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3361 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3362 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3363 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3364 ** an English language description of the error following a failure of any
3365 ** of the sqlite3_open() routines.
3367 ** ^The default encoding will be UTF-8 for databases created using
3368 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3369 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3371 ** Whether or not an error occurs when it is opened, resources
3372 ** associated with the [database connection] handle should be released by
3373 ** passing it to [sqlite3_close()] when it is no longer required.
3375 ** The sqlite3_open_v2() interface works like sqlite3_open()
3376 ** except that it accepts two additional parameters for additional control
3377 ** over the new database connection. ^(The flags parameter to
3378 ** sqlite3_open_v2() must include, at a minimum, one of the following
3379 ** three flag combinations:)^
3382 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3383 ** <dd>The database is opened in read-only mode. If the database does not
3384 ** already exist, an error is returned.</dd>)^
3386 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3387 ** <dd>The database is opened for reading and writing if possible, or reading
3388 ** only if the file is write protected by the operating system. In either
3389 ** case the database must already exist, otherwise an error is returned.</dd>)^
3391 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3392 ** <dd>The database is opened for reading and writing, and is created if
3393 ** it does not already exist. This is the behavior that is always used for
3394 ** sqlite3_open() and sqlite3_open16().</dd>)^
3397 ** In addition to the required flags, the following optional flags are
3401 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3402 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3404 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3405 ** <dd>The database will be opened as an in-memory database. The database
3406 ** is named by the "filename" argument for the purposes of cache-sharing,
3407 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3410 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3411 ** <dd>The new database connection will use the "multi-thread"
3412 ** [threading mode].)^ This means that separate threads are allowed
3413 ** to use SQLite at the same time, as long as each thread is using
3414 ** a different [database connection].
3416 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3417 ** <dd>The new database connection will use the "serialized"
3418 ** [threading mode].)^ This means the multiple threads can safely
3419 ** attempt to use the same database connection at the same time.
3420 ** (Mutexes will block any actual concurrency, but in this mode
3421 ** there is no harm in trying.)
3423 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3424 ** <dd>The database is opened [shared cache] enabled, overriding
3425 ** the default shared cache setting provided by
3426 ** [sqlite3_enable_shared_cache()].)^
3428 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3429 ** <dd>The database is opened [shared cache] disabled, overriding
3430 ** the default shared cache setting provided by
3431 ** [sqlite3_enable_shared_cache()].)^
3433 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3434 ** <dd>The database connection comes up in "extended result code mode".
3435 ** In other words, the database behaves has if
3436 ** [sqlite3_extended_result_codes(db,1)] where called on the database
3437 ** connection as soon as the connection is created. In addition to setting
3438 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3439 ** to return an extended result code.</dd>
3441 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3442 ** <dd>The database filename is not allowed to be a symbolic link</dd>
3445 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3446 ** required combinations shown above optionally combined with other
3447 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3448 ** then the behavior is undefined. Historic versions of SQLite
3449 ** have silently ignored surplus bits in the flags parameter to
3450 ** sqlite3_open_v2(), however that behavior might not be carried through
3451 ** into future versions of SQLite and so applications should not rely
3452 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3453 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3454 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3455 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3456 ** by sqlite3_open_v2().
3458 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3459 ** [sqlite3_vfs] object that defines the operating system interface that
3460 ** the new database connection should use. ^If the fourth parameter is
3461 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3463 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3464 ** is created for the connection. ^This in-memory database will vanish when
3465 ** the database connection is closed. Future versions of SQLite might
3466 ** make use of additional special filenames that begin with the ":" character.
3467 ** It is recommended that when a database filename actually does begin with
3468 ** a ":" character you should prefix the filename with a pathname such as
3469 ** "./" to avoid ambiguity.
3471 ** ^If the filename is an empty string, then a private, temporary
3472 ** on-disk database will be created. ^This private database will be
3473 ** automatically deleted as soon as the database connection is closed.
3475 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3477 ** ^If [URI filename] interpretation is enabled, and the filename argument
3478 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3479 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3480 ** set in the third argument to sqlite3_open_v2(), or if it has
3481 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3482 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3483 ** URI filename interpretation is turned off
3484 ** by default, but future releases of SQLite might enable URI filename
3485 ** interpretation by default. See "[URI filenames]" for additional
3488 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3489 ** authority, then it must be either an empty string or the string
3490 ** "localhost". ^If the authority is not an empty string or "localhost", an
3491 ** error is returned to the caller. ^The fragment component of a URI, if
3492 ** present, is ignored.
3494 ** ^SQLite uses the path component of the URI as the name of the disk file
3495 ** which contains the database. ^If the path begins with a '/' character,
3496 ** then it is interpreted as an absolute path. ^If the path does not begin
3497 ** with a '/' (meaning that the authority section is omitted from the URI)
3498 ** then the path is interpreted as a relative path.
3499 ** ^(On windows, the first component of an absolute path
3500 ** is a drive specification (e.g. "C:").)^
3502 ** [[core URI query parameters]]
3503 ** The query component of a URI may contain parameters that are interpreted
3504 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3505 ** SQLite and its built-in [VFSes] interpret the
3506 ** following query parameters:
3509 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3510 ** a VFS object that provides the operating system interface that should
3511 ** be used to access the database file on disk. ^If this option is set to
3512 ** an empty string the default VFS object is used. ^Specifying an unknown
3513 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3514 ** present, then the VFS specified by the option takes precedence over
3515 ** the value passed as the fourth parameter to sqlite3_open_v2().
3517 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3518 ** "rwc", or "memory". Attempting to set it to any other value is
3520 ** ^If "ro" is specified, then the database is opened for read-only
3521 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3522 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3523 ** "rw", then the database is opened for read-write (but not create)
3524 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3525 ** been set. ^Value "rwc" is equivalent to setting both
3526 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3527 ** set to "memory" then a pure [in-memory database] that never reads
3528 ** or writes from disk is used. ^It is an error to specify a value for
3529 ** the mode parameter that is less restrictive than that specified by
3530 ** the flags passed in the third parameter to sqlite3_open_v2().
3532 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3533 ** "private". ^Setting it to "shared" is equivalent to setting the
3534 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3535 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3536 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3537 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3538 ** a URI filename, its value overrides any behavior requested by setting
3539 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3541 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3542 ** [powersafe overwrite] property does or does not apply to the
3543 ** storage media on which the database file resides.
3545 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3546 ** which if set disables file locking in rollback journal modes. This
3547 ** is useful for accessing a database on a filesystem that does not
3548 ** support locking. Caution: Database corruption might result if two
3549 ** or more processes write to the same database and any one of those
3550 ** processes uses nolock=1.
3552 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3553 ** parameter that indicates that the database file is stored on
3554 ** read-only media. ^When immutable is set, SQLite assumes that the
3555 ** database file cannot be changed, even by a process with higher
3556 ** privilege, and so the database is opened read-only and all locking
3557 ** and change detection is disabled. Caution: Setting the immutable
3558 ** property on a database file that does in fact change can result
3559 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3560 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3564 ** ^Specifying an unknown parameter in the query component of a URI is not an
3565 ** error. Future versions of SQLite might understand additional query
3566 ** parameters. See "[query parameters with special meaning to SQLite]" for
3567 ** additional information.
3569 ** [[URI filename examples]] <h3>URI filename examples</h3>
3571 ** <table border="1" align=center cellpadding=5>
3572 ** <tr><th> URI filenames <th> Results
3573 ** <tr><td> file:data.db <td>
3574 ** Open the file "data.db" in the current directory.
3575 ** <tr><td> file:/home/fred/data.db<br>
3576 ** file:///home/fred/data.db <br>
3577 ** file://localhost/home/fred/data.db <br> <td>
3578 ** Open the database file "/home/fred/data.db".
3579 ** <tr><td> file://darkstar/home/fred/data.db <td>
3580 ** An error. "darkstar" is not a recognized authority.
3581 ** <tr><td style="white-space:nowrap">
3582 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3583 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3584 ** C:. Note that the %20 escaping in this example is not strictly
3585 ** necessary - space characters can be used literally
3586 ** in URI filenames.
3587 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3588 ** Open file "data.db" in the current directory for read-only access.
3589 ** Regardless of whether or not shared-cache mode is enabled by
3590 ** default, use a private cache.
3591 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3592 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3593 ** that uses dot-files in place of posix advisory locking.
3594 ** <tr><td> file:data.db?mode=readonly <td>
3595 ** An error. "readonly" is not a valid option for the "mode" parameter.
3596 ** Use "ro" instead: "file:data.db?mode=ro".
3599 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3600 ** query components of a URI. A hexadecimal escape sequence consists of a
3601 ** percent sign - "%" - followed by exactly two hexadecimal digits
3602 ** specifying an octet value. ^Before the path or query components of a
3603 ** URI filename are interpreted, they are encoded using UTF-8 and all
3604 ** hexadecimal escape sequences replaced by a single byte containing the
3605 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3606 ** the results are undefined.
3608 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3609 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3610 ** codepage is currently defined. Filenames containing international
3611 ** characters must be converted to UTF-8 prior to passing them into
3612 ** sqlite3_open() or sqlite3_open_v2().
3614 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3615 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3616 ** features that require the use of temporary files may fail.
3618 ** See also: [sqlite3_temp_directory]
3620 SQLITE_API int sqlite3_open(
3621 const char *filename, /* Database filename (UTF-8) */
3622 sqlite3 **ppDb /* OUT: SQLite db handle */
3624 SQLITE_API int sqlite3_open16(
3625 const void *filename, /* Database filename (UTF-16) */
3626 sqlite3 **ppDb /* OUT: SQLite db handle */
3628 SQLITE_API int sqlite3_open_v2(
3629 const char *filename, /* Database filename (UTF-8) */
3630 sqlite3 **ppDb, /* OUT: SQLite db handle */
3631 int flags, /* Flags */
3632 const char *zVfs /* Name of VFS module to use */
3636 ** CAPI3REF: Obtain Values For URI Parameters
3638 ** These are utility routines, useful to [VFS|custom VFS implementations],
3639 ** that check if a database file was a URI that contained a specific query
3640 ** parameter, and if so obtains the value of that query parameter.
3642 ** The first parameter to these interfaces (hereafter referred to
3643 ** as F) must be one of:
3645 ** <li> A database filename pointer created by the SQLite core and
3646 ** passed into the xOpen() method of a VFS implemention, or
3647 ** <li> A filename obtained from [sqlite3_db_filename()], or
3648 ** <li> A new filename constructed using [sqlite3_create_filename()].
3650 ** If the F parameter is not one of the above, then the behavior is
3651 ** undefined and probably undesirable. Older versions of SQLite were
3652 ** more tolerant of invalid F parameters than newer versions.
3654 ** If F is a suitable filename (as described in the previous paragraph)
3655 ** and if P is the name of the query parameter, then
3656 ** sqlite3_uri_parameter(F,P) returns the value of the P
3657 ** parameter if it exists or a NULL pointer if P does not appear as a
3658 ** query parameter on F. If P is a query parameter of F and it
3659 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3660 ** a pointer to an empty string.
3662 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3663 ** parameter and returns true (1) or false (0) according to the value
3664 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3665 ** value of query parameter P is one of "yes", "true", or "on" in any
3666 ** case or if the value begins with a non-zero number. The
3667 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3668 ** query parameter P is one of "no", "false", or "off" in any case or
3669 ** if the value begins with a numeric zero. If P is not a query
3670 ** parameter on F or if the value of P does not match any of the
3671 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3673 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3674 ** 64-bit signed integer and returns that integer, or D if P does not
3675 ** exist. If the value of P is something other than an integer, then
3676 ** zero is returned.
3678 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3679 ** the value) of the N-th query parameter for filename F, or a NULL
3680 ** pointer if N is less than zero or greater than the number of query
3681 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3682 ** the name of the first query parameter, 1 for the second parameter, and
3685 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3686 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3687 ** is not a database file pathname pointer that the SQLite core passed
3688 ** into the xOpen VFS method, then the behavior of this routine is undefined
3689 ** and probably undesirable.
3691 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3692 ** parameter can also be the name of a rollback journal file or WAL file
3693 ** in addition to the main database file. Prior to version 3.31.0, these
3694 ** routines would only work if F was the name of the main database file.
3695 ** When the F parameter is the name of the rollback journal or WAL file,
3696 ** it has access to all the same query parameters as were found on the
3697 ** main database file.
3699 ** See the [URI filename] documentation for additional information.
3701 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3702 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3703 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3704 SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
3707 ** CAPI3REF: Translate filenames
3709 ** These routines are available to [VFS|custom VFS implementations] for
3710 ** translating filenames between the main database file, the journal file,
3711 ** and the WAL file.
3713 ** If F is the name of an sqlite database file, journal file, or WAL file
3714 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3715 ** returns the name of the corresponding database file.
3717 ** If F is the name of an sqlite database file, journal file, or WAL file
3718 ** passed by the SQLite core into the VFS, or if F is a database filename
3719 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3720 ** returns the name of the corresponding rollback journal file.
3722 ** If F is the name of an sqlite database file, journal file, or WAL file
3723 ** that was passed by the SQLite core into the VFS, or if F is a database
3724 ** filename obtained from [sqlite3_db_filename()], then
3725 ** sqlite3_filename_wal(F) returns the name of the corresponding
3728 ** In all of the above, if F is not the name of a database, journal or WAL
3729 ** filename passed into the VFS from the SQLite core and F is not the
3730 ** return value from [sqlite3_db_filename()], then the result is
3731 ** undefined and is likely a memory access violation.
3733 SQLITE_API const char *sqlite3_filename_database(const char*);
3734 SQLITE_API const char *sqlite3_filename_journal(const char*);
3735 SQLITE_API const char *sqlite3_filename_wal(const char*);
3738 ** CAPI3REF: Database File Corresponding To A Journal
3740 ** ^If X is the name of a rollback or WAL-mode journal file that is
3741 ** passed into the xOpen method of [sqlite3_vfs], then
3742 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3743 ** object that represents the main database file.
3745 ** This routine is intended for use in custom [VFS] implementations
3746 ** only. It is not a general-purpose interface.
3747 ** The argument sqlite3_file_object(X) must be a filename pointer that
3748 ** has been passed into [sqlite3_vfs].xOpen method where the
3749 ** flags parameter to xOpen contains one of the bits
3750 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3751 ** of this routine results in undefined and probably undesirable
3754 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3757 ** CAPI3REF: Create and Destroy VFS Filenames
3759 ** These interfces are provided for use by [VFS shim] implementations and
3760 ** are not useful outside of that context.
3762 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3763 ** database filename D with corresponding journal file J and WAL file W and
3764 ** with N URI parameters key/values pairs in the array P. The result from
3765 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3766 ** is safe to pass to routines like:
3768 ** <li> [sqlite3_uri_parameter()],
3769 ** <li> [sqlite3_uri_boolean()],
3770 ** <li> [sqlite3_uri_int64()],
3771 ** <li> [sqlite3_uri_key()],
3772 ** <li> [sqlite3_filename_database()],
3773 ** <li> [sqlite3_filename_journal()], or
3774 ** <li> [sqlite3_filename_wal()].
3776 ** If a memory allocation error occurs, sqlite3_create_filename() might
3777 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3778 ** must be released by a corresponding call to sqlite3_free_filename(Y).
3780 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3781 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3782 ** to a key and value for a query parameter. The P parameter may be a NULL
3783 ** pointer if N is zero. None of the 2*N pointers in the P array may be
3784 ** NULL pointers and key pointers should not be empty strings.
3785 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3786 ** be NULL pointers, though they can be empty strings.
3788 ** The sqlite3_free_filename(Y) routine releases a memory allocation
3789 ** previously obtained from sqlite3_create_filename(). Invoking
3790 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3792 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
3793 ** than a NULL pointer or a pointer previously acquired from
3794 ** sqlite3_create_filename(), then bad things such as heap
3795 ** corruption or segfaults may occur. The value Y should not be
3796 ** used again after sqlite3_free_filename(Y) has been called. This means
3797 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3798 ** then the corresponding [sqlite3_module.xClose() method should also be
3799 ** invoked prior to calling sqlite3_free_filename(Y).
3801 SQLITE_API char *sqlite3_create_filename(
3802 const char *zDatabase,
3803 const char *zJournal,
3806 const char **azParam
3808 SQLITE_API void sqlite3_free_filename(char*);
3811 ** CAPI3REF: Error Codes And Messages
3814 ** ^If the most recent sqlite3_* API call associated with
3815 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3816 ** returns the numeric [result code] or [extended result code] for that
3818 ** ^The sqlite3_extended_errcode()
3819 ** interface is the same except that it always returns the
3820 ** [extended result code] even when extended result codes are
3823 ** The values returned by sqlite3_errcode() and/or
3824 ** sqlite3_extended_errcode() might change with each API call.
3825 ** Except, there are some interfaces that are guaranteed to never
3826 ** change the value of the error code. The error-code preserving
3830 ** <li> sqlite3_errcode()
3831 ** <li> sqlite3_extended_errcode()
3832 ** <li> sqlite3_errmsg()
3833 ** <li> sqlite3_errmsg16()
3836 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3837 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3838 ** ^(Memory to hold the error message string is managed internally.
3839 ** The application does not need to worry about freeing the result.
3840 ** However, the error string might be overwritten or deallocated by
3841 ** subsequent calls to other SQLite interface functions.)^
3843 ** ^The sqlite3_errstr() interface returns the English-language text
3844 ** that describes the [result code], as UTF-8.
3845 ** ^(Memory to hold the error message string is managed internally
3846 ** and must not be freed by the application)^.
3848 ** When the serialized [threading mode] is in use, it might be the
3849 ** case that a second error occurs on a separate thread in between
3850 ** the time of the first error and the call to these interfaces.
3851 ** When that happens, the second error will be reported since these
3852 ** interfaces always report the most recent result. To avoid
3853 ** this, each thread can obtain exclusive use of the [database connection] D
3854 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3855 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3856 ** all calls to the interfaces listed here are completed.
3858 ** If an interface fails with SQLITE_MISUSE, that means the interface
3859 ** was invoked incorrectly by the application. In that case, the
3860 ** error code and message may or may not be set.
3862 SQLITE_API int sqlite3_errcode(sqlite3 *db);
3863 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3864 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3865 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3866 SQLITE_API const char *sqlite3_errstr(int);
3869 ** CAPI3REF: Prepared Statement Object
3870 ** KEYWORDS: {prepared statement} {prepared statements}
3872 ** An instance of this object represents a single SQL statement that
3873 ** has been compiled into binary form and is ready to be evaluated.
3875 ** Think of each SQL statement as a separate computer program. The
3876 ** original SQL text is source code. A prepared statement object
3877 ** is the compiled object code. All SQL must be converted into a
3878 ** prepared statement before it can be run.
3880 ** The life-cycle of a prepared statement object usually goes like this:
3883 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3884 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
3886 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3887 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3888 ** to step 2. Do this zero or more times.
3889 ** <li> Destroy the object using [sqlite3_finalize()].
3892 typedef struct sqlite3_stmt sqlite3_stmt;
3895 ** CAPI3REF: Run-time Limits
3898 ** ^(This interface allows the size of various constructs to be limited
3899 ** on a connection by connection basis. The first parameter is the
3900 ** [database connection] whose limit is to be set or queried. The
3901 ** second parameter is one of the [limit categories] that define a
3902 ** class of constructs to be size limited. The third parameter is the
3903 ** new limit for that construct.)^
3905 ** ^If the new limit is a negative number, the limit is unchanged.
3906 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3907 ** [limits | hard upper bound]
3908 ** set at compile-time by a C preprocessor macro called
3909 ** [limits | SQLITE_MAX_<i>NAME</i>].
3910 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3911 ** ^Attempts to increase a limit above its hard upper bound are
3912 ** silently truncated to the hard upper bound.
3914 ** ^Regardless of whether or not the limit was changed, the
3915 ** [sqlite3_limit()] interface returns the prior value of the limit.
3916 ** ^Hence, to find the current value of a limit without changing it,
3917 ** simply invoke this interface with the third parameter set to -1.
3919 ** Run-time limits are intended for use in applications that manage
3920 ** both their own internal database and also databases that are controlled
3921 ** by untrusted external sources. An example application might be a
3922 ** web browser that has its own databases for storing history and
3923 ** separate databases controlled by JavaScript applications downloaded
3924 ** off the Internet. The internal databases can be given the
3925 ** large, default limits. Databases managed by external sources can
3926 ** be given much smaller limits designed to prevent a denial of service
3927 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3928 ** interface to further control untrusted SQL. The size of the database
3929 ** created by an untrusted script can be contained using the
3930 ** [max_page_count] [PRAGMA].
3932 ** New run-time limit categories may be added in future releases.
3934 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3937 ** CAPI3REF: Run-Time Limit Categories
3938 ** KEYWORDS: {limit category} {*limit categories}
3940 ** These constants define various performance limits
3941 ** that can be lowered at run-time using [sqlite3_limit()].
3942 ** The synopsis of the meanings of the various limits is shown below.
3943 ** Additional information is available at [limits | Limits in SQLite].
3946 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3947 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3949 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3950 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3952 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3953 ** <dd>The maximum number of columns in a table definition or in the
3954 ** result set of a [SELECT] or the maximum number of columns in an index
3955 ** or in an ORDER BY or GROUP BY clause.</dd>)^
3957 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3958 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3960 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3961 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3963 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3964 ** <dd>The maximum number of instructions in a virtual machine program
3965 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3966 ** the equivalent tries to allocate space for more than this many opcodes
3967 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3969 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3970 ** <dd>The maximum number of arguments on a function.</dd>)^
3972 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3973 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3975 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3976 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3977 ** <dd>The maximum length of the pattern argument to the [LIKE] or
3978 ** [GLOB] operators.</dd>)^
3980 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3981 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3982 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3984 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3985 ** <dd>The maximum depth of recursion for triggers.</dd>)^
3987 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3988 ** <dd>The maximum number of auxiliary worker threads that a single
3989 ** [prepared statement] may start.</dd>)^
3992 #define SQLITE_LIMIT_LENGTH 0
3993 #define SQLITE_LIMIT_SQL_LENGTH 1
3994 #define SQLITE_LIMIT_COLUMN 2
3995 #define SQLITE_LIMIT_EXPR_DEPTH 3
3996 #define SQLITE_LIMIT_COMPOUND_SELECT 4
3997 #define SQLITE_LIMIT_VDBE_OP 5
3998 #define SQLITE_LIMIT_FUNCTION_ARG 6
3999 #define SQLITE_LIMIT_ATTACHED 7
4000 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4001 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4002 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4003 #define SQLITE_LIMIT_WORKER_THREADS 11
4006 ** CAPI3REF: Prepare Flags
4008 ** These constants define various flags that can be passed into
4009 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4010 ** [sqlite3_prepare16_v3()] interfaces.
4012 ** New flags may be added in future releases of SQLite.
4015 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4016 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4017 ** that the prepared statement will be retained for a long time and
4018 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4019 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4020 ** be used just once or at most a few times and then destroyed using
4021 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4022 ** on this hint by avoiding the use of [lookaside memory] so as not to
4023 ** deplete the limited store of lookaside memory. Future versions of
4024 ** SQLite may act on this hint differently.
4026 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4027 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4028 ** to be required for any prepared statement that wanted to use the
4029 ** [sqlite3_normalized_sql()] interface. However, the
4030 ** [sqlite3_normalized_sql()] interface is now available to all
4031 ** prepared statements, regardless of whether or not they use this
4034 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4035 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4036 ** to return an error (error code SQLITE_ERROR) if the statement uses
4037 ** any virtual tables.
4040 #define SQLITE_PREPARE_PERSISTENT 0x01
4041 #define SQLITE_PREPARE_NORMALIZE 0x02
4042 #define SQLITE_PREPARE_NO_VTAB 0x04
4045 ** CAPI3REF: Compiling An SQL Statement
4046 ** KEYWORDS: {SQL statement compiler}
4048 ** CONSTRUCTOR: sqlite3_stmt
4050 ** To execute an SQL statement, it must first be compiled into a byte-code
4051 ** program using one of these routines. Or, in other words, these routines
4052 ** are constructors for the [prepared statement] object.
4054 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4055 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4056 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4057 ** for special purposes.
4059 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4060 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4061 ** as a convenience. The UTF-16 interfaces work by converting the
4062 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4064 ** The first argument, "db", is a [database connection] obtained from a
4065 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4066 ** [sqlite3_open16()]. The database connection must not have been closed.
4068 ** The second argument, "zSql", is the statement to be compiled, encoded
4069 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4070 ** and sqlite3_prepare_v3()
4071 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4072 ** and sqlite3_prepare16_v3() use UTF-16.
4074 ** ^If the nByte argument is negative, then zSql is read up to the
4075 ** first zero terminator. ^If nByte is positive, then it is the
4076 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
4077 ** statement is generated.
4078 ** If the caller knows that the supplied string is nul-terminated, then
4079 ** there is a small performance advantage to passing an nByte parameter that
4080 ** is the number of bytes in the input string <i>including</i>
4081 ** the nul-terminator.
4083 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4084 ** past the end of the first SQL statement in zSql. These routines only
4085 ** compile the first statement in zSql, so *pzTail is left pointing to
4086 ** what remains uncompiled.
4088 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4089 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4090 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4091 ** string or a comment) then *ppStmt is set to NULL.
4092 ** The calling procedure is responsible for deleting the compiled
4093 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4094 ** ppStmt may not be NULL.
4096 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4097 ** otherwise an [error code] is returned.
4099 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4100 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4101 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4102 ** are retained for backwards compatibility, but their use is discouraged.
4103 ** ^In the "vX" interfaces, the prepared statement
4104 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4105 ** original SQL text. This causes the [sqlite3_step()] interface to
4106 ** behave differently in three ways:
4110 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4111 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4112 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4113 ** retries will occur before sqlite3_step() gives up and returns an error.
4117 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4118 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4119 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4120 ** and the application would have to make a second call to [sqlite3_reset()]
4121 ** in order to find the underlying cause of the problem. With the "v2" prepare
4122 ** interfaces, the underlying reason for the error is returned immediately.
4126 ** ^If the specific value bound to a [parameter | host parameter] in the
4127 ** WHERE clause might influence the choice of query plan for a statement,
4128 ** then the statement will be automatically recompiled, as if there had been
4129 ** a schema change, on the first [sqlite3_step()] call following any change
4130 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4131 ** ^The specific value of a WHERE-clause [parameter] might influence the
4132 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4133 ** or [GLOB] operator or if the parameter is compared to an indexed column
4134 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4138 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4139 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4140 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4141 ** sqlite3_prepare_v2() interface works exactly the same as
4142 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4144 SQLITE_API int sqlite3_prepare(
4145 sqlite3 *db, /* Database handle */
4146 const char *zSql, /* SQL statement, UTF-8 encoded */
4147 int nByte, /* Maximum length of zSql in bytes. */
4148 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4149 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4151 SQLITE_API int sqlite3_prepare_v2(
4152 sqlite3 *db, /* Database handle */
4153 const char *zSql, /* SQL statement, UTF-8 encoded */
4154 int nByte, /* Maximum length of zSql in bytes. */
4155 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4156 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4158 SQLITE_API int sqlite3_prepare_v3(
4159 sqlite3 *db, /* Database handle */
4160 const char *zSql, /* SQL statement, UTF-8 encoded */
4161 int nByte, /* Maximum length of zSql in bytes. */
4162 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4163 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4164 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4166 SQLITE_API int sqlite3_prepare16(
4167 sqlite3 *db, /* Database handle */
4168 const void *zSql, /* SQL statement, UTF-16 encoded */
4169 int nByte, /* Maximum length of zSql in bytes. */
4170 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4171 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4173 SQLITE_API int sqlite3_prepare16_v2(
4174 sqlite3 *db, /* Database handle */
4175 const void *zSql, /* SQL statement, UTF-16 encoded */
4176 int nByte, /* Maximum length of zSql in bytes. */
4177 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4178 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4180 SQLITE_API int sqlite3_prepare16_v3(
4181 sqlite3 *db, /* Database handle */
4182 const void *zSql, /* SQL statement, UTF-16 encoded */
4183 int nByte, /* Maximum length of zSql in bytes. */
4184 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4185 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4186 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4190 ** CAPI3REF: Retrieving Statement SQL
4191 ** METHOD: sqlite3_stmt
4193 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4194 ** SQL text used to create [prepared statement] P if P was
4195 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4196 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4197 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4198 ** string containing the SQL text of prepared statement P with
4199 ** [bound parameters] expanded.
4200 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4201 ** string containing the normalized SQL text of prepared statement P. The
4202 ** semantics used to normalize a SQL statement are unspecified and subject
4203 ** to change. At a minimum, literal values will be replaced with suitable
4206 ** ^(For example, if a prepared statement is created using the SQL
4207 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4208 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4209 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4210 ** will return "SELECT 2345,NULL".)^
4212 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4213 ** is available to hold the result, or if the result would exceed the
4214 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4216 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4217 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4218 ** option causes sqlite3_expanded_sql() to always return NULL.
4220 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4221 ** are managed by SQLite and are automatically freed when the prepared
4222 ** statement is finalized.
4223 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4224 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4225 ** by passing it to [sqlite3_free()].
4227 ** ^The sqlite3_normalized_sql() interface is only available if
4228 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4230 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4231 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4232 #ifdef SQLITE_ENABLE_NORMALIZE
4233 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4237 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4238 ** METHOD: sqlite3_stmt
4240 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4241 ** and only if the [prepared statement] X makes no direct changes to
4242 ** the content of the database file.
4244 ** Note that [application-defined SQL functions] or
4245 ** [virtual tables] might change the database indirectly as a side effect.
4246 ** ^(For example, if an application defines a function "eval()" that
4247 ** calls [sqlite3_exec()], then the following SQL statement would
4248 ** change the database file through side-effects:
4250 ** <blockquote><pre>
4251 ** SELECT eval('DELETE FROM t1') FROM t2;
4252 ** </pre></blockquote>
4254 ** But because the [SELECT] statement does not change the database file
4255 ** directly, sqlite3_stmt_readonly() would still return true.)^
4257 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4258 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4259 ** since the statements themselves do not actually modify the database but
4260 ** rather they control the timing of when other statements modify the
4261 ** database. ^The [ATTACH] and [DETACH] statements also cause
4262 ** sqlite3_stmt_readonly() to return true since, while those statements
4263 ** change the configuration of a database connection, they do not make
4264 ** changes to the content of the database files on disk.
4265 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4266 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4267 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4268 ** sqlite3_stmt_readonly() returns false for those commands.
4270 ** ^This routine returns false if there is any possibility that the
4271 ** statement might change the database file. ^A false return does
4272 ** not guarantee that the statement will change the database file.
4273 ** ^For example, an UPDATE statement might have a WHERE clause that
4274 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4275 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4276 ** read-only no-op if the table already exists, but
4277 ** sqlite3_stmt_readonly() still returns false for such a statement.
4279 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4282 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4283 ** METHOD: sqlite3_stmt
4285 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4286 ** prepared statement S is an EXPLAIN statement, or 2 if the
4287 ** statement S is an EXPLAIN QUERY PLAN.
4288 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4289 ** an ordinary statement or a NULL pointer.
4291 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4294 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4295 ** METHOD: sqlite3_stmt
4297 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4298 ** [prepared statement] S has been stepped at least once using
4299 ** [sqlite3_step(S)] but has neither run to completion (returned
4300 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4301 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4302 ** interface returns false if S is a NULL pointer. If S is not a
4303 ** NULL pointer and is not a pointer to a valid [prepared statement]
4304 ** object, then the behavior is undefined and probably undesirable.
4306 ** This interface can be used in combination [sqlite3_next_stmt()]
4307 ** to locate all prepared statements associated with a database
4308 ** connection that are in need of being reset. This can be used,
4309 ** for example, in diagnostic routines to search for prepared
4310 ** statements that are holding a transaction open.
4312 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4315 ** CAPI3REF: Dynamically Typed Value Object
4316 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4318 ** SQLite uses the sqlite3_value object to represent all values
4319 ** that can be stored in a database table. SQLite uses dynamic typing
4320 ** for the values it stores. ^Values stored in sqlite3_value objects
4321 ** can be integers, floating point values, strings, BLOBs, or NULL.
4323 ** An sqlite3_value object may be either "protected" or "unprotected".
4324 ** Some interfaces require a protected sqlite3_value. Other interfaces
4325 ** will accept either a protected or an unprotected sqlite3_value.
4326 ** Every interface that accepts sqlite3_value arguments specifies
4327 ** whether or not it requires a protected sqlite3_value. The
4328 ** [sqlite3_value_dup()] interface can be used to construct a new
4329 ** protected sqlite3_value from an unprotected sqlite3_value.
4331 ** The terms "protected" and "unprotected" refer to whether or not
4332 ** a mutex is held. An internal mutex is held for a protected
4333 ** sqlite3_value object but no mutex is held for an unprotected
4334 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4335 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4336 ** or if SQLite is run in one of reduced mutex modes
4337 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4338 ** then there is no distinction between protected and unprotected
4339 ** sqlite3_value objects and they can be used interchangeably. However,
4340 ** for maximum code portability it is recommended that applications
4341 ** still make the distinction between protected and unprotected
4342 ** sqlite3_value objects even when not strictly required.
4344 ** ^The sqlite3_value objects that are passed as parameters into the
4345 ** implementation of [application-defined SQL functions] are protected.
4346 ** ^The sqlite3_value object returned by
4347 ** [sqlite3_column_value()] is unprotected.
4348 ** Unprotected sqlite3_value objects may only be used as arguments
4349 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4350 ** [sqlite3_value_dup()].
4351 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4352 ** interfaces require protected sqlite3_value objects.
4354 typedef struct sqlite3_value sqlite3_value;
4357 ** CAPI3REF: SQL Function Context Object
4359 ** The context in which an SQL function executes is stored in an
4360 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4361 ** is always first parameter to [application-defined SQL functions].
4362 ** The application-defined SQL function implementation will pass this
4363 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4364 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4365 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4366 ** and/or [sqlite3_set_auxdata()].
4368 typedef struct sqlite3_context sqlite3_context;
4371 ** CAPI3REF: Binding Values To Prepared Statements
4372 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4373 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4374 ** METHOD: sqlite3_stmt
4376 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4377 ** literals may be replaced by a [parameter] that matches one of following
4388 ** In the templates above, NNN represents an integer literal,
4389 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4390 ** parameters (also called "host parameter names" or "SQL parameters")
4391 ** can be set using the sqlite3_bind_*() routines defined here.
4393 ** ^The first argument to the sqlite3_bind_*() routines is always
4394 ** a pointer to the [sqlite3_stmt] object returned from
4395 ** [sqlite3_prepare_v2()] or its variants.
4397 ** ^The second argument is the index of the SQL parameter to be set.
4398 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4399 ** SQL parameter is used more than once, second and subsequent
4400 ** occurrences have the same index as the first occurrence.
4401 ** ^The index for named parameters can be looked up using the
4402 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4403 ** for "?NNN" parameters is the value of NNN.
4404 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4405 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4407 ** ^The third argument is the value to bind to the parameter.
4408 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4409 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4410 ** is ignored and the end result is the same as sqlite3_bind_null().
4411 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4412 ** it should be a pointer to well-formed UTF8 text.
4413 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4414 ** it should be a pointer to well-formed UTF16 text.
4415 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4416 ** it should be a pointer to a well-formed unicode string that is
4417 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4420 ** [[byte-order determination rules]] ^The byte-order of
4421 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4422 ** found in first character, which is removed, or in the absence of a BOM
4423 ** the byte order is the native byte order of the host
4424 ** machine for sqlite3_bind_text16() or the byte order specified in
4425 ** the 6th parameter for sqlite3_bind_text64().)^
4426 ** ^If UTF16 input text contains invalid unicode
4427 ** characters, then SQLite might change those invalid characters
4428 ** into the unicode replacement character: U+FFFD.
4430 ** ^(In those routines that have a fourth argument, its value is the
4431 ** number of bytes in the parameter. To be clear: the value is the
4432 ** number of <u>bytes</u> in the value, not the number of characters.)^
4433 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4434 ** is negative, then the length of the string is
4435 ** the number of bytes up to the first zero terminator.
4436 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4437 ** the behavior is undefined.
4438 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4439 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4440 ** that parameter must be the byte offset
4441 ** where the NUL terminator would occur assuming the string were NUL
4442 ** terminated. If any NUL characters occurs at byte offsets less than
4443 ** the value of the fourth parameter then the resulting string value will
4444 ** contain embedded NULs. The result of expressions involving strings
4445 ** with embedded NULs is undefined.
4447 ** ^The fifth argument to the BLOB and string binding interfaces controls
4448 ** or indicates the lifetime of the object referenced by the third parameter.
4449 ** These three options exist:
4450 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4451 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4452 ** if the call to the bind API fails, except the destructor is not called if
4453 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4454 ** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that
4455 ** the application remains responsible for disposing of the object. ^In this
4456 ** case, the object and the provided pointer to it must remain valid until
4457 ** either the prepared statement is finalized or the same SQL parameter is
4458 ** bound to something else, whichever occurs sooner.
4459 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4460 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4461 ** object and pointer to it must remain valid until then. ^SQLite will then
4462 ** manage the lifetime of its private copy.
4464 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4465 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4466 ** to specify the encoding of the text in the third parameter. If
4467 ** the sixth argument to sqlite3_bind_text64() is not one of the
4468 ** allowed values shown above, or if the text encoding is different
4469 ** from the encoding specified by the sixth parameter, then the behavior
4472 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4473 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4474 ** (just an integer to hold its size) while it is being processed.
4475 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4476 ** content is later written using
4477 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4478 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4480 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4481 ** [prepared statement] S to have an SQL value of NULL, but to also be
4482 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4483 ** a pointer to a destructor function for P. ^SQLite will invoke the
4484 ** destructor D with a single argument of P when it is finished using
4485 ** P. The T parameter should be a static string, preferably a string
4486 ** literal. The sqlite3_bind_pointer() routine is part of the
4487 ** [pointer passing interface] added for SQLite 3.20.0.
4489 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4490 ** for the [prepared statement] or with a prepared statement for which
4491 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4492 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4493 ** routine is passed a [prepared statement] that has been finalized, the
4494 ** result is undefined and probably harmful.
4496 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4497 ** ^Unbound parameters are interpreted as NULL.
4499 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4500 ** [error code] if anything goes wrong.
4501 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4502 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4503 ** [SQLITE_MAX_LENGTH].
4504 ** ^[SQLITE_RANGE] is returned if the parameter
4505 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4507 ** See also: [sqlite3_bind_parameter_count()],
4508 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4510 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4511 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4513 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4514 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4515 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4516 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4517 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4518 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4519 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4520 void(*)(void*), unsigned char encoding);
4521 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4522 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4523 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4524 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4527 ** CAPI3REF: Number Of SQL Parameters
4528 ** METHOD: sqlite3_stmt
4530 ** ^This routine can be used to find the number of [SQL parameters]
4531 ** in a [prepared statement]. SQL parameters are tokens of the
4532 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4533 ** placeholders for values that are [sqlite3_bind_blob | bound]
4534 ** to the parameters at a later time.
4536 ** ^(This routine actually returns the index of the largest (rightmost)
4537 ** parameter. For all forms except ?NNN, this will correspond to the
4538 ** number of unique parameters. If parameters of the ?NNN form are used,
4539 ** there may be gaps in the list.)^
4541 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4542 ** [sqlite3_bind_parameter_name()], and
4543 ** [sqlite3_bind_parameter_index()].
4545 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4548 ** CAPI3REF: Name Of A Host Parameter
4549 ** METHOD: sqlite3_stmt
4551 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4552 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4553 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4554 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4556 ** In other words, the initial ":" or "$" or "@" or "?"
4557 ** is included as part of the name.)^
4558 ** ^Parameters of the form "?" without a following integer have no name
4559 ** and are referred to as "nameless" or "anonymous parameters".
4561 ** ^The first host parameter has an index of 1, not 0.
4563 ** ^If the value N is out of range or if the N-th parameter is
4564 ** nameless, then NULL is returned. ^The returned string is
4565 ** always in UTF-8 encoding even if the named parameter was
4566 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4567 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4569 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4570 ** [sqlite3_bind_parameter_count()], and
4571 ** [sqlite3_bind_parameter_index()].
4573 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4576 ** CAPI3REF: Index Of A Parameter With A Given Name
4577 ** METHOD: sqlite3_stmt
4579 ** ^Return the index of an SQL parameter given its name. ^The
4580 ** index value returned is suitable for use as the second
4581 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4582 ** is returned if no matching parameter is found. ^The parameter
4583 ** name must be given in UTF-8 even if the original statement
4584 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4585 ** [sqlite3_prepare16_v3()].
4587 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4588 ** [sqlite3_bind_parameter_count()], and
4589 ** [sqlite3_bind_parameter_name()].
4591 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4594 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4595 ** METHOD: sqlite3_stmt
4597 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4598 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4599 ** ^Use this routine to reset all host parameters to NULL.
4601 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4604 ** CAPI3REF: Number Of Columns In A Result Set
4605 ** METHOD: sqlite3_stmt
4607 ** ^Return the number of columns in the result set returned by the
4608 ** [prepared statement]. ^If this routine returns 0, that means the
4609 ** [prepared statement] returns no data (for example an [UPDATE]).
4610 ** ^However, just because this routine returns a positive number does not
4611 ** mean that one or more rows of data will be returned. ^A SELECT statement
4612 ** will always have a positive sqlite3_column_count() but depending on the
4613 ** WHERE clause constraints and the table content, it might return no rows.
4615 ** See also: [sqlite3_data_count()]
4617 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4620 ** CAPI3REF: Column Names In A Result Set
4621 ** METHOD: sqlite3_stmt
4623 ** ^These routines return the name assigned to a particular column
4624 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4625 ** interface returns a pointer to a zero-terminated UTF-8 string
4626 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4627 ** UTF-16 string. ^The first parameter is the [prepared statement]
4628 ** that implements the [SELECT] statement. ^The second parameter is the
4629 ** column number. ^The leftmost column is number 0.
4631 ** ^The returned string pointer is valid until either the [prepared statement]
4632 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4633 ** reprepared by the first call to [sqlite3_step()] for a particular run
4634 ** or until the next call to
4635 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4637 ** ^If sqlite3_malloc() fails during the processing of either routine
4638 ** (for example during a conversion from UTF-8 to UTF-16) then a
4639 ** NULL pointer is returned.
4641 ** ^The name of a result column is the value of the "AS" clause for
4642 ** that column, if there is an AS clause. If there is no AS clause
4643 ** then the name of the column is unspecified and may change from
4644 ** one release of SQLite to the next.
4646 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4647 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4650 ** CAPI3REF: Source Of Data In A Query Result
4651 ** METHOD: sqlite3_stmt
4653 ** ^These routines provide a means to determine the database, table, and
4654 ** table column that is the origin of a particular result column in
4655 ** [SELECT] statement.
4656 ** ^The name of the database or table or column can be returned as
4657 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4658 ** the database name, the _table_ routines return the table name, and
4659 ** the origin_ routines return the column name.
4660 ** ^The returned string is valid until the [prepared statement] is destroyed
4661 ** using [sqlite3_finalize()] or until the statement is automatically
4662 ** reprepared by the first call to [sqlite3_step()] for a particular run
4663 ** or until the same information is requested
4664 ** again in a different encoding.
4666 ** ^The names returned are the original un-aliased names of the
4667 ** database, table, and column.
4669 ** ^The first argument to these interfaces is a [prepared statement].
4670 ** ^These functions return information about the Nth result column returned by
4671 ** the statement, where N is the second function argument.
4672 ** ^The left-most column is column 0 for these routines.
4674 ** ^If the Nth column returned by the statement is an expression or
4675 ** subquery and is not a column value, then all of these functions return
4676 ** NULL. ^These routines might also return NULL if a memory allocation error
4677 ** occurs. ^Otherwise, they return the name of the attached database, table,
4678 ** or column that query result column was extracted from.
4680 ** ^As with all other SQLite APIs, those whose names end with "16" return
4681 ** UTF-16 encoded strings and the other functions return UTF-8.
4683 ** ^These APIs are only available if the library was compiled with the
4684 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4686 ** If two or more threads call one or more
4687 ** [sqlite3_column_database_name | column metadata interfaces]
4688 ** for the same [prepared statement] and result column
4689 ** at the same time then the results are undefined.
4691 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4692 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4693 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4694 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4695 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4696 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4699 ** CAPI3REF: Declared Datatype Of A Query Result
4700 ** METHOD: sqlite3_stmt
4702 ** ^(The first parameter is a [prepared statement].
4703 ** If this statement is a [SELECT] statement and the Nth column of the
4704 ** returned result set of that [SELECT] is a table column (not an
4705 ** expression or subquery) then the declared type of the table
4706 ** column is returned.)^ ^If the Nth column of the result set is an
4707 ** expression or subquery, then a NULL pointer is returned.
4708 ** ^The returned string is always UTF-8 encoded.
4710 ** ^(For example, given the database schema:
4712 ** CREATE TABLE t1(c1 VARIANT);
4714 ** and the following statement to be compiled:
4716 ** SELECT c1 + 1, c1 FROM t1;
4718 ** this routine would return the string "VARIANT" for the second result
4719 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4721 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4722 ** is declared to contain a particular type does not mean that the
4723 ** data stored in that column is of the declared type. SQLite is
4724 ** strongly typed, but the typing is dynamic not static. ^Type
4725 ** is associated with individual values, not with the containers
4726 ** used to hold those values.
4728 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4729 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4732 ** CAPI3REF: Evaluate An SQL Statement
4733 ** METHOD: sqlite3_stmt
4735 ** After a [prepared statement] has been prepared using any of
4736 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4737 ** or [sqlite3_prepare16_v3()] or one of the legacy
4738 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4739 ** must be called one or more times to evaluate the statement.
4741 ** The details of the behavior of the sqlite3_step() interface depend
4742 ** on whether the statement was prepared using the newer "vX" interfaces
4743 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4744 ** [sqlite3_prepare16_v2()] or the older legacy
4745 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4746 ** new "vX" interface is recommended for new applications but the legacy
4747 ** interface will continue to be supported.
4749 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4750 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4751 ** ^With the "v2" interface, any of the other [result codes] or
4752 ** [extended result codes] might be returned as well.
4754 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4755 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4756 ** or occurs outside of an explicit transaction, then you can retry the
4757 ** statement. If the statement is not a [COMMIT] and occurs within an
4758 ** explicit transaction then you should rollback the transaction before
4761 ** ^[SQLITE_DONE] means that the statement has finished executing
4762 ** successfully. sqlite3_step() should not be called again on this virtual
4763 ** machine without first calling [sqlite3_reset()] to reset the virtual
4764 ** machine back to its initial state.
4766 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4767 ** is returned each time a new row of data is ready for processing by the
4768 ** caller. The values may be accessed using the [column access functions].
4769 ** sqlite3_step() is called again to retrieve the next row of data.
4771 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4772 ** violation) has occurred. sqlite3_step() should not be called again on
4773 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4774 ** ^With the legacy interface, a more specific error code (for example,
4775 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4776 ** can be obtained by calling [sqlite3_reset()] on the
4777 ** [prepared statement]. ^In the "v2" interface,
4778 ** the more specific error code is returned directly by sqlite3_step().
4780 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4781 ** Perhaps it was called on a [prepared statement] that has
4782 ** already been [sqlite3_finalize | finalized] or on one that had
4783 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4784 ** be the case that the same database connection is being used by two or
4785 ** more threads at the same moment in time.
4787 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4788 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4789 ** other than [SQLITE_ROW] before any subsequent invocation of
4790 ** sqlite3_step(). Failure to reset the prepared statement using
4791 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4792 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4793 ** sqlite3_step() began
4794 ** calling [sqlite3_reset()] automatically in this circumstance rather
4795 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4796 ** break because any application that ever receives an SQLITE_MISUSE error
4797 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4798 ** can be used to restore the legacy behavior.
4800 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4801 ** API always returns a generic error code, [SQLITE_ERROR], following any
4802 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4803 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4804 ** specific [error codes] that better describes the error.
4805 ** We admit that this is a goofy design. The problem has been fixed
4806 ** with the "v2" interface. If you prepare all of your SQL statements
4807 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4808 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4809 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4810 ** then the more specific [error codes] are returned directly
4811 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4813 SQLITE_API int sqlite3_step(sqlite3_stmt*);
4816 ** CAPI3REF: Number of columns in a result set
4817 ** METHOD: sqlite3_stmt
4819 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4820 ** current row of the result set of [prepared statement] P.
4821 ** ^If prepared statement P does not have results ready to return
4822 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4823 ** interfaces) then sqlite3_data_count(P) returns 0.
4824 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4825 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4826 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4827 ** will return non-zero if previous call to [sqlite3_step](P) returned
4828 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4829 ** where it always returns zero since each step of that multi-step
4830 ** pragma returns 0 columns of data.
4832 ** See also: [sqlite3_column_count()]
4834 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4837 ** CAPI3REF: Fundamental Datatypes
4838 ** KEYWORDS: SQLITE_TEXT
4840 ** ^(Every value in SQLite has one of five fundamental datatypes:
4843 ** <li> 64-bit signed integer
4844 ** <li> 64-bit IEEE floating point number
4850 ** These constants are codes for each of those types.
4852 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4853 ** for a completely different meaning. Software that links against both
4854 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4857 #define SQLITE_INTEGER 1
4858 #define SQLITE_FLOAT 2
4859 #define SQLITE_BLOB 4
4860 #define SQLITE_NULL 5
4864 # define SQLITE_TEXT 3
4866 #define SQLITE3_TEXT 3
4869 ** CAPI3REF: Result Values From A Query
4870 ** KEYWORDS: {column access functions}
4871 ** METHOD: sqlite3_stmt
4874 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4875 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
4876 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
4877 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
4878 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
4879 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
4880 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
4881 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
4882 ** [sqlite3_value|unprotected sqlite3_value] object.
4883 ** <tr><td> <td> <td>
4884 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
4885 ** or a UTF-8 TEXT result in bytes
4886 ** <tr><td><b>sqlite3_column_bytes16 </b>
4887 ** <td>→ <td>Size of UTF-16
4889 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
4890 ** datatype of the result
4891 ** </table></blockquote>
4895 ** ^These routines return information about a single column of the current
4896 ** result row of a query. ^In every case the first argument is a pointer
4897 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4898 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4899 ** and the second argument is the index of the column for which information
4900 ** should be returned. ^The leftmost column of the result set has the index 0.
4901 ** ^The number of columns in the result can be determined using
4902 ** [sqlite3_column_count()].
4904 ** If the SQL statement does not currently point to a valid row, or if the
4905 ** column index is out of range, the result is undefined.
4906 ** These routines may only be called when the most recent call to
4907 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4908 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4909 ** If any of these routines are called after [sqlite3_reset()] or
4910 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4911 ** something other than [SQLITE_ROW], the results are undefined.
4912 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4913 ** are called from a different thread while any of these routines
4914 ** are pending, then the results are undefined.
4916 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4917 ** each return the value of a result column in a specific data format. If
4918 ** the result column is not initially in the requested format (for example,
4919 ** if the query returns an integer but the sqlite3_column_text() interface
4920 ** is used to extract the value) then an automatic type conversion is performed.
4922 ** ^The sqlite3_column_type() routine returns the
4923 ** [SQLITE_INTEGER | datatype code] for the initial data type
4924 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4925 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4926 ** The return value of sqlite3_column_type() can be used to decide which
4927 ** of the first six interface should be used to extract the column value.
4928 ** The value returned by sqlite3_column_type() is only meaningful if no
4929 ** automatic type conversions have occurred for the value in question.
4930 ** After a type conversion, the result of calling sqlite3_column_type()
4931 ** is undefined, though harmless. Future
4932 ** versions of SQLite may change the behavior of sqlite3_column_type()
4933 ** following a type conversion.
4935 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4936 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
4937 ** of that BLOB or string.
4939 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4940 ** routine returns the number of bytes in that BLOB or string.
4941 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4942 ** the string to UTF-8 and then returns the number of bytes.
4943 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
4944 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4945 ** the number of bytes in that string.
4946 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4948 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4949 ** routine returns the number of bytes in that BLOB or string.
4950 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4951 ** the string to UTF-16 and then returns the number of bytes.
4952 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4953 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4954 ** the number of bytes in that string.
4955 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4957 ** ^The values returned by [sqlite3_column_bytes()] and
4958 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4959 ** of the string. ^For clarity: the values returned by
4960 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4961 ** bytes in the string, not the number of characters.
4963 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4964 ** even empty strings, are always zero-terminated. ^The return
4965 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4967 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4968 ** [unprotected sqlite3_value] object. In a multithreaded environment,
4969 ** an unprotected sqlite3_value object may only be used safely with
4970 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
4971 ** If the [unprotected sqlite3_value] object returned by
4972 ** [sqlite3_column_value()] is used in any other way, including calls
4973 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4974 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4975 ** Hence, the sqlite3_column_value() interface
4976 ** is normally only useful within the implementation of
4977 ** [application-defined SQL functions] or [virtual tables], not within
4978 ** top-level application code.
4980 ** The these routines may attempt to convert the datatype of the result.
4981 ** ^For example, if the internal representation is FLOAT and a text result
4982 ** is requested, [sqlite3_snprintf()] is used internally to perform the
4983 ** conversion automatically. ^(The following table details the conversions
4984 ** that are applied:
4987 ** <table border="1">
4988 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4990 ** <tr><td> NULL <td> INTEGER <td> Result is 0
4991 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4992 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4993 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4994 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4995 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4996 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4997 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4998 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4999 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5000 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5001 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5002 ** <tr><td> TEXT <td> BLOB <td> No change
5003 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5004 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5005 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
5009 ** Note that when type conversions occur, pointers returned by prior
5010 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5011 ** sqlite3_column_text16() may be invalidated.
5012 ** Type conversions and pointer invalidations might occur
5013 ** in the following cases:
5016 ** <li> The initial content is a BLOB and sqlite3_column_text() or
5017 ** sqlite3_column_text16() is called. A zero-terminator might
5018 ** need to be added to the string.</li>
5019 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5020 ** sqlite3_column_text16() is called. The content must be converted
5022 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5023 ** sqlite3_column_text() is called. The content must be converted
5027 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5028 ** not invalidate a prior pointer, though of course the content of the buffer
5029 ** that the prior pointer references will have been modified. Other kinds
5030 ** of conversion are done in place when it is possible, but sometimes they
5031 ** are not possible and in those cases prior pointers are invalidated.
5033 ** The safest policy is to invoke these routines
5034 ** in one of the following ways:
5037 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5038 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5039 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5042 ** In other words, you should call sqlite3_column_text(),
5043 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5044 ** into the desired format, then invoke sqlite3_column_bytes() or
5045 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5046 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5047 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5048 ** with calls to sqlite3_column_bytes().
5050 ** ^The pointers returned are valid until a type conversion occurs as
5051 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5052 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5053 ** and BLOBs is freed automatically. Do not pass the pointers returned
5054 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5055 ** [sqlite3_free()].
5057 ** As long as the input parameters are correct, these routines will only
5058 ** fail if an out-of-memory error occurs during a format conversion.
5059 ** Only the following subset of interfaces are subject to out-of-memory
5063 ** <li> sqlite3_column_blob()
5064 ** <li> sqlite3_column_text()
5065 ** <li> sqlite3_column_text16()
5066 ** <li> sqlite3_column_bytes()
5067 ** <li> sqlite3_column_bytes16()
5070 ** If an out-of-memory error occurs, then the return value from these
5071 ** routines is the same as if the column had contained an SQL NULL value.
5072 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5073 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5074 ** return value is obtained and before any
5075 ** other SQLite interface is called on the same [database connection].
5077 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5078 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5079 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5080 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5081 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5082 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5083 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5084 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5085 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5086 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5089 ** CAPI3REF: Destroy A Prepared Statement Object
5090 ** DESTRUCTOR: sqlite3_stmt
5092 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5093 ** ^If the most recent evaluation of the statement encountered no errors
5094 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
5095 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5096 ** sqlite3_finalize(S) returns the appropriate [error code] or
5097 ** [extended error code].
5099 ** ^The sqlite3_finalize(S) routine can be called at any point during
5100 ** the life cycle of [prepared statement] S:
5101 ** before statement S is ever evaluated, after
5102 ** one or more calls to [sqlite3_reset()], or after any call
5103 ** to [sqlite3_step()] regardless of whether or not the statement has
5104 ** completed execution.
5106 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5108 ** The application must finalize every [prepared statement] in order to avoid
5109 ** resource leaks. It is a grievous error for the application to try to use
5110 ** a prepared statement after it has been finalized. Any use of a prepared
5111 ** statement after it has been finalized can result in undefined and
5112 ** undesirable behavior such as segfaults and heap corruption.
5114 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5117 ** CAPI3REF: Reset A Prepared Statement Object
5118 ** METHOD: sqlite3_stmt
5120 ** The sqlite3_reset() function is called to reset a [prepared statement]
5121 ** object back to its initial state, ready to be re-executed.
5122 ** ^Any SQL statement variables that had values bound to them using
5123 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5124 ** Use [sqlite3_clear_bindings()] to reset the bindings.
5126 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5127 ** back to the beginning of its program.
5129 ** ^If the most recent call to [sqlite3_step(S)] for the
5130 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5131 ** or if [sqlite3_step(S)] has never before been called on S,
5132 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
5134 ** ^If the most recent call to [sqlite3_step(S)] for the
5135 ** [prepared statement] S indicated an error, then
5136 ** [sqlite3_reset(S)] returns an appropriate [error code].
5138 ** ^The [sqlite3_reset(S)] interface does not change the values
5139 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5141 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5144 ** CAPI3REF: Create Or Redefine SQL Functions
5145 ** KEYWORDS: {function creation routines}
5148 ** ^These functions (collectively known as "function creation routines")
5149 ** are used to add SQL functions or aggregates or to redefine the behavior
5150 ** of existing SQL functions or aggregates. The only differences between
5151 ** the three "sqlite3_create_function*" routines are the text encoding
5152 ** expected for the second parameter (the name of the function being
5153 ** created) and the presence or absence of a destructor callback for
5154 ** the application data pointer. Function sqlite3_create_window_function()
5155 ** is similar, but allows the user to supply the extra callback functions
5156 ** needed by [aggregate window functions].
5158 ** ^The first parameter is the [database connection] to which the SQL
5159 ** function is to be added. ^If an application uses more than one database
5160 ** connection then application-defined SQL functions must be added
5161 ** to each database connection separately.
5163 ** ^The second parameter is the name of the SQL function to be created or
5164 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5165 ** representation, exclusive of the zero-terminator. ^Note that the name
5166 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5167 ** ^Any attempt to create a function with a longer name
5168 ** will result in [SQLITE_MISUSE] being returned.
5170 ** ^The third parameter (nArg)
5171 ** is the number of arguments that the SQL function or
5172 ** aggregate takes. ^If this parameter is -1, then the SQL function or
5173 ** aggregate may take any number of arguments between 0 and the limit
5174 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5175 ** parameter is less than -1 or greater than 127 then the behavior is
5178 ** ^The fourth parameter, eTextRep, specifies what
5179 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5180 ** its parameters. The application should set this parameter to
5181 ** [SQLITE_UTF16LE] if the function implementation invokes
5182 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5183 ** implementation invokes [sqlite3_value_text16be()] on an input, or
5184 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5185 ** otherwise. ^The same SQL function may be registered multiple times using
5186 ** different preferred text encodings, with different implementations for
5188 ** ^When multiple implementations of the same function are available, SQLite
5189 ** will pick the one that involves the least amount of data conversion.
5191 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5192 ** to signal that the function will always return the same result given
5193 ** the same inputs within a single SQL statement. Most SQL functions are
5194 ** deterministic. The built-in [random()] SQL function is an example of a
5195 ** function that is not deterministic. The SQLite query planner is able to
5196 ** perform additional optimizations on deterministic functions, so use
5197 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5199 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5200 ** flag, which if present prevents the function from being invoked from
5201 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5202 ** index expressions, or the WHERE clause of partial indexes.
5204 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5205 ** all application-defined SQL functions that do not need to be
5206 ** used inside of triggers, view, CHECK constraints, or other elements of
5207 ** the database schema. This flags is especially recommended for SQL
5208 ** functions that have side effects or reveal internal application state.
5209 ** Without this flag, an attacker might be able to modify the schema of
5210 ** a database file to include invocations of the function with parameters
5211 ** chosen by the attacker, which the application will then execute when
5212 ** the database file is opened and read.
5214 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5215 ** function can gain access to this pointer using [sqlite3_user_data()].)^
5217 ** ^The sixth, seventh and eighth parameters passed to the three
5218 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5219 ** pointers to C-language functions that implement the SQL function or
5220 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5221 ** callback only; NULL pointers must be passed as the xStep and xFinal
5222 ** parameters. ^An aggregate SQL function requires an implementation of xStep
5223 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5224 ** SQL function or aggregate, pass NULL pointers for all three function
5227 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5228 ** and xInverse) passed to sqlite3_create_window_function are pointers to
5229 ** C-language callbacks that implement the new function. xStep and xFinal
5230 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5231 ** which case a regular aggregate function is created, or must both be
5232 ** non-NULL, in which case the new function may be used as either an aggregate
5233 ** or aggregate window function. More details regarding the implementation
5234 ** of aggregate window functions are
5235 ** [user-defined window functions|available here].
5237 ** ^(If the final parameter to sqlite3_create_function_v2() or
5238 ** sqlite3_create_window_function() is not NULL, then it is destructor for
5239 ** the application data pointer. The destructor is invoked when the function
5240 ** is deleted, either by being overloaded or when the database connection
5241 ** closes.)^ ^The destructor is also invoked if the call to
5242 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5243 ** invoked, it is passed a single argument which is a copy of the application
5244 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5246 ** ^It is permitted to register multiple implementations of the same
5247 ** functions with the same name but with either differing numbers of
5248 ** arguments or differing preferred text encodings. ^SQLite will use
5249 ** the implementation that most closely matches the way in which the
5250 ** SQL function is used. ^A function implementation with a non-negative
5251 ** nArg parameter is a better match than a function implementation with
5252 ** a negative nArg. ^A function where the preferred text encoding
5253 ** matches the database encoding is a better
5254 ** match than a function where the encoding is different.
5255 ** ^A function where the encoding difference is between UTF16le and UTF16be
5256 ** is a closer match than a function where the encoding difference is
5257 ** between UTF8 and UTF16.
5259 ** ^Built-in functions may be overloaded by new application-defined functions.
5261 ** ^An application-defined function is permitted to call other
5262 ** SQLite interfaces. However, such calls must not
5263 ** close the database connection nor finalize or reset the prepared
5264 ** statement in which the function is running.
5266 SQLITE_API int sqlite3_create_function(
5268 const char *zFunctionName,
5272 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5273 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5274 void (*xFinal)(sqlite3_context*)
5276 SQLITE_API int sqlite3_create_function16(
5278 const void *zFunctionName,
5282 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5283 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5284 void (*xFinal)(sqlite3_context*)
5286 SQLITE_API int sqlite3_create_function_v2(
5288 const char *zFunctionName,
5292 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5293 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5294 void (*xFinal)(sqlite3_context*),
5295 void(*xDestroy)(void*)
5297 SQLITE_API int sqlite3_create_window_function(
5299 const char *zFunctionName,
5303 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5304 void (*xFinal)(sqlite3_context*),
5305 void (*xValue)(sqlite3_context*),
5306 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5307 void(*xDestroy)(void*)
5311 ** CAPI3REF: Text Encodings
5313 ** These constant define integer codes that represent the various
5314 ** text encodings supported by SQLite.
5316 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5317 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5318 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5319 #define SQLITE_UTF16 4 /* Use native byte order */
5320 #define SQLITE_ANY 5 /* Deprecated */
5321 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5324 ** CAPI3REF: Function Flags
5326 ** These constants may be ORed together with the
5327 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5328 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5329 ** [sqlite3_create_function_v2()].
5332 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5333 ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5334 ** the same output when the input parameters are the same.
5335 ** The [abs|abs() function] is deterministic, for example, but
5336 ** [randomblob|randomblob()] is not. Functions must
5337 ** be deterministic in order to be used in certain contexts such as
5338 ** with the WHERE clause of [partial indexes] or in [generated columns].
5339 ** SQLite might also optimize deterministic functions by factoring them
5340 ** out of inner loops.
5343 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5344 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5345 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5346 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5347 ** [expression indexes], [partial indexes], or [generated columns].
5348 ** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5349 ** for all [application-defined SQL functions], and especially for functions
5350 ** that have side-effects or that could potentially leak sensitive
5354 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5355 ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5356 ** to cause problems even if misused. An innocuous function should have
5357 ** no side effects and should not depend on any values other than its
5358 ** input parameters. The [abs|abs() function] is an example of an
5359 ** innocuous function.
5360 ** The [load_extension() SQL function] is not innocuous because of its
5362 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5363 ** exactly the same. The [random|random() function] is an example of a
5364 ** function that is innocuous but not deterministic.
5365 ** <p>Some heightened security settings
5366 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5367 ** disable the use of SQL functions inside views and triggers and in
5368 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5369 ** [expression indexes], [partial indexes], and [generated columns] unless
5370 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5371 ** are innocuous. Developers are advised to avoid using the
5372 ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5373 ** function has been carefully audited and found to be free of potentially
5374 ** security-adverse side-effects and information-leaks.
5377 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5378 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5379 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5380 ** Specifying this flag makes no difference for scalar or aggregate user
5381 ** functions. However, if it is not specified for a user-defined window
5382 ** function, then any sub-types belonging to arguments passed to the window
5383 ** function may be discarded before the window function is called (i.e.
5384 ** sqlite3_value_subtype() will always return 0).
5388 #define SQLITE_DETERMINISTIC 0x000000800
5389 #define SQLITE_DIRECTONLY 0x000080000
5390 #define SQLITE_SUBTYPE 0x000100000
5391 #define SQLITE_INNOCUOUS 0x000200000
5394 ** CAPI3REF: Deprecated Functions
5397 ** These functions are [deprecated]. In order to maintain
5398 ** backwards compatibility with older code, these functions continue
5399 ** to be supported. However, new applications should avoid
5400 ** the use of these functions. To encourage programmers to avoid
5401 ** these functions, we will not explain what they do.
5403 #ifndef SQLITE_OMIT_DEPRECATED
5404 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5405 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5406 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5407 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5408 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5409 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5410 void*,sqlite3_int64);
5414 ** CAPI3REF: Obtaining SQL Values
5415 ** METHOD: sqlite3_value
5418 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5419 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5420 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5421 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5422 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5423 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5424 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5425 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5426 ** the native byteorder
5427 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5428 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5429 ** <tr><td> <td> <td>
5430 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5431 ** or a UTF-8 TEXT in bytes
5432 ** <tr><td><b>sqlite3_value_bytes16 </b>
5433 ** <td>→ <td>Size of UTF-16
5435 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5436 ** datatype of the value
5437 ** <tr><td><b>sqlite3_value_numeric_type </b>
5438 ** <td>→ <td>Best numeric datatype of the value
5439 ** <tr><td><b>sqlite3_value_nochange </b>
5440 ** <td>→ <td>True if the column is unchanged in an UPDATE
5441 ** against a virtual table.
5442 ** <tr><td><b>sqlite3_value_frombind </b>
5443 ** <td>→ <td>True if value originated from a [bound parameter]
5444 ** </table></blockquote>
5448 ** These routines extract type, size, and content information from
5449 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5450 ** are used to pass parameter information into the functions that
5451 ** implement [application-defined SQL functions] and [virtual tables].
5453 ** These routines work only with [protected sqlite3_value] objects.
5454 ** Any attempt to use these routines on an [unprotected sqlite3_value]
5455 ** is not threadsafe.
5457 ** ^These routines work just like the corresponding [column access functions]
5458 ** except that these routines take a single [protected sqlite3_value] object
5459 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5461 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5462 ** in the native byte-order of the host machine. ^The
5463 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5464 ** extract UTF-16 strings as big-endian and little-endian respectively.
5466 ** ^If [sqlite3_value] object V was initialized
5467 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5468 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5469 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5470 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5471 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5473 ** ^(The sqlite3_value_type(V) interface returns the
5474 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5475 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5476 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5477 ** Other interfaces might change the datatype for an sqlite3_value object.
5478 ** For example, if the datatype is initially SQLITE_INTEGER and
5479 ** sqlite3_value_text(V) is called to extract a text value for that
5480 ** integer, then subsequent calls to sqlite3_value_type(V) might return
5481 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5482 ** occurs is undefined and may change from one release of SQLite to the next.
5484 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5485 ** numeric affinity to the value. This means that an attempt is
5486 ** made to convert the value to an integer or floating point. If
5487 ** such a conversion is possible without loss of information (in other
5488 ** words, if the value is a string that looks like a number)
5489 ** then the conversion is performed. Otherwise no conversion occurs.
5490 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5492 ** ^Within the [xUpdate] method of a [virtual table], the
5493 ** sqlite3_value_nochange(X) interface returns true if and only if
5494 ** the column corresponding to X is unchanged by the UPDATE operation
5495 ** that the xUpdate method call was invoked to implement and if
5496 ** and the prior [xColumn] method call that was invoked to extracted
5497 ** the value for that column returned without setting a result (probably
5498 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5499 ** was unchanging). ^Within an [xUpdate] method, any value for which
5500 ** sqlite3_value_nochange(X) is true will in all other respects appear
5501 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5502 ** than within an [xUpdate] method call for an UPDATE statement, then
5503 ** the return value is arbitrary and meaningless.
5505 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5506 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5507 ** interfaces. ^If X comes from an SQL literal value, or a table column,
5508 ** or an expression, then sqlite3_value_frombind(X) returns zero.
5510 ** Please pay particular attention to the fact that the pointer returned
5511 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5512 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5513 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5514 ** or [sqlite3_value_text16()].
5516 ** These routines must be called from the same thread as
5517 ** the SQL function that supplied the [sqlite3_value*] parameters.
5519 ** As long as the input parameter is correct, these routines can only
5520 ** fail if an out-of-memory error occurs during a format conversion.
5521 ** Only the following subset of interfaces are subject to out-of-memory
5525 ** <li> sqlite3_value_blob()
5526 ** <li> sqlite3_value_text()
5527 ** <li> sqlite3_value_text16()
5528 ** <li> sqlite3_value_text16le()
5529 ** <li> sqlite3_value_text16be()
5530 ** <li> sqlite3_value_bytes()
5531 ** <li> sqlite3_value_bytes16()
5534 ** If an out-of-memory error occurs, then the return value from these
5535 ** routines is the same as if the column had contained an SQL NULL value.
5536 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5537 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5538 ** return value is obtained and before any
5539 ** other SQLite interface is called on the same [database connection].
5541 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5542 SQLITE_API double sqlite3_value_double(sqlite3_value*);
5543 SQLITE_API int sqlite3_value_int(sqlite3_value*);
5544 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5545 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5546 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5547 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5548 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5549 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5550 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5551 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5552 SQLITE_API int sqlite3_value_type(sqlite3_value*);
5553 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5554 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5555 SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5558 ** CAPI3REF: Finding The Subtype Of SQL Values
5559 ** METHOD: sqlite3_value
5561 ** The sqlite3_value_subtype(V) function returns the subtype for
5562 ** an [application-defined SQL function] argument V. The subtype
5563 ** information can be used to pass a limited amount of context from
5564 ** one SQL function to another. Use the [sqlite3_result_subtype()]
5565 ** routine to set the subtype for the return value of an SQL function.
5567 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5570 ** CAPI3REF: Copy And Free SQL Values
5571 ** METHOD: sqlite3_value
5573 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5574 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5575 ** is a [protected sqlite3_value] object even if the input is not.
5576 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5577 ** memory allocation fails.
5579 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5580 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5581 ** then sqlite3_value_free(V) is a harmless no-op.
5583 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5584 SQLITE_API void sqlite3_value_free(sqlite3_value*);
5587 ** CAPI3REF: Obtain Aggregate Function Context
5588 ** METHOD: sqlite3_context
5590 ** Implementations of aggregate SQL functions use this
5591 ** routine to allocate memory for storing their state.
5593 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5594 ** for a particular aggregate function, SQLite allocates
5595 ** N bytes of memory, zeroes out that memory, and returns a pointer
5596 ** to the new memory. ^On second and subsequent calls to
5597 ** sqlite3_aggregate_context() for the same aggregate function instance,
5598 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5599 ** called once for each invocation of the xStep callback and then one
5600 ** last time when the xFinal callback is invoked. ^(When no rows match
5601 ** an aggregate query, the xStep() callback of the aggregate function
5602 ** implementation is never called and xFinal() is called exactly once.
5603 ** In those cases, sqlite3_aggregate_context() might be called for the
5604 ** first time from within xFinal().)^
5606 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5607 ** when first called if N is less than or equal to zero or if a memory
5608 ** allocate error occurs.
5610 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5611 ** determined by the N parameter on first successful call. Changing the
5612 ** value of N in any subsequent call to sqlite3_aggregate_context() within
5613 ** the same aggregate function instance will not resize the memory
5614 ** allocation.)^ Within the xFinal callback, it is customary to set
5615 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5616 ** pointless memory allocations occur.
5618 ** ^SQLite automatically frees the memory allocated by
5619 ** sqlite3_aggregate_context() when the aggregate query concludes.
5621 ** The first parameter must be a copy of the
5622 ** [sqlite3_context | SQL function context] that is the first parameter
5623 ** to the xStep or xFinal callback routine that implements the aggregate
5626 ** This routine must be called from the same thread in which
5627 ** the aggregate SQL function is running.
5629 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5632 ** CAPI3REF: User Data For Functions
5633 ** METHOD: sqlite3_context
5635 ** ^The sqlite3_user_data() interface returns a copy of
5636 ** the pointer that was the pUserData parameter (the 5th parameter)
5637 ** of the [sqlite3_create_function()]
5638 ** and [sqlite3_create_function16()] routines that originally
5639 ** registered the application defined function.
5641 ** This routine must be called from the same thread in which
5642 ** the application-defined function is running.
5644 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5647 ** CAPI3REF: Database Connection For Functions
5648 ** METHOD: sqlite3_context
5650 ** ^The sqlite3_context_db_handle() interface returns a copy of
5651 ** the pointer to the [database connection] (the 1st parameter)
5652 ** of the [sqlite3_create_function()]
5653 ** and [sqlite3_create_function16()] routines that originally
5654 ** registered the application defined function.
5656 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5659 ** CAPI3REF: Function Auxiliary Data
5660 ** METHOD: sqlite3_context
5662 ** These functions may be used by (non-aggregate) SQL functions to
5663 ** associate metadata with argument values. If the same value is passed to
5664 ** multiple invocations of the same SQL function during query execution, under
5665 ** some circumstances the associated metadata may be preserved. An example
5666 ** of where this might be useful is in a regular-expression matching
5667 ** function. The compiled version of the regular expression can be stored as
5668 ** metadata associated with the pattern string.
5669 ** Then as long as the pattern string remains the same,
5670 ** the compiled regular expression can be reused on multiple
5671 ** invocations of the same function.
5673 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5674 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5675 ** value to the application-defined function. ^N is zero for the left-most
5676 ** function argument. ^If there is no metadata
5677 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5678 ** returns a NULL pointer.
5680 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5681 ** argument of the application-defined function. ^Subsequent
5682 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5683 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5684 ** NULL if the metadata has been discarded.
5685 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5686 ** SQLite will invoke the destructor function X with parameter P exactly
5687 ** once, when the metadata is discarded.
5688 ** SQLite is free to discard the metadata at any time, including: <ul>
5689 ** <li> ^(when the corresponding function parameter changes)^, or
5690 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5691 ** SQL statement)^, or
5692 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5694 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5695 ** allocation error occurs.)^ </ul>
5697 ** Note the last bullet in particular. The destructor X in
5698 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5699 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5700 ** should be called near the end of the function implementation and the
5701 ** function implementation should not make any use of P after
5702 ** sqlite3_set_auxdata() has been called.
5704 ** ^(In practice, metadata is preserved between function calls for
5705 ** function parameters that are compile-time constants, including literal
5706 ** values and [parameters] and expressions composed from the same.)^
5708 ** The value of the N parameter to these interfaces should be non-negative.
5709 ** Future enhancements may make use of negative N values to define new
5710 ** kinds of function caching behavior.
5712 ** These routines must be called from the same thread in which
5713 ** the SQL function is running.
5715 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5716 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5720 ** CAPI3REF: Constants Defining Special Destructor Behavior
5722 ** These are special values for the destructor that is passed in as the
5723 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5724 ** argument is SQLITE_STATIC, it means that the content pointer is constant
5725 ** and will never change. It does not need to be destroyed. ^The
5726 ** SQLITE_TRANSIENT value means that the content will likely change in
5727 ** the near future and that SQLite should make its own private copy of
5728 ** the content before returning.
5730 ** The typedef is necessary to work around problems in certain
5733 typedef void (*sqlite3_destructor_type)(void*);
5734 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
5735 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5738 ** CAPI3REF: Setting The Result Of An SQL Function
5739 ** METHOD: sqlite3_context
5741 ** These routines are used by the xFunc or xFinal callbacks that
5742 ** implement SQL functions and aggregates. See
5743 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
5744 ** for additional information.
5746 ** These functions work very much like the [parameter binding] family of
5747 ** functions used to bind values to host parameters in prepared statements.
5748 ** Refer to the [SQL parameter] documentation for additional information.
5750 ** ^The sqlite3_result_blob() interface sets the result from
5751 ** an application-defined function to be the BLOB whose content is pointed
5752 ** to by the second parameter and which is N bytes long where N is the
5755 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5756 ** interfaces set the result of the application-defined function to be
5757 ** a BLOB containing all zero bytes and N bytes in size.
5759 ** ^The sqlite3_result_double() interface sets the result from
5760 ** an application-defined function to be a floating point value specified
5761 ** by its 2nd argument.
5763 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5764 ** cause the implemented SQL function to throw an exception.
5765 ** ^SQLite uses the string pointed to by the
5766 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5767 ** as the text of an error message. ^SQLite interprets the error
5768 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
5769 ** interprets the string from sqlite3_result_error16() as UTF-16 using
5770 ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5771 ** ^If the third parameter to sqlite3_result_error()
5772 ** or sqlite3_result_error16() is negative then SQLite takes as the error
5773 ** message all text up through the first zero character.
5774 ** ^If the third parameter to sqlite3_result_error() or
5775 ** sqlite3_result_error16() is non-negative then SQLite takes that many
5776 ** bytes (not characters) from the 2nd parameter as the error message.
5777 ** ^The sqlite3_result_error() and sqlite3_result_error16()
5778 ** routines make a private copy of the error message text before
5779 ** they return. Hence, the calling function can deallocate or
5780 ** modify the text after they return without harm.
5781 ** ^The sqlite3_result_error_code() function changes the error code
5782 ** returned by SQLite as a result of an error in a function. ^By default,
5783 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5784 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5786 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5787 ** error indicating that a string or BLOB is too long to represent.
5789 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5790 ** error indicating that a memory allocation failed.
5792 ** ^The sqlite3_result_int() interface sets the return value
5793 ** of the application-defined function to be the 32-bit signed integer
5794 ** value given in the 2nd argument.
5795 ** ^The sqlite3_result_int64() interface sets the return value
5796 ** of the application-defined function to be the 64-bit signed integer
5797 ** value given in the 2nd argument.
5799 ** ^The sqlite3_result_null() interface sets the return value
5800 ** of the application-defined function to be NULL.
5802 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
5803 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5804 ** set the return value of the application-defined function to be
5805 ** a text string which is represented as UTF-8, UTF-16 native byte order,
5806 ** UTF-16 little endian, or UTF-16 big endian, respectively.
5807 ** ^The sqlite3_result_text64() interface sets the return value of an
5808 ** application-defined function to be a text string in an encoding
5809 ** specified by the fifth (and last) parameter, which must be one
5810 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5811 ** ^SQLite takes the text result from the application from
5812 ** the 2nd parameter of the sqlite3_result_text* interfaces.
5813 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5814 ** is negative, then SQLite takes result text from the 2nd parameter
5815 ** through the first zero character.
5816 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5817 ** is non-negative, then as many bytes (not characters) of the text
5818 ** pointed to by the 2nd parameter are taken as the application-defined
5819 ** function result. If the 3rd parameter is non-negative, then it
5820 ** must be the byte offset into the string where the NUL terminator would
5821 ** appear if the string where NUL terminated. If any NUL characters occur
5822 ** in the string at a byte offset that is less than the value of the 3rd
5823 ** parameter, then the resulting string will contain embedded NULs and the
5824 ** result of expressions operating on strings with embedded NULs is undefined.
5825 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5826 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5827 ** function as the destructor on the text or BLOB result when it has
5828 ** finished using that result.
5829 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5830 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5831 ** assumes that the text or BLOB result is in constant space and does not
5832 ** copy the content of the parameter nor call a destructor on the content
5833 ** when it has finished using that result.
5834 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
5835 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5836 ** then SQLite makes a copy of the result into space obtained
5837 ** from [sqlite3_malloc()] before it returns.
5839 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5840 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5841 ** when the encoding is not UTF8, if the input UTF16 begins with a
5842 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5843 ** string and the rest of the string is interpreted according to the
5844 ** byte-order specified by the BOM. ^The byte-order specified by
5845 ** the BOM at the beginning of the text overrides the byte-order
5846 ** specified by the interface procedure. ^So, for example, if
5847 ** sqlite3_result_text16le() is invoked with text that begins
5848 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5849 ** first two bytes of input are skipped and the remaining input
5850 ** is interpreted as UTF16BE text.
5852 ** ^For UTF16 input text to the sqlite3_result_text16(),
5853 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5854 ** sqlite3_result_text64() routines, if the text contains invalid
5855 ** UTF16 characters, the invalid characters might be converted
5856 ** into the unicode replacement character, U+FFFD.
5858 ** ^The sqlite3_result_value() interface sets the result of
5859 ** the application-defined function to be a copy of the
5860 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5861 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5862 ** so that the [sqlite3_value] specified in the parameter may change or
5863 ** be deallocated after sqlite3_result_value() returns without harm.
5864 ** ^A [protected sqlite3_value] object may always be used where an
5865 ** [unprotected sqlite3_value] object is required, so either
5866 ** kind of [sqlite3_value] object can be used with this interface.
5868 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5869 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5870 ** also associates the host-language pointer P or type T with that
5871 ** NULL value such that the pointer can be retrieved within an
5872 ** [application-defined SQL function] using [sqlite3_value_pointer()].
5873 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
5874 ** for the P parameter. ^SQLite invokes D with P as its only argument
5875 ** when SQLite is finished with P. The T parameter should be a static
5876 ** string and preferably a string literal. The sqlite3_result_pointer()
5877 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5879 ** If these routines are called from within the different thread
5880 ** than the one containing the application-defined function that received
5881 ** the [sqlite3_context] pointer, the results are undefined.
5883 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5884 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5885 sqlite3_uint64,void(*)(void*));
5886 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5887 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5888 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5889 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5890 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5891 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5892 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5893 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5894 SQLITE_API void sqlite3_result_null(sqlite3_context*);
5895 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5896 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5897 void(*)(void*), unsigned char encoding);
5898 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5899 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5900 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5901 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5902 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5903 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5904 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5908 ** CAPI3REF: Setting The Subtype Of An SQL Function
5909 ** METHOD: sqlite3_context
5911 ** The sqlite3_result_subtype(C,T) function causes the subtype of
5912 ** the result from the [application-defined SQL function] with
5913 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
5914 ** of the subtype T are preserved in current versions of SQLite;
5915 ** higher order bits are discarded.
5916 ** The number of subtype bytes preserved by SQLite might increase
5917 ** in future releases of SQLite.
5919 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5922 ** CAPI3REF: Define New Collating Sequences
5925 ** ^These functions add, remove, or modify a [collation] associated
5926 ** with the [database connection] specified as the first argument.
5928 ** ^The name of the collation is a UTF-8 string
5929 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5930 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5931 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5932 ** considered to be the same name.
5934 ** ^(The third argument (eTextRep) must be one of the constants:
5936 ** <li> [SQLITE_UTF8],
5937 ** <li> [SQLITE_UTF16LE],
5938 ** <li> [SQLITE_UTF16BE],
5939 ** <li> [SQLITE_UTF16], or
5940 ** <li> [SQLITE_UTF16_ALIGNED].
5942 ** ^The eTextRep argument determines the encoding of strings passed
5943 ** to the collating function callback, xCompare.
5944 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5945 ** force strings to be UTF16 with native byte order.
5946 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5947 ** on an even byte address.
5949 ** ^The fourth argument, pArg, is an application data pointer that is passed
5950 ** through as the first argument to the collating function callback.
5952 ** ^The fifth argument, xCompare, is a pointer to the collating function.
5953 ** ^Multiple collating functions can be registered using the same name but
5954 ** with different eTextRep parameters and SQLite will use whichever
5955 ** function requires the least amount of data transformation.
5956 ** ^If the xCompare argument is NULL then the collating function is
5957 ** deleted. ^When all collating functions having the same name are deleted,
5958 ** that collation is no longer usable.
5960 ** ^The collating function callback is invoked with a copy of the pArg
5961 ** application data pointer and with two strings in the encoding specified
5962 ** by the eTextRep argument. The two integer parameters to the collating
5963 ** function callback are the length of the two strings, in bytes. The collating
5964 ** function must return an integer that is negative, zero, or positive
5965 ** if the first string is less than, equal to, or greater than the second,
5966 ** respectively. A collating function must always return the same answer
5967 ** given the same inputs. If two or more collating functions are registered
5968 ** to the same collation name (using different eTextRep values) then all
5969 ** must give an equivalent answer when invoked with equivalent strings.
5970 ** The collating function must obey the following properties for all
5971 ** strings A, B, and C:
5974 ** <li> If A==B then B==A.
5975 ** <li> If A==B and B==C then A==C.
5976 ** <li> If A<B THEN B>A.
5977 ** <li> If A<B and B<C then A<C.
5980 ** If a collating function fails any of the above constraints and that
5981 ** collating function is registered and used, then the behavior of SQLite
5984 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5985 ** with the addition that the xDestroy callback is invoked on pArg when
5986 ** the collating function is deleted.
5987 ** ^Collating functions are deleted when they are overridden by later
5988 ** calls to the collation creation functions or when the
5989 ** [database connection] is closed using [sqlite3_close()].
5991 ** ^The xDestroy callback is <u>not</u> called if the
5992 ** sqlite3_create_collation_v2() function fails. Applications that invoke
5993 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5994 ** check the return code and dispose of the application data pointer
5995 ** themselves rather than expecting SQLite to deal with it for them.
5996 ** This is different from every other SQLite interface. The inconsistency
5997 ** is unfortunate but cannot be changed without breaking backwards
6000 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6002 SQLITE_API int sqlite3_create_collation(
6007 int(*xCompare)(void*,int,const void*,int,const void*)
6009 SQLITE_API int sqlite3_create_collation_v2(
6014 int(*xCompare)(void*,int,const void*,int,const void*),
6015 void(*xDestroy)(void*)
6017 SQLITE_API int sqlite3_create_collation16(
6022 int(*xCompare)(void*,int,const void*,int,const void*)
6026 ** CAPI3REF: Collation Needed Callbacks
6029 ** ^To avoid having to register all collation sequences before a database
6030 ** can be used, a single callback function may be registered with the
6031 ** [database connection] to be invoked whenever an undefined collation
6032 ** sequence is required.
6034 ** ^If the function is registered using the sqlite3_collation_needed() API,
6035 ** then it is passed the names of undefined collation sequences as strings
6036 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6037 ** the names are passed as UTF-16 in machine native byte order.
6038 ** ^A call to either function replaces the existing collation-needed callback.
6040 ** ^(When the callback is invoked, the first argument passed is a copy
6041 ** of the second argument to sqlite3_collation_needed() or
6042 ** sqlite3_collation_needed16(). The second argument is the database
6043 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6044 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6045 ** sequence function required. The fourth parameter is the name of the
6046 ** required collation sequence.)^
6048 ** The callback function should register the desired collation using
6049 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6050 ** [sqlite3_create_collation_v2()].
6052 SQLITE_API int sqlite3_collation_needed(
6055 void(*)(void*,sqlite3*,int eTextRep,const char*)
6057 SQLITE_API int sqlite3_collation_needed16(
6060 void(*)(void*,sqlite3*,int eTextRep,const void*)
6063 #ifdef SQLITE_ENABLE_CEROD
6065 ** Specify the activation key for a CEROD database. Unless
6066 ** activated, none of the CEROD routines will work.
6068 SQLITE_API void sqlite3_activate_cerod(
6069 const char *zPassPhrase /* Activation phrase */
6074 ** CAPI3REF: Suspend Execution For A Short Time
6076 ** The sqlite3_sleep() function causes the current thread to suspend execution
6077 ** for at least a number of milliseconds specified in its parameter.
6079 ** If the operating system does not support sleep requests with
6080 ** millisecond time resolution, then the time will be rounded up to
6081 ** the nearest second. The number of milliseconds of sleep actually
6082 ** requested from the operating system is returned.
6084 ** ^SQLite implements this interface by calling the xSleep()
6085 ** method of the default [sqlite3_vfs] object. If the xSleep() method
6086 ** of the default VFS is not implemented correctly, or not implemented at
6087 ** all, then the behavior of sqlite3_sleep() may deviate from the description
6088 ** in the previous paragraphs.
6090 SQLITE_API int sqlite3_sleep(int);
6093 ** CAPI3REF: Name Of The Folder Holding Temporary Files
6095 ** ^(If this global variable is made to point to a string which is
6096 ** the name of a folder (a.k.a. directory), then all temporary files
6097 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6098 ** will be placed in that directory.)^ ^If this variable
6099 ** is a NULL pointer, then SQLite performs a search for an appropriate
6100 ** temporary file directory.
6102 ** Applications are strongly discouraged from using this global variable.
6103 ** It is required to set a temporary folder on Windows Runtime (WinRT).
6104 ** But for all other platforms, it is highly recommended that applications
6105 ** neither read nor write this variable. This global variable is a relic
6106 ** that exists for backwards compatibility of legacy applications and should
6107 ** be avoided in new projects.
6109 ** It is not safe to read or modify this variable in more than one
6110 ** thread at a time. It is not safe to read or modify this variable
6111 ** if a [database connection] is being used at the same time in a separate
6113 ** It is intended that this variable be set once
6114 ** as part of process initialization and before any SQLite interface
6115 ** routines have been called and that this variable remain unchanged
6118 ** ^The [temp_store_directory pragma] may modify this variable and cause
6119 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6120 ** the [temp_store_directory pragma] always assumes that any string
6121 ** that this variable points to is held in memory obtained from
6122 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6123 ** using [sqlite3_free].
6124 ** Hence, if this variable is modified directly, either it should be
6125 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6126 ** or else the use of the [temp_store_directory pragma] should be avoided.
6127 ** Except when requested by the [temp_store_directory pragma], SQLite
6128 ** does not free the memory that sqlite3_temp_directory points to. If
6129 ** the application wants that memory to be freed, it must do
6130 ** so itself, taking care to only do so after all [database connection]
6131 ** objects have been destroyed.
6133 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6134 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6135 ** features that require the use of temporary files may fail. Here is an
6136 ** example of how to do this using C++ with the Windows Runtime:
6138 ** <blockquote><pre>
6139 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6140 ** TemporaryFolder->Path->Data();
6141 ** char zPathBuf[MAX_PATH + 1];
6142 ** memset(zPathBuf, 0, sizeof(zPathBuf));
6143 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6144 ** NULL, NULL);
6145 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6146 ** </pre></blockquote>
6148 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6151 ** CAPI3REF: Name Of The Folder Holding Database Files
6153 ** ^(If this global variable is made to point to a string which is
6154 ** the name of a folder (a.k.a. directory), then all database files
6155 ** specified with a relative pathname and created or accessed by
6156 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6157 ** to be relative to that directory.)^ ^If this variable is a NULL
6158 ** pointer, then SQLite assumes that all database files specified
6159 ** with a relative pathname are relative to the current directory
6160 ** for the process. Only the windows VFS makes use of this global
6161 ** variable; it is ignored by the unix VFS.
6163 ** Changing the value of this variable while a database connection is
6164 ** open can result in a corrupt database.
6166 ** It is not safe to read or modify this variable in more than one
6167 ** thread at a time. It is not safe to read or modify this variable
6168 ** if a [database connection] is being used at the same time in a separate
6170 ** It is intended that this variable be set once
6171 ** as part of process initialization and before any SQLite interface
6172 ** routines have been called and that this variable remain unchanged
6175 ** ^The [data_store_directory pragma] may modify this variable and cause
6176 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6177 ** the [data_store_directory pragma] always assumes that any string
6178 ** that this variable points to is held in memory obtained from
6179 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6180 ** using [sqlite3_free].
6181 ** Hence, if this variable is modified directly, either it should be
6182 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6183 ** or else the use of the [data_store_directory pragma] should be avoided.
6185 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6188 ** CAPI3REF: Win32 Specific Interface
6190 ** These interfaces are available only on Windows. The
6191 ** [sqlite3_win32_set_directory] interface is used to set the value associated
6192 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6193 ** zValue, depending on the value of the type parameter. The zValue parameter
6194 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6195 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6196 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6197 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6198 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6199 ** [sqlite3_data_directory] variable is intended to act as a replacement for
6200 ** the current directory on the sub-platforms of Win32 where that concept is
6201 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6202 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6203 ** sqlite3_win32_set_directory interface except the string parameter must be
6204 ** UTF-8 or UTF-16, respectively.
6206 SQLITE_API int sqlite3_win32_set_directory(
6207 unsigned long type, /* Identifier for directory being set or reset */
6208 void *zValue /* New value for directory being set or reset */
6210 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6211 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6214 ** CAPI3REF: Win32 Directory Types
6216 ** These macros are only available on Windows. They define the allowed values
6217 ** for the type argument to the [sqlite3_win32_set_directory] interface.
6219 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6220 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6223 ** CAPI3REF: Test For Auto-Commit Mode
6224 ** KEYWORDS: {autocommit mode}
6227 ** ^The sqlite3_get_autocommit() interface returns non-zero or
6228 ** zero if the given database connection is or is not in autocommit mode,
6229 ** respectively. ^Autocommit mode is on by default.
6230 ** ^Autocommit mode is disabled by a [BEGIN] statement.
6231 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6233 ** If certain kinds of errors occur on a statement within a multi-statement
6234 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6235 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6236 ** transaction might be rolled back automatically. The only way to
6237 ** find out whether SQLite automatically rolled back the transaction after
6238 ** an error is to use this function.
6240 ** If another thread changes the autocommit status of the database
6241 ** connection while this routine is running, then the return value
6244 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6247 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6248 ** METHOD: sqlite3_stmt
6250 ** ^The sqlite3_db_handle interface returns the [database connection] handle
6251 ** to which a [prepared statement] belongs. ^The [database connection]
6252 ** returned by sqlite3_db_handle is the same [database connection]
6253 ** that was the first argument
6254 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6255 ** create the statement in the first place.
6257 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6260 ** CAPI3REF: Return The Filename For A Database Connection
6263 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6264 ** associated with database N of connection D.
6265 ** ^If there is no attached database N on the database
6266 ** connection D, or if database N is a temporary or in-memory database, then
6267 ** this function will return either a NULL pointer or an empty string.
6269 ** ^The string value returned by this routine is owned and managed by
6270 ** the database connection. ^The value will be valid until the database N
6271 ** is [DETACH]-ed or until the database connection closes.
6273 ** ^The filename returned by this function is the output of the
6274 ** xFullPathname method of the [VFS]. ^In other words, the filename
6275 ** will be an absolute pathname, even if the filename used
6276 ** to open the database originally was a URI or relative pathname.
6278 ** If the filename pointer returned by this routine is not NULL, then it
6279 ** can be used as the filename input parameter to these routines:
6281 ** <li> [sqlite3_uri_parameter()]
6282 ** <li> [sqlite3_uri_boolean()]
6283 ** <li> [sqlite3_uri_int64()]
6284 ** <li> [sqlite3_filename_database()]
6285 ** <li> [sqlite3_filename_journal()]
6286 ** <li> [sqlite3_filename_wal()]
6289 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6292 ** CAPI3REF: Determine if a database is read-only
6295 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6296 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6297 ** the name of a database on connection D.
6299 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6302 ** CAPI3REF: Determine the transaction state of a database
6305 ** ^The sqlite3_txn_state(D,S) interface returns the current
6306 ** [transaction state] of schema S in database connection D. ^If S is NULL,
6307 ** then the highest transaction state of any schema on database connection D
6308 ** is returned. Transaction states are (in order of lowest to highest):
6310 ** <li value="0"> SQLITE_TXN_NONE
6311 ** <li value="1"> SQLITE_TXN_READ
6312 ** <li value="2"> SQLITE_TXN_WRITE
6314 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6315 ** a valid schema, then -1 is returned.
6317 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6320 ** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6321 ** KEYWORDS: {transaction state}
6323 ** These constants define the current transaction state of a database file.
6324 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6325 ** constants in order to describe the transaction state of schema S
6326 ** in [database connection] D.
6329 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6330 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6333 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6334 ** <dd>The SQLITE_TXN_READ state means that the database is currently
6335 ** in a read transaction. Content has been read from the database file
6336 ** but nothing in the database file has changed. The transaction state
6337 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6338 ** no other conflicting concurrent write transactions. The transaction
6339 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6342 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6343 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6344 ** in a write transaction. Content has been written to the database file
6345 ** but has not yet committed. The transaction state will change to
6346 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6348 #define SQLITE_TXN_NONE 0
6349 #define SQLITE_TXN_READ 1
6350 #define SQLITE_TXN_WRITE 2
6353 ** CAPI3REF: Find the next prepared statement
6356 ** ^This interface returns a pointer to the next [prepared statement] after
6357 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6358 ** then this interface returns a pointer to the first prepared statement
6359 ** associated with the database connection pDb. ^If no prepared statement
6360 ** satisfies the conditions of this routine, it returns NULL.
6362 ** The [database connection] pointer D in a call to
6363 ** [sqlite3_next_stmt(D,S)] must refer to an open database
6364 ** connection and in particular must not be a NULL pointer.
6366 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6369 ** CAPI3REF: Commit And Rollback Notification Callbacks
6372 ** ^The sqlite3_commit_hook() interface registers a callback
6373 ** function to be invoked whenever a transaction is [COMMIT | committed].
6374 ** ^Any callback set by a previous call to sqlite3_commit_hook()
6375 ** for the same database connection is overridden.
6376 ** ^The sqlite3_rollback_hook() interface registers a callback
6377 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6378 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6379 ** for the same database connection is overridden.
6380 ** ^The pArg argument is passed through to the callback.
6381 ** ^If the callback on a commit hook function returns non-zero,
6382 ** then the commit is converted into a rollback.
6384 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6385 ** return the P argument from the previous call of the same function
6386 ** on the same [database connection] D, or NULL for
6387 ** the first call for each function on D.
6389 ** The commit and rollback hook callbacks are not reentrant.
6390 ** The callback implementation must not do anything that will modify
6391 ** the database connection that invoked the callback. Any actions
6392 ** to modify the database connection must be deferred until after the
6393 ** completion of the [sqlite3_step()] call that triggered the commit
6394 ** or rollback hook in the first place.
6395 ** Note that running any other SQL statements, including SELECT statements,
6396 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6397 ** the database connections for the meaning of "modify" in this paragraph.
6399 ** ^Registering a NULL function disables the callback.
6401 ** ^When the commit hook callback routine returns zero, the [COMMIT]
6402 ** operation is allowed to continue normally. ^If the commit hook
6403 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6404 ** ^The rollback hook is invoked on a rollback that results from a commit
6405 ** hook returning non-zero, just as it would be with any other rollback.
6407 ** ^For the purposes of this API, a transaction is said to have been
6408 ** rolled back if an explicit "ROLLBACK" statement is executed, or
6409 ** an error or constraint causes an implicit rollback to occur.
6410 ** ^The rollback callback is not invoked if a transaction is
6411 ** automatically rolled back because the database connection is closed.
6413 ** See also the [sqlite3_update_hook()] interface.
6415 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6416 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6419 ** CAPI3REF: Autovacuum Compaction Amount Callback
6422 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6423 ** function C that is invoked prior to each autovacuum of the database
6424 ** file. ^The callback is passed a copy of the generic data pointer (P),
6425 ** the schema-name of the attached database that is being autovacuumed,
6426 ** the the size of the database file in pages, the number of free pages,
6427 ** and the number of bytes per page, respectively. The callback should
6428 ** return the number of free pages that should be removed by the
6429 ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6430 ** ^If the value returned is greater than or equal to the number of
6431 ** free pages, then a complete autovacuum happens.
6433 ** <p>^If there are multiple ATTACH-ed database files that are being
6434 ** modified as part of a transaction commit, then the autovacuum pages
6435 ** callback is invoked separately for each file.
6437 ** <p><b>The callback is not reentrant.</b> The callback function should
6438 ** not attempt to invoke any other SQLite interface. If it does, bad
6439 ** things may happen, including segmentation faults and corrupt database
6440 ** files. The callback function should be a simple function that
6441 ** does some arithmetic on its input parameters and returns a result.
6443 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6444 ** destructor for the P parameter. ^If X is not NULL, then X(P) is
6445 ** invoked whenever the database connection closes or when the callback
6446 ** is overwritten by another invocation of sqlite3_autovacuum_pages().
6448 ** <p>^There is only one autovacuum pages callback per database connection.
6449 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6450 ** previous invocations for that database connection. ^If the callback
6451 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6452 ** then the autovacuum steps callback is cancelled. The return value
6453 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6454 ** be some other error code if something goes wrong. The current
6455 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6456 ** return codes might be added in future releases.
6458 ** <p>If no autovacuum pages callback is specified (the usual case) or
6459 ** a NULL pointer is provided for the callback,
6460 ** then the default behavior is to vacuum all free pages. So, in other
6461 ** words, the default behavior is the same as if the callback function
6462 ** were something like this:
6464 ** <blockquote><pre>
6465 ** unsigned int demonstration_autovac_pages_callback(
6466 ** void *pClientData,
6467 ** const char *zSchema,
6468 ** unsigned int nDbPage,
6469 ** unsigned int nFreePage,
6470 ** unsigned int nBytePerPage
6472 ** return nFreePage;
6474 ** </pre></blockquote>
6476 SQLITE_API int sqlite3_autovacuum_pages(
6478 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6485 ** CAPI3REF: Data Change Notification Callbacks
6488 ** ^The sqlite3_update_hook() interface registers a callback function
6489 ** with the [database connection] identified by the first argument
6490 ** to be invoked whenever a row is updated, inserted or deleted in
6492 ** ^Any callback set by a previous call to this function
6493 ** for the same database connection is overridden.
6495 ** ^The second argument is a pointer to the function to invoke when a
6496 ** row is updated, inserted or deleted in a rowid table.
6497 ** ^The first argument to the callback is a copy of the third argument
6498 ** to sqlite3_update_hook().
6499 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6500 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
6502 ** ^The third and fourth arguments to the callback contain pointers to the
6503 ** database and table name containing the affected row.
6504 ** ^The final callback parameter is the [rowid] of the row.
6505 ** ^In the case of an update, this is the [rowid] after the update takes place.
6507 ** ^(The update hook is not invoked when internal system tables are
6508 ** modified (i.e. sqlite_sequence).)^
6509 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6511 ** ^In the current implementation, the update hook
6512 ** is not invoked when conflicting rows are deleted because of an
6513 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6514 ** invoked when rows are deleted using the [truncate optimization].
6515 ** The exceptions defined in this paragraph might change in a future
6516 ** release of SQLite.
6518 ** The update hook implementation must not do anything that will modify
6519 ** the database connection that invoked the update hook. Any actions
6520 ** to modify the database connection must be deferred until after the
6521 ** completion of the [sqlite3_step()] call that triggered the update hook.
6522 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6523 ** database connections for the meaning of "modify" in this paragraph.
6525 ** ^The sqlite3_update_hook(D,C,P) function
6526 ** returns the P argument from the previous call
6527 ** on the same [database connection] D, or NULL for
6528 ** the first call on D.
6530 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6531 ** and [sqlite3_preupdate_hook()] interfaces.
6533 SQLITE_API void *sqlite3_update_hook(
6535 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6540 ** CAPI3REF: Enable Or Disable Shared Pager Cache
6542 ** ^(This routine enables or disables the sharing of the database cache
6543 ** and schema data structures between [database connection | connections]
6544 ** to the same database. Sharing is enabled if the argument is true
6545 ** and disabled if the argument is false.)^
6547 ** ^Cache sharing is enabled and disabled for an entire process.
6548 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6549 ** In prior versions of SQLite,
6550 ** sharing was enabled or disabled for each thread separately.
6552 ** ^(The cache sharing mode set by this interface effects all subsequent
6553 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6554 ** Existing database connections continue to use the sharing mode
6555 ** that was in effect at the time they were opened.)^
6557 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6558 ** successfully. An [error code] is returned otherwise.)^
6560 ** ^Shared cache is disabled by default. It is recommended that it stay
6561 ** that way. In other words, do not use this routine. This interface
6562 ** continues to be provided for historical compatibility, but its use is
6563 ** discouraged. Any use of shared cache is discouraged. If shared cache
6564 ** must be used, it is recommended that shared cache only be enabled for
6565 ** individual database connections using the [sqlite3_open_v2()] interface
6566 ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6568 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6569 ** and will always return SQLITE_MISUSE. On those systems,
6570 ** shared cache mode should be enabled per-database connection via
6571 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6573 ** This interface is threadsafe on processors where writing a
6574 ** 32-bit integer is atomic.
6576 ** See Also: [SQLite Shared-Cache Mode]
6578 SQLITE_API int sqlite3_enable_shared_cache(int);
6581 ** CAPI3REF: Attempt To Free Heap Memory
6583 ** ^The sqlite3_release_memory() interface attempts to free N bytes
6584 ** of heap memory by deallocating non-essential memory allocations
6585 ** held by the database library. Memory used to cache database
6586 ** pages to improve performance is an example of non-essential memory.
6587 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
6588 ** which might be more or less than the amount requested.
6589 ** ^The sqlite3_release_memory() routine is a no-op returning zero
6590 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6592 ** See also: [sqlite3_db_release_memory()]
6594 SQLITE_API int sqlite3_release_memory(int);
6597 ** CAPI3REF: Free Memory Used By A Database Connection
6600 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6601 ** memory as possible from database connection D. Unlike the
6602 ** [sqlite3_release_memory()] interface, this interface is in effect even
6603 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6606 ** See also: [sqlite3_release_memory()]
6608 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6611 ** CAPI3REF: Impose A Limit On Heap Size
6613 ** These interfaces impose limits on the amount of heap memory that will be
6614 ** by all database connections within a single process.
6616 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6617 ** soft limit on the amount of heap memory that may be allocated by SQLite.
6618 ** ^SQLite strives to keep heap memory utilization below the soft heap
6619 ** limit by reducing the number of pages held in the page cache
6620 ** as heap memory usages approaches the limit.
6621 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
6622 ** below the limit, it will exceed the limit rather than generate
6623 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6624 ** is advisory only.
6626 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6627 ** N bytes on the amount of memory that will be allocated. ^The
6628 ** sqlite3_hard_heap_limit64(N) interface is similar to
6629 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6630 ** when the hard heap limit is reached.
6632 ** ^The return value from both sqlite3_soft_heap_limit64() and
6633 ** sqlite3_hard_heap_limit64() is the size of
6634 ** the heap limit prior to the call, or negative in the case of an
6635 ** error. ^If the argument N is negative
6636 ** then no change is made to the heap limit. Hence, the current
6637 ** size of heap limits can be determined by invoking
6638 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6640 ** ^Setting the heap limits to zero disables the heap limiter mechanism.
6642 ** ^The soft heap limit may not be greater than the hard heap limit.
6643 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6644 ** is invoked with a value of N that is greater than the hard heap limit,
6645 ** the the soft heap limit is set to the value of the hard heap limit.
6646 ** ^The soft heap limit is automatically enabled whenever the hard heap
6647 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6648 ** the soft heap limit is outside the range of 1..N, then the soft heap
6649 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6650 ** hard heap limit is enabled makes the soft heap limit equal to the
6653 ** The memory allocation limits can also be adjusted using
6654 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6656 ** ^(The heap limits are not enforced in the current implementation
6657 ** if one or more of following conditions are true:
6660 ** <li> The limit value is set to zero.
6661 ** <li> Memory accounting is disabled using a combination of the
6662 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6663 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6664 ** <li> An alternative page cache implementation is specified using
6665 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6666 ** <li> The page cache allocates from its own memory pool supplied
6667 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6671 ** The circumstances under which SQLite will enforce the heap limits may
6672 ** changes in future releases of SQLite.
6674 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6675 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6678 ** CAPI3REF: Deprecated Soft Heap Limit Interface
6681 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6682 ** interface. This routine is provided for historical compatibility
6683 ** only. All new applications should use the
6684 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
6686 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6690 ** CAPI3REF: Extract Metadata About A Column Of A Table
6693 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6694 ** information about column C of table T in database D
6695 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6696 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
6697 ** the final five arguments with appropriate values if the specified
6698 ** column exists. ^The sqlite3_table_column_metadata() interface returns
6699 ** SQLITE_ERROR if the specified column does not exist.
6700 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6701 ** NULL pointer, then this routine simply checks for the existence of the
6702 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6703 ** does not. If the table name parameter T in a call to
6704 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6705 ** undefined behavior.
6707 ** ^The column is identified by the second, third and fourth parameters to
6708 ** this function. ^(The second parameter is either the name of the database
6709 ** (i.e. "main", "temp", or an attached database) containing the specified
6710 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6711 ** for the table using the same algorithm used by the database engine to
6712 ** resolve unqualified table references.
6714 ** ^The third and fourth parameters to this function are the table and column
6715 ** name of the desired column, respectively.
6717 ** ^Metadata is returned by writing to the memory locations passed as the 5th
6718 ** and subsequent parameters to this function. ^Any of these arguments may be
6719 ** NULL, in which case the corresponding element of metadata is omitted.
6722 ** <table border="1">
6723 ** <tr><th> Parameter <th> Output<br>Type <th> Description
6725 ** <tr><td> 5th <td> const char* <td> Data type
6726 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6727 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6728 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6729 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6733 ** ^The memory pointed to by the character pointers returned for the
6734 ** declaration type and collation sequence is valid until the next
6735 ** call to any SQLite API function.
6737 ** ^If the specified table is actually a view, an [error code] is returned.
6739 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6740 ** is not a [WITHOUT ROWID] table and an
6741 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6742 ** parameters are set for the explicitly declared column. ^(If there is no
6743 ** [INTEGER PRIMARY KEY] column, then the outputs
6744 ** for the [rowid] are set as follows:
6747 ** data type: "INTEGER"
6748 ** collation sequence: "BINARY"
6751 ** auto increment: 0
6754 ** ^This function causes all database schemas to be read from disk and
6755 ** parsed, if that has not already been done, and returns an error if
6756 ** any errors are encountered while loading the schema.
6758 SQLITE_API int sqlite3_table_column_metadata(
6759 sqlite3 *db, /* Connection handle */
6760 const char *zDbName, /* Database name or NULL */
6761 const char *zTableName, /* Table name */
6762 const char *zColumnName, /* Column name */
6763 char const **pzDataType, /* OUTPUT: Declared data type */
6764 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6765 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6766 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6767 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6771 ** CAPI3REF: Load An Extension
6774 ** ^This interface loads an SQLite extension library from the named file.
6776 ** ^The sqlite3_load_extension() interface attempts to load an
6777 ** [SQLite extension] library contained in the file zFile. If
6778 ** the file cannot be loaded directly, attempts are made to load
6779 ** with various operating-system specific extensions added.
6780 ** So for example, if "samplelib" cannot be loaded, then names like
6781 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6784 ** ^The entry point is zProc.
6785 ** ^(zProc may be 0, in which case SQLite will try to come up with an
6786 ** entry point name on its own. It first tries "sqlite3_extension_init".
6787 ** If that does not work, it constructs a name "sqlite3_X_init" where the
6788 ** X is consists of the lower-case equivalent of all ASCII alphabetic
6789 ** characters in the filename from the last "/" to the first following
6790 ** "." and omitting any initial "lib".)^
6791 ** ^The sqlite3_load_extension() interface returns
6792 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6793 ** ^If an error occurs and pzErrMsg is not 0, then the
6794 ** [sqlite3_load_extension()] interface shall attempt to
6795 ** fill *pzErrMsg with error message text stored in memory
6796 ** obtained from [sqlite3_malloc()]. The calling function
6797 ** should free this memory by calling [sqlite3_free()].
6799 ** ^Extension loading must be enabled using
6800 ** [sqlite3_enable_load_extension()] or
6801 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6802 ** prior to calling this API,
6803 ** otherwise an error will be returned.
6805 ** <b>Security warning:</b> It is recommended that the
6806 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6807 ** interface. The use of the [sqlite3_enable_load_extension()] interface
6808 ** should be avoided. This will keep the SQL function [load_extension()]
6809 ** disabled and prevent SQL injections from giving attackers
6810 ** access to extension loading capabilities.
6812 ** See also the [load_extension() SQL function].
6814 SQLITE_API int sqlite3_load_extension(
6815 sqlite3 *db, /* Load the extension into this database connection */
6816 const char *zFile, /* Name of the shared library containing extension */
6817 const char *zProc, /* Entry point. Derived from zFile if 0 */
6818 char **pzErrMsg /* Put error message here if not 0 */
6822 ** CAPI3REF: Enable Or Disable Extension Loading
6825 ** ^So as not to open security holes in older applications that are
6826 ** unprepared to deal with [extension loading], and as a means of disabling
6827 ** [extension loading] while evaluating user-entered SQL, the following API
6828 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6830 ** ^Extension loading is off by default.
6831 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6832 ** to turn extension loading on and call it with onoff==0 to turn
6833 ** it back off again.
6835 ** ^This interface enables or disables both the C-API
6836 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
6837 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6838 ** to enable or disable only the C-API.)^
6840 ** <b>Security warning:</b> It is recommended that extension loading
6841 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6842 ** rather than this interface, so the [load_extension()] SQL function
6843 ** remains disabled. This will prevent SQL injections from giving attackers
6844 ** access to extension loading capabilities.
6846 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6849 ** CAPI3REF: Automatically Load Statically Linked Extensions
6851 ** ^This interface causes the xEntryPoint() function to be invoked for
6852 ** each new [database connection] that is created. The idea here is that
6853 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6854 ** that is to be automatically loaded into all new database connections.
6856 ** ^(Even though the function prototype shows that xEntryPoint() takes
6857 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
6858 ** arguments and expects an integer result as if the signature of the
6859 ** entry point where as follows:
6861 ** <blockquote><pre>
6862 ** int xEntryPoint(
6863 ** sqlite3 *db,
6864 ** const char **pzErrMsg,
6865 ** const struct sqlite3_api_routines *pThunk
6867 ** </pre></blockquote>)^
6869 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6870 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6871 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6872 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6873 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6874 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6875 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6877 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6878 ** on the list of automatic extensions is a harmless no-op. ^No entry point
6879 ** will be called more than once for each database connection that is opened.
6881 ** See also: [sqlite3_reset_auto_extension()]
6882 ** and [sqlite3_cancel_auto_extension()]
6884 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6887 ** CAPI3REF: Cancel Automatic Extension Loading
6889 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6890 ** initialization routine X that was registered using a prior call to
6891 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6892 ** routine returns 1 if initialization routine X was successfully
6893 ** unregistered and it returns 0 if X was not on the list of initialization
6896 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6899 ** CAPI3REF: Reset Automatic Extension Loading
6901 ** ^This interface disables all automatic extensions previously
6902 ** registered using [sqlite3_auto_extension()].
6904 SQLITE_API void sqlite3_reset_auto_extension(void);
6907 ** The interface to the virtual-table mechanism is currently considered
6908 ** to be experimental. The interface might change in incompatible ways.
6909 ** If this is a problem for you, do not use the interface at this time.
6911 ** When the virtual-table mechanism stabilizes, we will declare the
6912 ** interface fixed, support it indefinitely, and remove this comment.
6916 ** Structures used by the virtual table interface
6918 typedef struct sqlite3_vtab sqlite3_vtab;
6919 typedef struct sqlite3_index_info sqlite3_index_info;
6920 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6921 typedef struct sqlite3_module sqlite3_module;
6924 ** CAPI3REF: Virtual Table Object
6925 ** KEYWORDS: sqlite3_module {virtual table module}
6927 ** This structure, sometimes called a "virtual table module",
6928 ** defines the implementation of a [virtual table].
6929 ** This structure consists mostly of methods for the module.
6931 ** ^A virtual table module is created by filling in a persistent
6932 ** instance of this structure and passing a pointer to that instance
6933 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6934 ** ^The registration remains valid until it is replaced by a different
6935 ** module or until the [database connection] closes. The content
6936 ** of this structure must not change while it is registered with
6937 ** any database connection.
6939 struct sqlite3_module {
6941 int (*xCreate)(sqlite3*, void *pAux,
6942 int argc, const char *const*argv,
6943 sqlite3_vtab **ppVTab, char**);
6944 int (*xConnect)(sqlite3*, void *pAux,
6945 int argc, const char *const*argv,
6946 sqlite3_vtab **ppVTab, char**);
6947 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6948 int (*xDisconnect)(sqlite3_vtab *pVTab);
6949 int (*xDestroy)(sqlite3_vtab *pVTab);
6950 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6951 int (*xClose)(sqlite3_vtab_cursor*);
6952 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6953 int argc, sqlite3_value **argv);
6954 int (*xNext)(sqlite3_vtab_cursor*);
6955 int (*xEof)(sqlite3_vtab_cursor*);
6956 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6957 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6958 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6959 int (*xBegin)(sqlite3_vtab *pVTab);
6960 int (*xSync)(sqlite3_vtab *pVTab);
6961 int (*xCommit)(sqlite3_vtab *pVTab);
6962 int (*xRollback)(sqlite3_vtab *pVTab);
6963 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6964 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6966 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6967 /* The methods above are in version 1 of the sqlite_module object. Those
6968 ** below are for version 2 and greater. */
6969 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6970 int (*xRelease)(sqlite3_vtab *pVTab, int);
6971 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6972 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6973 ** Those below are for version 3 and greater. */
6974 int (*xShadowName)(const char*);
6978 ** CAPI3REF: Virtual Table Indexing Information
6979 ** KEYWORDS: sqlite3_index_info
6981 ** The sqlite3_index_info structure and its substructures is used as part
6982 ** of the [virtual table] interface to
6983 ** pass information into and receive the reply from the [xBestIndex]
6984 ** method of a [virtual table module]. The fields under **Inputs** are the
6985 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
6986 ** results into the **Outputs** fields.
6988 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
6990 ** <blockquote>column OP expr</blockquote>
6992 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
6993 ** stored in aConstraint[].op using one of the
6994 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6995 ** ^(The index of the column is stored in
6996 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6997 ** expr on the right-hand side can be evaluated (and thus the constraint
6998 ** is usable) and false if it cannot.)^
7000 ** ^The optimizer automatically inverts terms of the form "expr OP column"
7001 ** and makes other simplifications to the WHERE clause in an attempt to
7002 ** get as many WHERE clause terms into the form shown above as possible.
7003 ** ^The aConstraint[] array only reports WHERE clause terms that are
7004 ** relevant to the particular virtual table being queried.
7006 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7007 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7009 ** The colUsed field indicates which columns of the virtual table may be
7010 ** required by the current scan. Virtual table columns are numbered from
7011 ** zero in the order in which they appear within the CREATE TABLE statement
7012 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7013 ** the corresponding bit is set within the colUsed mask if the column may be
7014 ** required by SQLite. If the table has at least 64 columns and any column
7015 ** to the right of the first 63 is required, then bit 63 of colUsed is also
7016 ** set. In other words, column iCol may be required if the expression
7017 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7020 ** The [xBestIndex] method must fill aConstraintUsage[] with information
7021 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7022 ** the right-hand side of the corresponding aConstraint[] is evaluated
7023 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7024 ** is true, then the constraint is assumed to be fully handled by the
7025 ** virtual table and might not be checked again by the byte code.)^ ^(The
7026 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7027 ** is left in its default setting of false, the constraint will always be
7028 ** checked separately in byte code. If the omit flag is change to true, then
7029 ** the constraint may or may not be checked in byte code. In other words,
7030 ** when the omit flag is true there is no guarantee that the constraint will
7031 ** not be checked again using byte code.)^
7033 ** ^The idxNum and idxPtr values are recorded and passed into the
7034 ** [xFilter] method.
7035 ** ^[sqlite3_free()] is used to free idxPtr if and only if
7036 ** needToFreeIdxPtr is true.
7038 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7039 ** the correct order to satisfy the ORDER BY clause so that no separate
7040 ** sorting step is required.
7042 ** ^The estimatedCost value is an estimate of the cost of a particular
7043 ** strategy. A cost of N indicates that the cost of the strategy is similar
7044 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7045 ** indicates that the expense of the operation is similar to that of a
7046 ** binary search on a unique indexed field of an SQLite table with N rows.
7048 ** ^The estimatedRows value is an estimate of the number of rows that
7049 ** will be returned by the strategy.
7051 ** The xBestIndex method may optionally populate the idxFlags field with a
7052 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7053 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7054 ** assumes that the strategy may visit at most one row.
7056 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7057 ** SQLite also assumes that if a call to the xUpdate() method is made as
7058 ** part of the same statement to delete or update a virtual table row and the
7059 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7060 ** any database changes. In other words, if the xUpdate() returns
7061 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7062 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7063 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7064 ** the xUpdate method are automatically rolled back by SQLite.
7066 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7067 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7068 ** If a virtual table extension is
7069 ** used with an SQLite version earlier than 3.8.2, the results of attempting
7070 ** to read or write the estimatedRows field are undefined (but are likely
7071 ** to include crashing the application). The estimatedRows field should
7072 ** therefore only be used if [sqlite3_libversion_number()] returns a
7073 ** value greater than or equal to 3008002. Similarly, the idxFlags field
7074 ** was added for [version 3.9.0] ([dateof:3.9.0]).
7075 ** It may therefore only be used if
7076 ** sqlite3_libversion_number() returns a value greater than or equal to
7079 struct sqlite3_index_info {
7081 int nConstraint; /* Number of entries in aConstraint */
7082 struct sqlite3_index_constraint {
7083 int iColumn; /* Column constrained. -1 for ROWID */
7084 unsigned char op; /* Constraint operator */
7085 unsigned char usable; /* True if this constraint is usable */
7086 int iTermOffset; /* Used internally - xBestIndex should ignore */
7087 } *aConstraint; /* Table of WHERE clause constraints */
7088 int nOrderBy; /* Number of terms in the ORDER BY clause */
7089 struct sqlite3_index_orderby {
7090 int iColumn; /* Column number */
7091 unsigned char desc; /* True for DESC. False for ASC. */
7092 } *aOrderBy; /* The ORDER BY clause */
7094 struct sqlite3_index_constraint_usage {
7095 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7096 unsigned char omit; /* Do not code a test for this constraint */
7097 } *aConstraintUsage;
7098 int idxNum; /* Number used to identify the index */
7099 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7100 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7101 int orderByConsumed; /* True if output is already ordered */
7102 double estimatedCost; /* Estimated cost of using this index */
7103 /* Fields below are only available in SQLite 3.8.2 and later */
7104 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7105 /* Fields below are only available in SQLite 3.9.0 and later */
7106 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7107 /* Fields below are only available in SQLite 3.10.0 and later */
7108 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7112 ** CAPI3REF: Virtual Table Scan Flags
7114 ** Virtual table implementations are allowed to set the
7115 ** [sqlite3_index_info].idxFlags field to some combination of
7118 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7121 ** CAPI3REF: Virtual Table Constraint Operator Codes
7123 ** These macros define the allowed values for the
7124 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7125 ** an operator that is part of a constraint term in the wHERE clause of
7126 ** a query that uses a [virtual table].
7128 #define SQLITE_INDEX_CONSTRAINT_EQ 2
7129 #define SQLITE_INDEX_CONSTRAINT_GT 4
7130 #define SQLITE_INDEX_CONSTRAINT_LE 8
7131 #define SQLITE_INDEX_CONSTRAINT_LT 16
7132 #define SQLITE_INDEX_CONSTRAINT_GE 32
7133 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7134 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7135 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7136 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7137 #define SQLITE_INDEX_CONSTRAINT_NE 68
7138 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7139 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7140 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7141 #define SQLITE_INDEX_CONSTRAINT_IS 72
7142 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7145 ** CAPI3REF: Register A Virtual Table Implementation
7148 ** ^These routines are used to register a new [virtual table module] name.
7149 ** ^Module names must be registered before
7150 ** creating a new [virtual table] using the module and before using a
7151 ** preexisting [virtual table] for the module.
7153 ** ^The module name is registered on the [database connection] specified
7154 ** by the first parameter. ^The name of the module is given by the
7155 ** second parameter. ^The third parameter is a pointer to
7156 ** the implementation of the [virtual table module]. ^The fourth
7157 ** parameter is an arbitrary client data pointer that is passed through
7158 ** into the [xCreate] and [xConnect] methods of the virtual table module
7159 ** when a new virtual table is be being created or reinitialized.
7161 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7162 ** is a pointer to a destructor for the pClientData. ^SQLite will
7163 ** invoke the destructor function (if it is not NULL) when SQLite
7164 ** no longer needs the pClientData pointer. ^The destructor will also
7165 ** be invoked if the call to sqlite3_create_module_v2() fails.
7166 ** ^The sqlite3_create_module()
7167 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7170 ** ^If the third parameter (the pointer to the sqlite3_module object) is
7171 ** NULL then no new module is create and any existing modules with the
7172 ** same name are dropped.
7174 ** See also: [sqlite3_drop_modules()]
7176 SQLITE_API int sqlite3_create_module(
7177 sqlite3 *db, /* SQLite connection to register module with */
7178 const char *zName, /* Name of the module */
7179 const sqlite3_module *p, /* Methods for the module */
7180 void *pClientData /* Client data for xCreate/xConnect */
7182 SQLITE_API int sqlite3_create_module_v2(
7183 sqlite3 *db, /* SQLite connection to register module with */
7184 const char *zName, /* Name of the module */
7185 const sqlite3_module *p, /* Methods for the module */
7186 void *pClientData, /* Client data for xCreate/xConnect */
7187 void(*xDestroy)(void*) /* Module destructor function */
7191 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7194 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7195 ** table modules from database connection D except those named on list L.
7196 ** The L parameter must be either NULL or a pointer to an array of pointers
7197 ** to strings where the array is terminated by a single NULL pointer.
7198 ** ^If the L parameter is NULL, then all virtual table modules are removed.
7200 ** See also: [sqlite3_create_module()]
7202 SQLITE_API int sqlite3_drop_modules(
7203 sqlite3 *db, /* Remove modules from this connection */
7204 const char **azKeep /* Except, do not remove the ones named here */
7208 ** CAPI3REF: Virtual Table Instance Object
7209 ** KEYWORDS: sqlite3_vtab
7211 ** Every [virtual table module] implementation uses a subclass
7212 ** of this object to describe a particular instance
7213 ** of the [virtual table]. Each subclass will
7214 ** be tailored to the specific needs of the module implementation.
7215 ** The purpose of this superclass is to define certain fields that are
7216 ** common to all module implementations.
7218 ** ^Virtual tables methods can set an error message by assigning a
7219 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7220 ** take care that any prior string is freed by a call to [sqlite3_free()]
7221 ** prior to assigning a new string to zErrMsg. ^After the error message
7222 ** is delivered up to the client application, the string will be automatically
7223 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7225 struct sqlite3_vtab {
7226 const sqlite3_module *pModule; /* The module for this virtual table */
7227 int nRef; /* Number of open cursors */
7228 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7229 /* Virtual table implementations will typically add additional fields */
7233 ** CAPI3REF: Virtual Table Cursor Object
7234 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7236 ** Every [virtual table module] implementation uses a subclass of the
7237 ** following structure to describe cursors that point into the
7238 ** [virtual table] and are used
7239 ** to loop through the virtual table. Cursors are created using the
7240 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7241 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7242 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7243 ** of the module. Each module implementation will define
7244 ** the content of a cursor structure to suit its own needs.
7246 ** This superclass exists in order to define fields of the cursor that
7247 ** are common to all implementations.
7249 struct sqlite3_vtab_cursor {
7250 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7251 /* Virtual table implementations will typically add additional fields */
7255 ** CAPI3REF: Declare The Schema Of A Virtual Table
7257 ** ^The [xCreate] and [xConnect] methods of a
7258 ** [virtual table module] call this interface
7259 ** to declare the format (the names and datatypes of the columns) of
7260 ** the virtual tables they implement.
7262 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7265 ** CAPI3REF: Overload A Function For A Virtual Table
7268 ** ^(Virtual tables can provide alternative implementations of functions
7269 ** using the [xFindFunction] method of the [virtual table module].
7270 ** But global versions of those functions
7271 ** must exist in order to be overloaded.)^
7273 ** ^(This API makes sure a global version of a function with a particular
7274 ** name and number of parameters exists. If no such function exists
7275 ** before this API is called, a new function is created.)^ ^The implementation
7276 ** of the new function always causes an exception to be thrown. So
7277 ** the new function is not good for anything by itself. Its only
7278 ** purpose is to be a placeholder function that can be overloaded
7279 ** by a [virtual table].
7281 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7284 ** The interface to the virtual-table mechanism defined above (back up
7285 ** to a comment remarkably similar to this one) is currently considered
7286 ** to be experimental. The interface might change in incompatible ways.
7287 ** If this is a problem for you, do not use the interface at this time.
7289 ** When the virtual-table mechanism stabilizes, we will declare the
7290 ** interface fixed, support it indefinitely, and remove this comment.
7294 ** CAPI3REF: A Handle To An Open BLOB
7295 ** KEYWORDS: {BLOB handle} {BLOB handles}
7297 ** An instance of this object represents an open BLOB on which
7298 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7299 ** ^Objects of this type are created by [sqlite3_blob_open()]
7300 ** and destroyed by [sqlite3_blob_close()].
7301 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7302 ** can be used to read or write small subsections of the BLOB.
7303 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7305 typedef struct sqlite3_blob sqlite3_blob;
7308 ** CAPI3REF: Open A BLOB For Incremental I/O
7310 ** CONSTRUCTOR: sqlite3_blob
7312 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7313 ** in row iRow, column zColumn, table zTable in database zDb;
7314 ** in other words, the same BLOB that would be selected by:
7317 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7320 ** ^(Parameter zDb is not the filename that contains the database, but
7321 ** rather the symbolic name of the database. For attached databases, this is
7322 ** the name that appears after the AS keyword in the [ATTACH] statement.
7323 ** For the main database file, the database name is "main". For TEMP
7324 ** tables, the database name is "temp".)^
7326 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7327 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7328 ** read-only access.
7330 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7331 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7332 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7333 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7334 ** on *ppBlob after this function it returns.
7336 ** This function fails with SQLITE_ERROR if any of the following are true:
7338 ** <li> ^(Database zDb does not exist)^,
7339 ** <li> ^(Table zTable does not exist within database zDb)^,
7340 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7341 ** <li> ^(Column zColumn does not exist)^,
7342 ** <li> ^(Row iRow is not present in the table)^,
7343 ** <li> ^(The specified column of row iRow contains a value that is not
7344 ** a TEXT or BLOB value)^,
7345 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7346 ** constraint and the blob is being opened for read/write access)^,
7347 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7348 ** column zColumn is part of a [child key] definition and the blob is
7349 ** being opened for read/write access)^.
7352 ** ^Unless it returns SQLITE_MISUSE, this function sets the
7353 ** [database connection] error code and message accessible via
7354 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7356 ** A BLOB referenced by sqlite3_blob_open() may be read using the
7357 ** [sqlite3_blob_read()] interface and modified by using
7358 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7359 ** different row of the same table using the [sqlite3_blob_reopen()]
7360 ** interface. However, the column, table, or database of a [BLOB handle]
7361 ** cannot be changed after the [BLOB handle] is opened.
7363 ** ^(If the row that a BLOB handle points to is modified by an
7364 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7365 ** then the BLOB handle is marked as "expired".
7366 ** This is true if any column of the row is changed, even a column
7367 ** other than the one the BLOB handle is open on.)^
7368 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7369 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7370 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7371 ** rolled back by the expiration of the BLOB. Such changes will eventually
7372 ** commit if the transaction continues to completion.)^
7374 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7375 ** the opened blob. ^The size of a blob may not be changed by this
7376 ** interface. Use the [UPDATE] SQL command to change the size of a
7379 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7380 ** and the built-in [zeroblob] SQL function may be used to create a
7381 ** zero-filled blob to read or write using the incremental-blob interface.
7383 ** To avoid a resource leak, every open [BLOB handle] should eventually
7384 ** be released by a call to [sqlite3_blob_close()].
7386 ** See also: [sqlite3_blob_close()],
7387 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7388 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7390 SQLITE_API int sqlite3_blob_open(
7394 const char *zColumn,
7397 sqlite3_blob **ppBlob
7401 ** CAPI3REF: Move a BLOB Handle to a New Row
7402 ** METHOD: sqlite3_blob
7404 ** ^This function is used to move an existing [BLOB handle] so that it points
7405 ** to a different row of the same database table. ^The new row is identified
7406 ** by the rowid value passed as the second argument. Only the row can be
7407 ** changed. ^The database, table and column on which the blob handle is open
7408 ** remain the same. Moving an existing [BLOB handle] to a new row is
7409 ** faster than closing the existing handle and opening a new one.
7411 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7412 ** it must exist and there must be either a blob or text value stored in
7413 ** the nominated column.)^ ^If the new row is not present in the table, or if
7414 ** it does not contain a blob or text value, or if another error occurs, an
7415 ** SQLite error code is returned and the blob handle is considered aborted.
7416 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7417 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7418 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7419 ** always returns zero.
7421 ** ^This function sets the database handle error code and message.
7423 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7426 ** CAPI3REF: Close A BLOB Handle
7427 ** DESTRUCTOR: sqlite3_blob
7429 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7430 ** unconditionally. Even if this routine returns an error code, the
7431 ** handle is still closed.)^
7433 ** ^If the blob handle being closed was opened for read-write access, and if
7434 ** the database is in auto-commit mode and there are no other open read-write
7435 ** blob handles or active write statements, the current transaction is
7436 ** committed. ^If an error occurs while committing the transaction, an error
7437 ** code is returned and the transaction rolled back.
7439 ** Calling this function with an argument that is not a NULL pointer or an
7440 ** open blob handle results in undefined behaviour. ^Calling this routine
7441 ** with a null pointer (such as would be returned by a failed call to
7442 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7443 ** is passed a valid open blob handle, the values returned by the
7444 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7446 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7449 ** CAPI3REF: Return The Size Of An Open BLOB
7450 ** METHOD: sqlite3_blob
7452 ** ^Returns the size in bytes of the BLOB accessible via the
7453 ** successfully opened [BLOB handle] in its only argument. ^The
7454 ** incremental blob I/O routines can only read or overwriting existing
7455 ** blob content; they cannot change the size of a blob.
7457 ** This routine only works on a [BLOB handle] which has been created
7458 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7459 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7460 ** to this routine results in undefined and probably undesirable behavior.
7462 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7465 ** CAPI3REF: Read Data From A BLOB Incrementally
7466 ** METHOD: sqlite3_blob
7468 ** ^(This function is used to read data from an open [BLOB handle] into a
7469 ** caller-supplied buffer. N bytes of data are copied into buffer Z
7470 ** from the open BLOB, starting at offset iOffset.)^
7472 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7473 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7474 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
7475 ** ^The size of the blob (and hence the maximum value of N+iOffset)
7476 ** can be determined using the [sqlite3_blob_bytes()] interface.
7478 ** ^An attempt to read from an expired [BLOB handle] fails with an
7479 ** error code of [SQLITE_ABORT].
7481 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7482 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7484 ** This routine only works on a [BLOB handle] which has been created
7485 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7486 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7487 ** to this routine results in undefined and probably undesirable behavior.
7489 ** See also: [sqlite3_blob_write()].
7491 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7494 ** CAPI3REF: Write Data Into A BLOB Incrementally
7495 ** METHOD: sqlite3_blob
7497 ** ^(This function is used to write data into an open [BLOB handle] from a
7498 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
7499 ** into the open BLOB, starting at offset iOffset.)^
7501 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7502 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7503 ** ^Unless SQLITE_MISUSE is returned, this function sets the
7504 ** [database connection] error code and message accessible via
7505 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7507 ** ^If the [BLOB handle] passed as the first argument was not opened for
7508 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7509 ** this function returns [SQLITE_READONLY].
7511 ** This function may only modify the contents of the BLOB; it is
7512 ** not possible to increase the size of a BLOB using this API.
7513 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7514 ** [SQLITE_ERROR] is returned and no data is written. The size of the
7515 ** BLOB (and hence the maximum value of N+iOffset) can be determined
7516 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7517 ** than zero [SQLITE_ERROR] is returned and no data is written.
7519 ** ^An attempt to write to an expired [BLOB handle] fails with an
7520 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7521 ** before the [BLOB handle] expired are not rolled back by the
7522 ** expiration of the handle, though of course those changes might
7523 ** have been overwritten by the statement that expired the BLOB handle
7524 ** or by other independent statements.
7526 ** This routine only works on a [BLOB handle] which has been created
7527 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7528 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7529 ** to this routine results in undefined and probably undesirable behavior.
7531 ** See also: [sqlite3_blob_read()].
7533 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7536 ** CAPI3REF: Virtual File System Objects
7538 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7539 ** that SQLite uses to interact
7540 ** with the underlying operating system. Most SQLite builds come with a
7541 ** single default VFS that is appropriate for the host computer.
7542 ** New VFSes can be registered and existing VFSes can be unregistered.
7543 ** The following interfaces are provided.
7545 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7546 ** ^Names are case sensitive.
7547 ** ^Names are zero-terminated UTF-8 strings.
7548 ** ^If there is no match, a NULL pointer is returned.
7549 ** ^If zVfsName is NULL then the default VFS is returned.
7551 ** ^New VFSes are registered with sqlite3_vfs_register().
7552 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7553 ** ^The same VFS can be registered multiple times without injury.
7554 ** ^To make an existing VFS into the default VFS, register it again
7555 ** with the makeDflt flag set. If two different VFSes with the
7556 ** same name are registered, the behavior is undefined. If a
7557 ** VFS is registered with a name that is NULL or an empty string,
7558 ** then the behavior is undefined.
7560 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7561 ** ^(If the default VFS is unregistered, another VFS is chosen as
7562 ** the default. The choice for the new VFS is arbitrary.)^
7564 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7565 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7566 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7569 ** CAPI3REF: Mutexes
7571 ** The SQLite core uses these routines for thread
7572 ** synchronization. Though they are intended for internal
7573 ** use by SQLite, code that links against SQLite is
7574 ** permitted to use any of these routines.
7576 ** The SQLite source code contains multiple implementations
7577 ** of these mutex routines. An appropriate implementation
7578 ** is selected automatically at compile-time. The following
7579 ** implementations are available in the SQLite core:
7582 ** <li> SQLITE_MUTEX_PTHREADS
7583 ** <li> SQLITE_MUTEX_W32
7584 ** <li> SQLITE_MUTEX_NOOP
7587 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
7588 ** that does no real locking and is appropriate for use in
7589 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7590 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7593 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7594 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7595 ** implementation is included with the library. In this case the
7596 ** application must supply a custom mutex implementation using the
7597 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7598 ** before calling sqlite3_initialize() or any other public sqlite3_
7599 ** function that calls sqlite3_initialize().
7601 ** ^The sqlite3_mutex_alloc() routine allocates a new
7602 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7603 ** routine returns NULL if it is unable to allocate the requested
7604 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
7605 ** integer constants:
7608 ** <li> SQLITE_MUTEX_FAST
7609 ** <li> SQLITE_MUTEX_RECURSIVE
7610 ** <li> SQLITE_MUTEX_STATIC_MAIN
7611 ** <li> SQLITE_MUTEX_STATIC_MEM
7612 ** <li> SQLITE_MUTEX_STATIC_OPEN
7613 ** <li> SQLITE_MUTEX_STATIC_PRNG
7614 ** <li> SQLITE_MUTEX_STATIC_LRU
7615 ** <li> SQLITE_MUTEX_STATIC_PMEM
7616 ** <li> SQLITE_MUTEX_STATIC_APP1
7617 ** <li> SQLITE_MUTEX_STATIC_APP2
7618 ** <li> SQLITE_MUTEX_STATIC_APP3
7619 ** <li> SQLITE_MUTEX_STATIC_VFS1
7620 ** <li> SQLITE_MUTEX_STATIC_VFS2
7621 ** <li> SQLITE_MUTEX_STATIC_VFS3
7624 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7625 ** cause sqlite3_mutex_alloc() to create
7626 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7627 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7628 ** The mutex implementation does not need to make a distinction
7629 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7630 ** not want to. SQLite will only request a recursive mutex in
7631 ** cases where it really needs one. If a faster non-recursive mutex
7632 ** implementation is available on the host platform, the mutex subsystem
7633 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
7635 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7636 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7637 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
7638 ** used by the current version of SQLite. Future versions of SQLite
7639 ** may add additional static mutexes. Static mutexes are for internal
7640 ** use by SQLite only. Applications that use SQLite mutexes should
7641 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7642 ** SQLITE_MUTEX_RECURSIVE.
7644 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7645 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7646 ** returns a different mutex on every call. ^For the static
7647 ** mutex types, the same mutex is returned on every call that has
7648 ** the same type number.
7650 ** ^The sqlite3_mutex_free() routine deallocates a previously
7651 ** allocated dynamic mutex. Attempting to deallocate a static
7652 ** mutex results in undefined behavior.
7654 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7655 ** to enter a mutex. ^If another thread is already within the mutex,
7656 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7657 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7658 ** upon successful entry. ^(Mutexes created using
7659 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7660 ** In such cases, the
7661 ** mutex must be exited an equal number of times before another thread
7662 ** can enter.)^ If the same thread tries to enter any mutex other
7663 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7665 ** ^(Some systems (for example, Windows 95) do not support the operation
7666 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7667 ** will always return SQLITE_BUSY. The SQLite core only ever uses
7668 ** sqlite3_mutex_try() as an optimization so this is acceptable
7671 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
7672 ** previously entered by the same thread. The behavior
7673 ** is undefined if the mutex is not currently entered by the
7674 ** calling thread or is not currently allocated.
7676 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7677 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7678 ** behave as no-ops.
7680 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7682 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7683 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7684 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7685 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7686 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7689 ** CAPI3REF: Mutex Methods Object
7691 ** An instance of this structure defines the low-level routines
7692 ** used to allocate and use mutexes.
7694 ** Usually, the default mutex implementations provided by SQLite are
7695 ** sufficient, however the application has the option of substituting a custom
7696 ** implementation for specialized deployments or systems for which SQLite
7697 ** does not provide a suitable implementation. In this case, the application
7698 ** creates and populates an instance of this structure to pass
7699 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7700 ** Additionally, an instance of this structure can be used as an
7701 ** output variable when querying the system for the current mutex
7702 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7704 ** ^The xMutexInit method defined by this structure is invoked as
7705 ** part of system initialization by the sqlite3_initialize() function.
7706 ** ^The xMutexInit routine is called by SQLite exactly once for each
7707 ** effective call to [sqlite3_initialize()].
7709 ** ^The xMutexEnd method defined by this structure is invoked as
7710 ** part of system shutdown by the sqlite3_shutdown() function. The
7711 ** implementation of this method is expected to release all outstanding
7712 ** resources obtained by the mutex methods implementation, especially
7713 ** those obtained by the xMutexInit method. ^The xMutexEnd()
7714 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7716 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7717 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7718 ** xMutexNotheld) implement the following interfaces (respectively):
7721 ** <li> [sqlite3_mutex_alloc()] </li>
7722 ** <li> [sqlite3_mutex_free()] </li>
7723 ** <li> [sqlite3_mutex_enter()] </li>
7724 ** <li> [sqlite3_mutex_try()] </li>
7725 ** <li> [sqlite3_mutex_leave()] </li>
7726 ** <li> [sqlite3_mutex_held()] </li>
7727 ** <li> [sqlite3_mutex_notheld()] </li>
7730 ** The only difference is that the public sqlite3_XXX functions enumerated
7731 ** above silently ignore any invocations that pass a NULL pointer instead
7732 ** of a valid mutex handle. The implementations of the methods defined
7733 ** by this structure are not required to handle this case. The results
7734 ** of passing a NULL pointer instead of a valid mutex handle are undefined
7735 ** (i.e. it is acceptable to provide an implementation that segfaults if
7736 ** it is passed a NULL pointer).
7738 ** The xMutexInit() method must be threadsafe. It must be harmless to
7739 ** invoke xMutexInit() multiple times within the same process and without
7740 ** intervening calls to xMutexEnd(). Second and subsequent calls to
7741 ** xMutexInit() must be no-ops.
7743 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7744 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7745 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7746 ** memory allocation for a fast or recursive mutex.
7748 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7749 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7750 ** If xMutexInit fails in any way, it is expected to clean up after itself
7751 ** prior to returning.
7753 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7754 struct sqlite3_mutex_methods {
7755 int (*xMutexInit)(void);
7756 int (*xMutexEnd)(void);
7757 sqlite3_mutex *(*xMutexAlloc)(int);
7758 void (*xMutexFree)(sqlite3_mutex *);
7759 void (*xMutexEnter)(sqlite3_mutex *);
7760 int (*xMutexTry)(sqlite3_mutex *);
7761 void (*xMutexLeave)(sqlite3_mutex *);
7762 int (*xMutexHeld)(sqlite3_mutex *);
7763 int (*xMutexNotheld)(sqlite3_mutex *);
7767 ** CAPI3REF: Mutex Verification Routines
7769 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7770 ** are intended for use inside assert() statements. The SQLite core
7771 ** never uses these routines except inside an assert() and applications
7772 ** are advised to follow the lead of the core. The SQLite core only
7773 ** provides implementations for these routines when it is compiled
7774 ** with the SQLITE_DEBUG flag. External mutex implementations
7775 ** are only required to provide these routines if SQLITE_DEBUG is
7776 ** defined and if NDEBUG is not defined.
7778 ** These routines should return true if the mutex in their argument
7779 ** is held or not held, respectively, by the calling thread.
7781 ** The implementation is not required to provide versions of these
7782 ** routines that actually work. If the implementation does not provide working
7783 ** versions of these routines, it should at least provide stubs that always
7784 ** return true so that one does not get spurious assertion failures.
7786 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
7787 ** the routine should return 1. This seems counter-intuitive since
7788 ** clearly the mutex cannot be held if it does not exist. But
7789 ** the reason the mutex does not exist is because the build is not
7790 ** using mutexes. And we do not want the assert() containing the
7791 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
7792 ** the appropriate thing to do. The sqlite3_mutex_notheld()
7793 ** interface should also return 1 when given a NULL pointer.
7796 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7797 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7801 ** CAPI3REF: Mutex Types
7803 ** The [sqlite3_mutex_alloc()] interface takes a single argument
7804 ** which is one of these integer constants.
7806 ** The set of static mutexes may change from one SQLite release to the
7807 ** next. Applications that override the built-in mutex logic must be
7808 ** prepared to accommodate additional static mutexes.
7810 #define SQLITE_MUTEX_FAST 0
7811 #define SQLITE_MUTEX_RECURSIVE 1
7812 #define SQLITE_MUTEX_STATIC_MAIN 2
7813 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7814 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7815 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7816 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7817 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7818 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7819 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7820 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7821 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7822 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7823 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7824 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7825 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7827 /* Legacy compatibility: */
7828 #define SQLITE_MUTEX_STATIC_MASTER 2
7832 ** CAPI3REF: Retrieve the mutex for a database connection
7835 ** ^This interface returns a pointer the [sqlite3_mutex] object that
7836 ** serializes access to the [database connection] given in the argument
7837 ** when the [threading mode] is Serialized.
7838 ** ^If the [threading mode] is Single-thread or Multi-thread then this
7839 ** routine returns a NULL pointer.
7841 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7844 ** CAPI3REF: Low-Level Control Of Database Files
7846 ** KEYWORDS: {file control}
7848 ** ^The [sqlite3_file_control()] interface makes a direct call to the
7849 ** xFileControl method for the [sqlite3_io_methods] object associated
7850 ** with a particular database identified by the second argument. ^The
7851 ** name of the database is "main" for the main database or "temp" for the
7852 ** TEMP database, or the name that appears after the AS keyword for
7853 ** databases that are added using the [ATTACH] SQL command.
7854 ** ^A NULL pointer can be used in place of "main" to refer to the
7855 ** main database file.
7856 ** ^The third and fourth parameters to this routine
7857 ** are passed directly through to the second and third parameters of
7858 ** the xFileControl method. ^The return value of the xFileControl
7859 ** method becomes the return value of this routine.
7861 ** A few opcodes for [sqlite3_file_control()] are handled directly
7862 ** by the SQLite core and never invoke the
7863 ** sqlite3_io_methods.xFileControl method.
7864 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7865 ** a pointer to the underlying [sqlite3_file] object to be written into
7866 ** the space pointed to by the 4th parameter. The
7867 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7868 ** the [sqlite3_file] object associated with the journal file instead of
7869 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7870 ** a pointer to the underlying [sqlite3_vfs] object for the file.
7871 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7874 ** ^If the second parameter (zDbName) does not match the name of any
7875 ** open database file, then SQLITE_ERROR is returned. ^This error
7876 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
7877 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
7878 ** also return SQLITE_ERROR. There is no way to distinguish between
7879 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7880 ** xFileControl method.
7882 ** See also: [file control opcodes]
7884 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7887 ** CAPI3REF: Testing Interface
7889 ** ^The sqlite3_test_control() interface is used to read out internal
7890 ** state of SQLite and to inject faults into SQLite for testing
7891 ** purposes. ^The first parameter is an operation code that determines
7892 ** the number, meaning, and operation of all subsequent parameters.
7894 ** This interface is not for use by applications. It exists solely
7895 ** for verifying the correct operation of the SQLite library. Depending
7896 ** on how the SQLite library is compiled, this interface might not exist.
7898 ** The details of the operation codes, their meanings, the parameters
7899 ** they take, and what they do are all subject to change without notice.
7900 ** Unlike most of the SQLite API, this function is not guaranteed to
7901 ** operate consistently from one release to the next.
7903 SQLITE_API int sqlite3_test_control(int op, ...);
7906 ** CAPI3REF: Testing Interface Operation Codes
7908 ** These constants are the valid operation code parameters used
7909 ** as the first argument to [sqlite3_test_control()].
7911 ** These parameters and their meanings are subject to change
7912 ** without notice. These values are for testing purposes only.
7913 ** Applications should not use any of these parameters or the
7914 ** [sqlite3_test_control()] interface.
7916 #define SQLITE_TESTCTRL_FIRST 5
7917 #define SQLITE_TESTCTRL_PRNG_SAVE 5
7918 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
7919 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
7920 #define SQLITE_TESTCTRL_BITVEC_TEST 8
7921 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
7922 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7923 #define SQLITE_TESTCTRL_PENDING_BYTE 11
7924 #define SQLITE_TESTCTRL_ASSERT 12
7925 #define SQLITE_TESTCTRL_ALWAYS 13
7926 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
7927 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7928 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7929 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7930 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7931 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7932 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7933 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7934 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7935 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7936 #define SQLITE_TESTCTRL_BYTEORDER 22
7937 #define SQLITE_TESTCTRL_ISINIT 23
7938 #define SQLITE_TESTCTRL_SORTER_MMAP 24
7939 #define SQLITE_TESTCTRL_IMPOSTER 25
7940 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7941 #define SQLITE_TESTCTRL_RESULT_INTREAL 27
7942 #define SQLITE_TESTCTRL_PRNG_SEED 28
7943 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
7944 #define SQLITE_TESTCTRL_SEEK_COUNT 30
7945 #define SQLITE_TESTCTRL_TRACEFLAGS 31
7946 #define SQLITE_TESTCTRL_TUNE 32
7947 #define SQLITE_TESTCTRL_LAST 32 /* Largest TESTCTRL */
7950 ** CAPI3REF: SQL Keyword Checking
7952 ** These routines provide access to the set of SQL language keywords
7953 ** recognized by SQLite. Applications can uses these routines to determine
7954 ** whether or not a specific identifier needs to be escaped (for example,
7955 ** by enclosing in double-quotes) so as not to confuse the parser.
7957 ** The sqlite3_keyword_count() interface returns the number of distinct
7958 ** keywords understood by SQLite.
7960 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7961 ** makes *Z point to that keyword expressed as UTF8 and writes the number
7962 ** of bytes in the keyword into *L. The string that *Z points to is not
7963 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7964 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7965 ** or L are NULL or invalid pointers then calls to
7966 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7968 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7969 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7970 ** if it is and zero if not.
7972 ** The parser used by SQLite is forgiving. It is often possible to use
7973 ** a keyword as an identifier as long as such use does not result in a
7974 ** parsing ambiguity. For example, the statement
7975 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7976 ** creates a new table named "BEGIN" with three columns named
7977 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7978 ** using keywords as identifiers. Common techniques used to avoid keyword
7979 ** name collisions include:
7981 ** <li> Put all identifier names inside double-quotes. This is the official
7982 ** SQL way to escape identifier names.
7983 ** <li> Put identifier names inside [...]. This is not standard SQL,
7984 ** but it is what SQL Server does and so lots of programmers use this
7986 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7988 ** <li> Include a digit somewhere in every identifier name.
7991 ** Note that the number of keywords understood by SQLite can depend on
7992 ** compile-time options. For example, "VACUUM" is not a keyword if
7993 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7994 ** new keywords may be added to future releases of SQLite.
7996 SQLITE_API int sqlite3_keyword_count(void);
7997 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7998 SQLITE_API int sqlite3_keyword_check(const char*,int);
8001 ** CAPI3REF: Dynamic String Object
8002 ** KEYWORDS: {dynamic string}
8004 ** An instance of the sqlite3_str object contains a dynamically-sized
8005 ** string under construction.
8007 ** The lifecycle of an sqlite3_str object is as follows:
8009 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8010 ** <li> ^Text is appended to the sqlite3_str object using various
8011 ** methods, such as [sqlite3_str_appendf()].
8012 ** <li> ^The sqlite3_str object is destroyed and the string it created
8013 ** is returned using the [sqlite3_str_finish()] interface.
8016 typedef struct sqlite3_str sqlite3_str;
8019 ** CAPI3REF: Create A New Dynamic String Object
8020 ** CONSTRUCTOR: sqlite3_str
8022 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8023 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8024 ** [sqlite3_str_new()] must be freed by a subsequent call to
8025 ** [sqlite3_str_finish(X)].
8027 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8028 ** valid [sqlite3_str] object, though in the event of an out-of-memory
8029 ** error the returned object might be a special singleton that will
8030 ** silently reject new text, always return SQLITE_NOMEM from
8031 ** [sqlite3_str_errcode()], always return 0 for
8032 ** [sqlite3_str_length()], and always return NULL from
8033 ** [sqlite3_str_finish(X)]. It is always safe to use the value
8034 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8035 ** to any of the other [sqlite3_str] methods.
8037 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8038 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8039 ** length of the string contained in the [sqlite3_str] object will be
8040 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8041 ** of [SQLITE_MAX_LENGTH].
8043 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8046 ** CAPI3REF: Finalize A Dynamic String
8047 ** DESTRUCTOR: sqlite3_str
8049 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8050 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8051 ** that contains the constructed string. The calling application should
8052 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8053 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8054 ** errors were encountered during construction of the string. ^The
8055 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8056 ** string in [sqlite3_str] object X is zero bytes long.
8058 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8061 ** CAPI3REF: Add Content To A Dynamic String
8062 ** METHOD: sqlite3_str
8064 ** These interfaces add content to an sqlite3_str object previously obtained
8065 ** from [sqlite3_str_new()].
8067 ** ^The [sqlite3_str_appendf(X,F,...)] and
8068 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8069 ** functionality of SQLite to append formatted text onto the end of
8070 ** [sqlite3_str] object X.
8072 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8073 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8074 ** S must contain at least N non-zero bytes of content. To append a
8075 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8078 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8079 ** zero-terminated string S onto the end of [sqlite3_str] object X.
8081 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8082 ** single-byte character C onto the end of [sqlite3_str] object X.
8083 ** ^This method can be used, for example, to add whitespace indentation.
8085 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8086 ** inside [sqlite3_str] object X back to zero bytes in length.
8088 ** These methods do not return a result code. ^If an error occurs, that fact
8089 ** is recorded in the [sqlite3_str] object and can be recovered by a
8090 ** subsequent call to [sqlite3_str_errcode(X)].
8092 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8093 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8094 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8095 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8096 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8097 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8100 ** CAPI3REF: Status Of A Dynamic String
8101 ** METHOD: sqlite3_str
8103 ** These interfaces return the current status of an [sqlite3_str] object.
8105 ** ^If any prior errors have occurred while constructing the dynamic string
8106 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8107 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8108 ** [SQLITE_NOMEM] following any out-of-memory error, or
8109 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8110 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8112 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8113 ** of the dynamic string under construction in [sqlite3_str] object X.
8114 ** ^The length returned by [sqlite3_str_length(X)] does not include the
8115 ** zero-termination byte.
8117 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8118 ** content of the dynamic string under construction in X. The value
8119 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8120 ** and might be freed or altered by any subsequent method on the same
8121 ** [sqlite3_str] object. Applications must not used the pointer returned
8122 ** [sqlite3_str_value(X)] after any subsequent method call on the same
8123 ** object. ^Applications may change the content of the string returned
8124 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8125 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8126 ** write any byte after any subsequent sqlite3_str method call.
8128 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8129 SQLITE_API int sqlite3_str_length(sqlite3_str*);
8130 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8133 ** CAPI3REF: SQLite Runtime Status
8135 ** ^These interfaces are used to retrieve runtime status information
8136 ** about the performance of SQLite, and optionally to reset various
8137 ** highwater marks. ^The first argument is an integer code for
8138 ** the specific parameter to measure. ^(Recognized integer codes
8139 ** are of the form [status parameters | SQLITE_STATUS_...].)^
8140 ** ^The current value of the parameter is returned into *pCurrent.
8141 ** ^The highest recorded value is returned in *pHighwater. ^If the
8142 ** resetFlag is true, then the highest record value is reset after
8143 ** *pHighwater is written. ^(Some parameters do not record the highest
8144 ** value. For those parameters
8145 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8146 ** ^(Other parameters record only the highwater mark and not the current
8147 ** value. For these latter parameters nothing is written into *pCurrent.)^
8149 ** ^The sqlite3_status() and sqlite3_status64() routines return
8150 ** SQLITE_OK on success and a non-zero [error code] on failure.
8152 ** If either the current value or the highwater mark is too large to
8153 ** be represented by a 32-bit integer, then the values returned by
8154 ** sqlite3_status() are undefined.
8156 ** See also: [sqlite3_db_status()]
8158 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8159 SQLITE_API int sqlite3_status64(
8161 sqlite3_int64 *pCurrent,
8162 sqlite3_int64 *pHighwater,
8168 ** CAPI3REF: Status Parameters
8169 ** KEYWORDS: {status parameters}
8171 ** These integer constants designate various run-time status parameters
8172 ** that can be returned by [sqlite3_status()].
8175 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8176 ** <dd>This parameter is the current amount of memory checked out
8177 ** using [sqlite3_malloc()], either directly or indirectly. The
8178 ** figure includes calls made to [sqlite3_malloc()] by the application
8179 ** and internal memory usage by the SQLite library. Auxiliary page-cache
8180 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8181 ** this parameter. The amount returned is the sum of the allocation
8182 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8184 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8185 ** <dd>This parameter records the largest memory allocation request
8186 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8187 ** internal equivalents). Only the value returned in the
8188 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8189 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8191 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8192 ** <dd>This parameter records the number of separate memory allocations
8193 ** currently checked out.</dd>)^
8195 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8196 ** <dd>This parameter returns the number of pages used out of the
8197 ** [pagecache memory allocator] that was configured using
8198 ** [SQLITE_CONFIG_PAGECACHE]. The
8199 ** value returned is in pages, not in bytes.</dd>)^
8201 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8202 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8203 ** <dd>This parameter returns the number of bytes of page cache
8204 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8205 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8206 ** returned value includes allocations that overflowed because they
8207 ** where too large (they were larger than the "sz" parameter to
8208 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8209 ** no space was left in the page cache.</dd>)^
8211 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8212 ** <dd>This parameter records the largest memory allocation request
8213 ** handed to the [pagecache memory allocator]. Only the value returned in the
8214 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8215 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8217 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8218 ** <dd>No longer used.</dd>
8220 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8221 ** <dd>No longer used.</dd>
8223 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8224 ** <dd>No longer used.</dd>
8226 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8227 ** <dd>The *pHighwater parameter records the deepest parser stack.
8228 ** The *pCurrent value is undefined. The *pHighwater value is only
8229 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8232 ** New status parameters may be added from time to time.
8234 #define SQLITE_STATUS_MEMORY_USED 0
8235 #define SQLITE_STATUS_PAGECACHE_USED 1
8236 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8237 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8238 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8239 #define SQLITE_STATUS_MALLOC_SIZE 5
8240 #define SQLITE_STATUS_PARSER_STACK 6
8241 #define SQLITE_STATUS_PAGECACHE_SIZE 7
8242 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8243 #define SQLITE_STATUS_MALLOC_COUNT 9
8246 ** CAPI3REF: Database Connection Status
8249 ** ^This interface is used to retrieve runtime status information
8250 ** about a single [database connection]. ^The first argument is the
8251 ** database connection object to be interrogated. ^The second argument
8252 ** is an integer constant, taken from the set of
8253 ** [SQLITE_DBSTATUS options], that
8254 ** determines the parameter to interrogate. The set of
8255 ** [SQLITE_DBSTATUS options] is likely
8256 ** to grow in future releases of SQLite.
8258 ** ^The current value of the requested parameter is written into *pCur
8259 ** and the highest instantaneous value is written into *pHiwtr. ^If
8260 ** the resetFlg is true, then the highest instantaneous value is
8261 ** reset back down to the current value.
8263 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8264 ** non-zero [error code] on failure.
8266 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8268 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8271 ** CAPI3REF: Status Parameters for database connections
8272 ** KEYWORDS: {SQLITE_DBSTATUS options}
8274 ** These constants are the available integer "verbs" that can be passed as
8275 ** the second argument to the [sqlite3_db_status()] interface.
8277 ** New verbs may be added in future releases of SQLite. Existing verbs
8278 ** might be discontinued. Applications should check the return code from
8279 ** [sqlite3_db_status()] to make sure that the call worked.
8280 ** The [sqlite3_db_status()] interface will return a non-zero error code
8281 ** if a discontinued or unsupported verb is invoked.
8284 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8285 ** <dd>This parameter returns the number of lookaside memory slots currently
8286 ** checked out.</dd>)^
8288 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8289 ** <dd>This parameter returns the number of malloc attempts that were
8290 ** satisfied using lookaside memory. Only the high-water value is meaningful;
8291 ** the current value is always zero.)^
8293 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8294 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8295 ** <dd>This parameter returns the number malloc attempts that might have
8296 ** been satisfied using lookaside memory but failed due to the amount of
8297 ** memory requested being larger than the lookaside slot size.
8298 ** Only the high-water value is meaningful;
8299 ** the current value is always zero.)^
8301 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8302 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8303 ** <dd>This parameter returns the number malloc attempts that might have
8304 ** been satisfied using lookaside memory but failed due to all lookaside
8305 ** memory already being in use.
8306 ** Only the high-water value is meaningful;
8307 ** the current value is always zero.)^
8309 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8310 ** <dd>This parameter returns the approximate number of bytes of heap
8311 ** memory used by all pager caches associated with the database connection.)^
8312 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8314 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8315 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8316 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8317 ** pager cache is shared between two or more connections the bytes of heap
8318 ** memory used by that pager cache is divided evenly between the attached
8319 ** connections.)^ In other words, if none of the pager caches associated
8320 ** with the database connection are shared, this request returns the same
8321 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8322 ** shared, the value returned by this call will be smaller than that returned
8323 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8324 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8326 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8327 ** <dd>This parameter returns the approximate number of bytes of heap
8328 ** memory used to store the schema for all databases associated
8329 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8330 ** ^The full amount of memory used by the schemas is reported, even if the
8331 ** schema memory is shared with other database connections due to
8332 ** [shared cache mode] being enabled.
8333 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8335 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8336 ** <dd>This parameter returns the approximate number of bytes of heap
8337 ** and lookaside memory used by all prepared statements associated with
8338 ** the database connection.)^
8339 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8342 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8343 ** <dd>This parameter returns the number of pager cache hits that have
8344 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8348 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8349 ** <dd>This parameter returns the number of pager cache misses that have
8350 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8354 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8355 ** <dd>This parameter returns the number of dirty cache entries that have
8356 ** been written to disk. Specifically, the number of pages written to the
8357 ** wal file in wal mode databases, or the number of pages written to the
8358 ** database file in rollback mode databases. Any pages written as part of
8359 ** transaction rollback or database recovery operations are not included.
8360 ** If an IO or other error occurs while writing a page to disk, the effect
8361 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8362 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8365 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8366 ** <dd>This parameter returns the number of dirty cache entries that have
8367 ** been written to disk in the middle of a transaction due to the page
8368 ** cache overflowing. Transactions are more efficient if they are written
8369 ** to disk all at once. When pages spill mid-transaction, that introduces
8370 ** additional overhead. This parameter can be used help identify
8371 ** inefficiencies that can be resolved by increasing the cache size.
8374 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8375 ** <dd>This parameter returns zero for the current value if and only if
8376 ** all foreign key constraints (deferred or immediate) have been
8377 ** resolved.)^ ^The highwater mark is always 0.
8381 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8382 #define SQLITE_DBSTATUS_CACHE_USED 1
8383 #define SQLITE_DBSTATUS_SCHEMA_USED 2
8384 #define SQLITE_DBSTATUS_STMT_USED 3
8385 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8386 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8387 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8388 #define SQLITE_DBSTATUS_CACHE_HIT 7
8389 #define SQLITE_DBSTATUS_CACHE_MISS 8
8390 #define SQLITE_DBSTATUS_CACHE_WRITE 9
8391 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
8392 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8393 #define SQLITE_DBSTATUS_CACHE_SPILL 12
8394 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8398 ** CAPI3REF: Prepared Statement Status
8399 ** METHOD: sqlite3_stmt
8401 ** ^(Each prepared statement maintains various
8402 ** [SQLITE_STMTSTATUS counters] that measure the number
8403 ** of times it has performed specific operations.)^ These counters can
8404 ** be used to monitor the performance characteristics of the prepared
8405 ** statements. For example, if the number of table steps greatly exceeds
8406 ** the number of table searches or result rows, that would tend to indicate
8407 ** that the prepared statement is using a full table scan rather than
8410 ** ^(This interface is used to retrieve and reset counter values from
8411 ** a [prepared statement]. The first argument is the prepared statement
8412 ** object to be interrogated. The second argument
8413 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8414 ** to be interrogated.)^
8415 ** ^The current value of the requested counter is returned.
8416 ** ^If the resetFlg is true, then the counter is reset to zero after this
8417 ** interface call returns.
8419 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
8421 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8424 ** CAPI3REF: Status Parameters for prepared statements
8425 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8427 ** These preprocessor macros define integer codes that name counter
8428 ** values associated with the [sqlite3_stmt_status()] interface.
8429 ** The meanings of the various counters are as follows:
8432 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8433 ** <dd>^This is the number of times that SQLite has stepped forward in
8434 ** a table as part of a full table scan. Large numbers for this counter
8435 ** may indicate opportunities for performance improvement through
8436 ** careful use of indices.</dd>
8438 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8439 ** <dd>^This is the number of sort operations that have occurred.
8440 ** A non-zero value in this counter may indicate an opportunity to
8441 ** improvement performance through careful use of indices.</dd>
8443 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8444 ** <dd>^This is the number of rows inserted into transient indices that
8445 ** were created automatically in order to help joins run faster.
8446 ** A non-zero value in this counter may indicate an opportunity to
8447 ** improvement performance by adding permanent indices that do not
8448 ** need to be reinitialized each time the statement is run.</dd>
8450 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8451 ** <dd>^This is the number of virtual machine operations executed
8452 ** by the prepared statement if that number is less than or equal
8453 ** to 2147483647. The number of virtual machine operations can be
8454 ** used as a proxy for the total work done by the prepared statement.
8455 ** If the number of virtual machine operations exceeds 2147483647
8456 ** then the value returned by this statement status code is undefined.
8458 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8459 ** <dd>^This is the number of times that the prepare statement has been
8460 ** automatically regenerated due to schema changes or changes to
8461 ** [bound parameters] that might affect the query plan.
8463 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8464 ** <dd>^This is the number of times that the prepared statement has
8465 ** been run. A single "run" for the purposes of this counter is one
8466 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8467 ** The counter is incremented on the first [sqlite3_step()] call of each
8470 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8471 ** <dd>^This is the approximate number of bytes of heap memory
8472 ** used to store the prepared statement. ^This value is not actually
8473 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8474 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8478 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8479 #define SQLITE_STMTSTATUS_SORT 2
8480 #define SQLITE_STMTSTATUS_AUTOINDEX 3
8481 #define SQLITE_STMTSTATUS_VM_STEP 4
8482 #define SQLITE_STMTSTATUS_REPREPARE 5
8483 #define SQLITE_STMTSTATUS_RUN 6
8484 #define SQLITE_STMTSTATUS_MEMUSED 99
8487 ** CAPI3REF: Custom Page Cache Object
8489 ** The sqlite3_pcache type is opaque. It is implemented by
8490 ** the pluggable module. The SQLite core has no knowledge of
8491 ** its size or internal structure and never deals with the
8492 ** sqlite3_pcache object except by holding and passing pointers
8495 ** See [sqlite3_pcache_methods2] for additional information.
8497 typedef struct sqlite3_pcache sqlite3_pcache;
8500 ** CAPI3REF: Custom Page Cache Object
8502 ** The sqlite3_pcache_page object represents a single page in the
8503 ** page cache. The page cache will allocate instances of this
8504 ** object. Various methods of the page cache use pointers to instances
8505 ** of this object as parameters or as their return value.
8507 ** See [sqlite3_pcache_methods2] for additional information.
8509 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8510 struct sqlite3_pcache_page {
8511 void *pBuf; /* The content of the page */
8512 void *pExtra; /* Extra information associated with the page */
8516 ** CAPI3REF: Application Defined Page Cache.
8517 ** KEYWORDS: {page cache}
8519 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8520 ** register an alternative page cache implementation by passing in an
8521 ** instance of the sqlite3_pcache_methods2 structure.)^
8522 ** In many applications, most of the heap memory allocated by
8523 ** SQLite is used for the page cache.
8524 ** By implementing a
8525 ** custom page cache using this API, an application can better control
8526 ** the amount of memory consumed by SQLite, the way in which
8527 ** that memory is allocated and released, and the policies used to
8528 ** determine exactly which parts of a database file are cached and for
8531 ** The alternative page cache mechanism is an
8532 ** extreme measure that is only needed by the most demanding applications.
8533 ** The built-in page cache is recommended for most uses.
8535 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8536 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8537 ** the application may discard the parameter after the call to
8538 ** [sqlite3_config()] returns.)^
8540 ** [[the xInit() page cache method]]
8541 ** ^(The xInit() method is called once for each effective
8542 ** call to [sqlite3_initialize()])^
8543 ** (usually only once during the lifetime of the process). ^(The xInit()
8544 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8545 ** The intent of the xInit() method is to set up global data structures
8546 ** required by the custom page cache implementation.
8547 ** ^(If the xInit() method is NULL, then the
8548 ** built-in default page cache is used instead of the application defined
8551 ** [[the xShutdown() page cache method]]
8552 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
8553 ** It can be used to clean up
8554 ** any outstanding resources before process shutdown, if required.
8555 ** ^The xShutdown() method may be NULL.
8557 ** ^SQLite automatically serializes calls to the xInit method,
8558 ** so the xInit method need not be threadsafe. ^The
8559 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
8560 ** not need to be threadsafe either. All other methods must be threadsafe
8561 ** in multithreaded applications.
8563 ** ^SQLite will never invoke xInit() more than once without an intervening
8564 ** call to xShutdown().
8566 ** [[the xCreate() page cache methods]]
8567 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
8568 ** SQLite will typically create one cache instance for each open database file,
8569 ** though this is not guaranteed. ^The
8570 ** first parameter, szPage, is the size in bytes of the pages that must
8571 ** be allocated by the cache. ^szPage will always a power of two. ^The
8572 ** second parameter szExtra is a number of bytes of extra storage
8573 ** associated with each page cache entry. ^The szExtra parameter will
8574 ** a number less than 250. SQLite will use the
8575 ** extra szExtra bytes on each page to store metadata about the underlying
8576 ** database page on disk. The value passed into szExtra depends
8577 ** on the SQLite version, the target platform, and how SQLite was compiled.
8578 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8579 ** created will be used to cache database pages of a file stored on disk, or
8580 ** false if it is used for an in-memory database. The cache implementation
8581 ** does not have to do anything special based with the value of bPurgeable;
8582 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8583 ** never invoke xUnpin() except to deliberately delete a page.
8584 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8585 ** false will always have the "discard" flag set to true.
8586 ** ^Hence, a cache created with bPurgeable false will
8587 ** never contain any unpinned pages.
8589 ** [[the xCachesize() page cache method]]
8590 ** ^(The xCachesize() method may be called at any time by SQLite to set the
8591 ** suggested maximum cache-size (number of pages stored by) the cache
8592 ** instance passed as the first argument. This is the value configured using
8593 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8594 ** parameter, the implementation is not required to do anything with this
8595 ** value; it is advisory only.
8597 ** [[the xPagecount() page cache methods]]
8598 ** The xPagecount() method must return the number of pages currently
8599 ** stored in the cache, both pinned and unpinned.
8601 ** [[the xFetch() page cache methods]]
8602 ** The xFetch() method locates a page in the cache and returns a pointer to
8603 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8604 ** The pBuf element of the returned sqlite3_pcache_page object will be a
8605 ** pointer to a buffer of szPage bytes used to store the content of a
8606 ** single database page. The pExtra element of sqlite3_pcache_page will be
8607 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
8608 ** for each entry in the page cache.
8610 ** The page to be fetched is determined by the key. ^The minimum key value
8611 ** is 1. After it has been retrieved using xFetch, the page is considered
8614 ** If the requested page is already in the page cache, then the page cache
8615 ** implementation must return a pointer to the page buffer with its content
8616 ** intact. If the requested page is not already in the cache, then the
8617 ** cache implementation should use the value of the createFlag
8618 ** parameter to help it determined what action to take:
8620 ** <table border=1 width=85% align=center>
8621 ** <tr><th> createFlag <th> Behavior when page is not already in cache
8622 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8623 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8624 ** Otherwise return NULL.
8625 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8626 ** NULL if allocating a new page is effectively impossible.
8629 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8630 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
8631 ** failed.)^ In between the xFetch() calls, SQLite may
8632 ** attempt to unpin one or more cache pages by spilling the content of
8633 ** pinned pages to disk and synching the operating system disk cache.
8635 ** [[the xUnpin() page cache method]]
8636 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8637 ** as its second argument. If the third parameter, discard, is non-zero,
8638 ** then the page must be evicted from the cache.
8639 ** ^If the discard parameter is
8640 ** zero, then the page may be discarded or retained at the discretion of
8641 ** page cache implementation. ^The page cache implementation
8642 ** may choose to evict unpinned pages at any time.
8644 ** The cache must not perform any reference counting. A single
8645 ** call to xUnpin() unpins the page regardless of the number of prior calls
8648 ** [[the xRekey() page cache methods]]
8649 ** The xRekey() method is used to change the key value associated with the
8650 ** page passed as the second argument. If the cache
8651 ** previously contains an entry associated with newKey, it must be
8652 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8655 ** When SQLite calls the xTruncate() method, the cache must discard all
8656 ** existing cache entries with page numbers (keys) greater than or equal
8657 ** to the value of the iLimit parameter passed to xTruncate(). If any
8658 ** of these pages are pinned, they are implicitly unpinned, meaning that
8659 ** they can be safely discarded.
8661 ** [[the xDestroy() page cache method]]
8662 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8663 ** All resources associated with the specified cache should be freed. ^After
8664 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8665 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8668 ** [[the xShrink() page cache method]]
8669 ** ^SQLite invokes the xShrink() method when it wants the page cache to
8670 ** free up as much of heap memory as possible. The page cache implementation
8671 ** is not obligated to free any memory, but well-behaved implementations should
8674 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8675 struct sqlite3_pcache_methods2 {
8678 int (*xInit)(void*);
8679 void (*xShutdown)(void*);
8680 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8681 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8682 int (*xPagecount)(sqlite3_pcache*);
8683 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8684 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8685 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8686 unsigned oldKey, unsigned newKey);
8687 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8688 void (*xDestroy)(sqlite3_pcache*);
8689 void (*xShrink)(sqlite3_pcache*);
8693 ** This is the obsolete pcache_methods object that has now been replaced
8694 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8695 ** retained in the header file for backwards compatibility only.
8697 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8698 struct sqlite3_pcache_methods {
8700 int (*xInit)(void*);
8701 void (*xShutdown)(void*);
8702 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8703 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8704 int (*xPagecount)(sqlite3_pcache*);
8705 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8706 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8707 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8708 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8709 void (*xDestroy)(sqlite3_pcache*);
8714 ** CAPI3REF: Online Backup Object
8716 ** The sqlite3_backup object records state information about an ongoing
8717 ** online backup operation. ^The sqlite3_backup object is created by
8718 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
8719 ** [sqlite3_backup_finish()].
8721 ** See Also: [Using the SQLite Online Backup API]
8723 typedef struct sqlite3_backup sqlite3_backup;
8726 ** CAPI3REF: Online Backup API.
8728 ** The backup API copies the content of one database into another.
8729 ** It is useful either for creating backups of databases or
8730 ** for copying in-memory databases to or from persistent files.
8732 ** See Also: [Using the SQLite Online Backup API]
8734 ** ^SQLite holds a write transaction open on the destination database file
8735 ** for the duration of the backup operation.
8736 ** ^The source database is read-locked only while it is being read;
8737 ** it is not locked continuously for the entire backup operation.
8738 ** ^Thus, the backup may be performed on a live source database without
8739 ** preventing other database connections from
8740 ** reading or writing to the source database while the backup is underway.
8742 ** ^(To perform a backup operation:
8744 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8746 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8747 ** the data between the two databases, and finally
8748 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8749 ** associated with the backup operation.
8751 ** There should be exactly one call to sqlite3_backup_finish() for each
8752 ** successful call to sqlite3_backup_init().
8754 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8756 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8757 ** [database connection] associated with the destination database
8758 ** and the database name, respectively.
8759 ** ^The database name is "main" for the main database, "temp" for the
8760 ** temporary database, or the name specified after the AS keyword in
8761 ** an [ATTACH] statement for an attached database.
8762 ** ^The S and M arguments passed to
8763 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8764 ** and database name of the source database, respectively.
8765 ** ^The source and destination [database connections] (parameters S and D)
8766 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8769 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8770 ** there is already a read or read-write transaction open on the
8771 ** destination database.
8773 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8774 ** returned and an error code and error message are stored in the
8775 ** destination [database connection] D.
8776 ** ^The error code and message for the failed call to sqlite3_backup_init()
8777 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8778 ** [sqlite3_errmsg16()] functions.
8779 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
8780 ** [sqlite3_backup] object.
8781 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8782 ** sqlite3_backup_finish() functions to perform the specified backup
8785 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8787 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8788 ** the source and destination databases specified by [sqlite3_backup] object B.
8789 ** ^If N is negative, all remaining source pages are copied.
8790 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8791 ** are still more pages to be copied, then the function returns [SQLITE_OK].
8792 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8793 ** from source to destination, then it returns [SQLITE_DONE].
8794 ** ^If an error occurs while running sqlite3_backup_step(B,N),
8795 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
8796 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8797 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8798 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8800 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8802 ** <li> the destination database was opened read-only, or
8803 ** <li> the destination database is using write-ahead-log journaling
8804 ** and the destination and source page sizes differ, or
8805 ** <li> the destination database is an in-memory database and the
8806 ** destination and source page sizes differ.
8809 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8810 ** the [sqlite3_busy_handler | busy-handler function]
8811 ** is invoked (if one is specified). ^If the
8812 ** busy-handler returns non-zero before the lock is available, then
8813 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8814 ** sqlite3_backup_step() can be retried later. ^If the source
8815 ** [database connection]
8816 ** is being used to write to the source database when sqlite3_backup_step()
8817 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8818 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
8819 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8820 ** [SQLITE_READONLY] is returned, then
8821 ** there is no point in retrying the call to sqlite3_backup_step(). These
8822 ** errors are considered fatal.)^ The application must accept
8823 ** that the backup operation has failed and pass the backup operation handle
8824 ** to the sqlite3_backup_finish() to release associated resources.
8826 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8827 ** on the destination file. ^The exclusive lock is not released until either
8828 ** sqlite3_backup_finish() is called or the backup operation is complete
8829 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8830 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
8831 ** lasts for the duration of the sqlite3_backup_step() call.
8832 ** ^Because the source database is not locked between calls to
8833 ** sqlite3_backup_step(), the source database may be modified mid-way
8834 ** through the backup process. ^If the source database is modified by an
8835 ** external process or via a database connection other than the one being
8836 ** used by the backup operation, then the backup will be automatically
8837 ** restarted by the next call to sqlite3_backup_step(). ^If the source
8838 ** database is modified by the using the same database connection as is used
8839 ** by the backup operation, then the backup database is automatically
8840 ** updated at the same time.
8842 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8844 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8845 ** application wishes to abandon the backup operation, the application
8846 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8847 ** ^The sqlite3_backup_finish() interfaces releases all
8848 ** resources associated with the [sqlite3_backup] object.
8849 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8850 ** active write-transaction on the destination database is rolled back.
8851 ** The [sqlite3_backup] object is invalid
8852 ** and may not be used following a call to sqlite3_backup_finish().
8854 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8855 ** sqlite3_backup_step() errors occurred, regardless or whether or not
8856 ** sqlite3_backup_step() completed.
8857 ** ^If an out-of-memory condition or IO error occurred during any prior
8858 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8859 ** sqlite3_backup_finish() returns the corresponding [error code].
8861 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8862 ** is not a permanent error and does not affect the return value of
8863 ** sqlite3_backup_finish().
8865 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8866 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8868 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
8869 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8870 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8871 ** in the source database at the conclusion of the most recent
8872 ** sqlite3_backup_step().
8873 ** ^(The values returned by these functions are only updated by
8874 ** sqlite3_backup_step(). If the source database is modified in a way that
8875 ** changes the size of the source database or the number of pages remaining,
8876 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
8877 ** and sqlite3_backup_remaining() until after the next
8878 ** sqlite3_backup_step().)^
8880 ** <b>Concurrent Usage of Database Handles</b>
8882 ** ^The source [database connection] may be used by the application for other
8883 ** purposes while a backup operation is underway or being initialized.
8884 ** ^If SQLite is compiled and configured to support threadsafe database
8885 ** connections, then the source database connection may be used concurrently
8886 ** from within other threads.
8888 ** However, the application must guarantee that the destination
8889 ** [database connection] is not passed to any other API (by any thread) after
8890 ** sqlite3_backup_init() is called and before the corresponding call to
8891 ** sqlite3_backup_finish(). SQLite does not currently check to see
8892 ** if the application incorrectly accesses the destination [database connection]
8893 ** and so no error code is reported, but the operations may malfunction
8894 ** nevertheless. Use of the destination database connection while a
8895 ** backup is in progress might also also cause a mutex deadlock.
8897 ** If running in [shared cache mode], the application must
8898 ** guarantee that the shared cache used by the destination database
8899 ** is not accessed while the backup is running. In practice this means
8900 ** that the application must guarantee that the disk file being
8901 ** backed up to is not accessed by any connection within the process,
8902 ** not just the specific connection that was passed to sqlite3_backup_init().
8904 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8905 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8906 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8907 ** APIs are not strictly speaking threadsafe. If they are invoked at the
8908 ** same time as another thread is invoking sqlite3_backup_step() it is
8909 ** possible that they return invalid values.
8911 SQLITE_API sqlite3_backup *sqlite3_backup_init(
8912 sqlite3 *pDest, /* Destination database handle */
8913 const char *zDestName, /* Destination database name */
8914 sqlite3 *pSource, /* Source database handle */
8915 const char *zSourceName /* Source database name */
8917 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8918 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8919 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8920 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8923 ** CAPI3REF: Unlock Notification
8926 ** ^When running in shared-cache mode, a database operation may fail with
8927 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8928 ** individual tables within the shared-cache cannot be obtained. See
8929 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8930 ** ^This API may be used to register a callback that SQLite will invoke
8931 ** when the connection currently holding the required lock relinquishes it.
8932 ** ^This API is only available if the library was compiled with the
8933 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8935 ** See Also: [Using the SQLite Unlock Notification Feature].
8937 ** ^Shared-cache locks are released when a database connection concludes
8938 ** its current transaction, either by committing it or rolling it back.
8940 ** ^When a connection (known as the blocked connection) fails to obtain a
8941 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8942 ** identity of the database connection (the blocking connection) that
8943 ** has locked the required resource is stored internally. ^After an
8944 ** application receives an SQLITE_LOCKED error, it may call the
8945 ** sqlite3_unlock_notify() method with the blocked connection handle as
8946 ** the first argument to register for a callback that will be invoked
8947 ** when the blocking connections current transaction is concluded. ^The
8948 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8949 ** call that concludes the blocking connection's transaction.
8951 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8952 ** there is a chance that the blocking connection will have already
8953 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8954 ** If this happens, then the specified callback is invoked immediately,
8955 ** from within the call to sqlite3_unlock_notify().)^
8957 ** ^If the blocked connection is attempting to obtain a write-lock on a
8958 ** shared-cache table, and more than one other connection currently holds
8959 ** a read-lock on the same table, then SQLite arbitrarily selects one of
8960 ** the other connections to use as the blocking connection.
8962 ** ^(There may be at most one unlock-notify callback registered by a
8963 ** blocked connection. If sqlite3_unlock_notify() is called when the
8964 ** blocked connection already has a registered unlock-notify callback,
8965 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8966 ** called with a NULL pointer as its second argument, then any existing
8967 ** unlock-notify callback is canceled. ^The blocked connections
8968 ** unlock-notify callback may also be canceled by closing the blocked
8969 ** connection using [sqlite3_close()].
8971 ** The unlock-notify callback is not reentrant. If an application invokes
8972 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
8973 ** crash or deadlock may be the result.
8975 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8976 ** returns SQLITE_OK.
8978 ** <b>Callback Invocation Details</b>
8980 ** When an unlock-notify callback is registered, the application provides a
8981 ** single void* pointer that is passed to the callback when it is invoked.
8982 ** However, the signature of the callback function allows SQLite to pass
8983 ** it an array of void* context pointers. The first argument passed to
8984 ** an unlock-notify callback is a pointer to an array of void* pointers,
8985 ** and the second is the number of entries in the array.
8987 ** When a blocking connection's transaction is concluded, there may be
8988 ** more than one blocked connection that has registered for an unlock-notify
8989 ** callback. ^If two or more such blocked connections have specified the
8990 ** same callback function, then instead of invoking the callback function
8991 ** multiple times, it is invoked once with the set of void* context pointers
8992 ** specified by the blocked connections bundled together into an array.
8993 ** This gives the application an opportunity to prioritize any actions
8994 ** related to the set of unblocked database connections.
8996 ** <b>Deadlock Detection</b>
8998 ** Assuming that after registering for an unlock-notify callback a
8999 ** database waits for the callback to be issued before taking any further
9000 ** action (a reasonable assumption), then using this API may cause the
9001 ** application to deadlock. For example, if connection X is waiting for
9002 ** connection Y's transaction to be concluded, and similarly connection
9003 ** Y is waiting on connection X's transaction, then neither connection
9004 ** will proceed and the system may remain deadlocked indefinitely.
9006 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9007 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9008 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9009 ** unlock-notify callback is registered. The system is said to be in
9010 ** a deadlocked state if connection A has registered for an unlock-notify
9011 ** callback on the conclusion of connection B's transaction, and connection
9012 ** B has itself registered for an unlock-notify callback when connection
9013 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9014 ** the system is also considered to be deadlocked if connection B has
9015 ** registered for an unlock-notify callback on the conclusion of connection
9016 ** C's transaction, where connection C is waiting on connection A. ^Any
9017 ** number of levels of indirection are allowed.
9019 ** <b>The "DROP TABLE" Exception</b>
9021 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9022 ** always appropriate to call sqlite3_unlock_notify(). There is however,
9023 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9024 ** SQLite checks if there are any currently executing SELECT statements
9025 ** that belong to the same connection. If there are, SQLITE_LOCKED is
9026 ** returned. In this case there is no "blocking connection", so invoking
9027 ** sqlite3_unlock_notify() results in the unlock-notify callback being
9028 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9029 ** or "DROP INDEX" query, an infinite loop might be the result.
9031 ** One way around this problem is to check the extended error code returned
9032 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9033 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9034 ** the special "DROP TABLE/INDEX" case, the extended error code is just
9037 SQLITE_API int sqlite3_unlock_notify(
9038 sqlite3 *pBlocked, /* Waiting connection */
9039 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9040 void *pNotifyArg /* Argument to pass to xNotify */
9045 ** CAPI3REF: String Comparison
9047 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9048 ** and extensions to compare the contents of two buffers containing UTF-8
9049 ** strings in a case-independent fashion, using the same definition of "case
9050 ** independence" that SQLite uses internally when comparing identifiers.
9052 SQLITE_API int sqlite3_stricmp(const char *, const char *);
9053 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9056 ** CAPI3REF: String Globbing
9058 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9059 ** string X matches the [GLOB] pattern P.
9060 ** ^The definition of [GLOB] pattern matching used in
9061 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9062 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9063 ** is case sensitive.
9065 ** Note that this routine returns zero on a match and non-zero if the strings
9066 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9068 ** See also: [sqlite3_strlike()].
9070 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9073 ** CAPI3REF: String LIKE Matching
9075 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9076 ** string X matches the [LIKE] pattern P with escape character E.
9077 ** ^The definition of [LIKE] pattern matching used in
9078 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9079 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9080 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9081 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9082 ** insensitive - equivalent upper and lower case ASCII characters match
9085 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9086 ** only ASCII characters are case folded.
9088 ** Note that this routine returns zero on a match and non-zero if the strings
9089 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9091 ** See also: [sqlite3_strglob()].
9093 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9096 ** CAPI3REF: Error Logging Interface
9098 ** ^The [sqlite3_log()] interface writes a message into the [error log]
9099 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9100 ** ^If logging is enabled, the zFormat string and subsequent arguments are
9101 ** used with [sqlite3_snprintf()] to generate the final output string.
9103 ** The sqlite3_log() interface is intended for use by extensions such as
9104 ** virtual tables, collating functions, and SQL functions. While there is
9105 ** nothing to prevent an application from calling sqlite3_log(), doing so
9106 ** is considered bad form.
9108 ** The zFormat string must not be NULL.
9110 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9111 ** will not use dynamically allocated memory. The log message is stored in
9112 ** a fixed-length buffer on the stack. If the log message is longer than
9113 ** a few hundred characters, it will be truncated to the length of the
9116 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9119 ** CAPI3REF: Write-Ahead Log Commit Hook
9122 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9123 ** is invoked each time data is committed to a database in wal mode.
9125 ** ^(The callback is invoked by SQLite after the commit has taken place and
9126 ** the associated write-lock on the database released)^, so the implementation
9127 ** may read, write or [checkpoint] the database as required.
9129 ** ^The first parameter passed to the callback function when it is invoked
9130 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9131 ** registering the callback. ^The second is a copy of the database handle.
9132 ** ^The third parameter is the name of the database that was written to -
9133 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9134 ** is the number of pages currently in the write-ahead log file,
9135 ** including those that were just committed.
9137 ** The callback function should normally return [SQLITE_OK]. ^If an error
9138 ** code is returned, that error will propagate back up through the
9139 ** SQLite code base to cause the statement that provoked the callback
9140 ** to report an error, though the commit will have still occurred. If the
9141 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9142 ** that does not correspond to any valid SQLite error code, the results
9145 ** A single database handle may have at most a single write-ahead log callback
9146 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9147 ** previously registered write-ahead log callback. ^The return value is
9148 ** a copy of the third parameter from the previous call, if any, or 0.
9149 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9150 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9151 ** overwrite any prior [sqlite3_wal_hook()] settings.
9153 SQLITE_API void *sqlite3_wal_hook(
9155 int(*)(void *,sqlite3*,const char*,int),
9160 ** CAPI3REF: Configure an auto-checkpoint
9163 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9164 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9165 ** to automatically [checkpoint]
9166 ** after committing a transaction if there are N or
9167 ** more frames in the [write-ahead log] file. ^Passing zero or
9168 ** a negative value as the nFrame parameter disables automatic
9169 ** checkpoints entirely.
9171 ** ^The callback registered by this function replaces any existing callback
9172 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9173 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9174 ** configured by this function.
9176 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9179 ** ^Checkpoints initiated by this mechanism are
9180 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9182 ** ^Every new [database connection] defaults to having the auto-checkpoint
9183 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9184 ** pages. The use of this interface
9185 ** is only necessary if the default setting is found to be suboptimal
9186 ** for a particular application.
9188 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9191 ** CAPI3REF: Checkpoint a database
9194 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9195 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9197 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9198 ** [write-ahead log] for database X on [database connection] D to be
9199 ** transferred into the database file and for the write-ahead log to
9200 ** be reset. See the [checkpointing] documentation for addition
9203 ** This interface used to be the only way to cause a checkpoint to
9204 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9205 ** interface was added. This interface is retained for backwards
9206 ** compatibility and as a convenience for applications that need to manually
9207 ** start a callback but which do not need the full power (and corresponding
9208 ** complication) of [sqlite3_wal_checkpoint_v2()].
9210 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9213 ** CAPI3REF: Checkpoint a database
9216 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9217 ** operation on database X of [database connection] D in mode M. Status
9218 ** information is written back into integers pointed to by L and C.)^
9219 ** ^(The M parameter must be a valid [checkpoint mode]:)^
9222 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9223 ** ^Checkpoint as many frames as possible without waiting for any database
9224 ** readers or writers to finish, then sync the database file if all frames
9225 ** in the log were checkpointed. ^The [busy-handler callback]
9226 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9227 ** ^On the other hand, passive mode might leave the checkpoint unfinished
9228 ** if there are concurrent readers or writers.
9230 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9231 ** ^This mode blocks (it invokes the
9232 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9233 ** database writer and all readers are reading from the most recent database
9234 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9235 ** database file. ^This mode blocks new database writers while it is pending,
9236 ** but new database readers are allowed to continue unimpeded.
9238 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9239 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9240 ** that after checkpointing the log file it blocks (calls the
9241 ** [busy-handler callback])
9242 ** until all readers are reading from the database file only. ^This ensures
9243 ** that the next writer will restart the log file from the beginning.
9244 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9245 ** database writer attempts while it is pending, but does not impede readers.
9247 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9248 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9249 ** addition that it also truncates the log file to zero bytes just prior
9250 ** to a successful return.
9253 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9254 ** the log file or to -1 if the checkpoint could not run because
9255 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9256 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9257 ** log file (including any that were already checkpointed before the function
9258 ** was called) or to -1 if the checkpoint could not run due to an error or
9259 ** because the database is not in WAL mode. ^Note that upon successful
9260 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9261 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9263 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9264 ** any other process is running a checkpoint operation at the same time, the
9265 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9266 ** busy-handler configured, it will not be invoked in this case.
9268 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9269 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9270 ** obtained immediately, and a busy-handler is configured, it is invoked and
9271 ** the writer lock retried until either the busy-handler returns 0 or the lock
9272 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9273 ** database readers as described above. ^If the busy-handler returns 0 before
9274 ** the writer lock is obtained or while waiting for database readers, the
9275 ** checkpoint operation proceeds from that point in the same way as
9276 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9277 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
9279 ** ^If parameter zDb is NULL or points to a zero length string, then the
9280 ** specified operation is attempted on all WAL databases [attached] to
9281 ** [database connection] db. In this case the
9282 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9283 ** an SQLITE_BUSY error is encountered when processing one or more of the
9284 ** attached WAL databases, the operation is still attempted on any remaining
9285 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9286 ** error occurs while processing an attached database, processing is abandoned
9287 ** and the error code is returned to the caller immediately. ^If no error
9288 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9289 ** databases, SQLITE_OK is returned.
9291 ** ^If database zDb is the name of an attached database that is not in WAL
9292 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9293 ** zDb is not NULL (or a zero length string) and is not the name of any
9294 ** attached database, SQLITE_ERROR is returned to the caller.
9296 ** ^Unless it returns SQLITE_MISUSE,
9297 ** the sqlite3_wal_checkpoint_v2() interface
9298 ** sets the error information that is queried by
9299 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9301 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9304 SQLITE_API int sqlite3_wal_checkpoint_v2(
9305 sqlite3 *db, /* Database handle */
9306 const char *zDb, /* Name of attached database (or NULL) */
9307 int eMode, /* SQLITE_CHECKPOINT_* value */
9308 int *pnLog, /* OUT: Size of WAL log in frames */
9309 int *pnCkpt /* OUT: Total number of frames checkpointed */
9313 ** CAPI3REF: Checkpoint Mode Values
9314 ** KEYWORDS: {checkpoint mode}
9316 ** These constants define all valid values for the "checkpoint mode" passed
9317 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9318 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9319 ** meaning of each of these checkpoint modes.
9321 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9322 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9323 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9324 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9327 ** CAPI3REF: Virtual Table Interface Configuration
9329 ** This function may be called by either the [xConnect] or [xCreate] method
9330 ** of a [virtual table] implementation to configure
9331 ** various facets of the virtual table interface.
9333 ** If this interface is invoked outside the context of an xConnect or
9334 ** xCreate virtual table method then the behavior is undefined.
9336 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9337 ** [database connection] in which the virtual table is being created and
9338 ** which is passed in as the first argument to the [xConnect] or [xCreate]
9339 ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9340 ** of the [virtual table configuration options]. The presence and meaning
9341 ** of parameters after C depend on which [virtual table configuration option]
9344 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9347 ** CAPI3REF: Virtual Table Configuration Options
9348 ** KEYWORDS: {virtual table configuration options}
9349 ** KEYWORDS: {virtual table configuration option}
9351 ** These macros define the various options to the
9352 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9353 ** can use to customize and optimize their behavior.
9356 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9357 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9358 ** <dd>Calls of the form
9359 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9360 ** where X is an integer. If X is zero, then the [virtual table] whose
9361 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9362 ** support constraints. In this configuration (which is the default) if
9363 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9364 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9365 ** specified as part of the users SQL statement, regardless of the actual
9366 ** ON CONFLICT mode specified.
9368 ** If X is non-zero, then the virtual table implementation guarantees
9369 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9370 ** any modifications to internal or persistent data structures have been made.
9371 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9372 ** is able to roll back a statement or database transaction, and abandon
9373 ** or continue processing the current SQL statement as appropriate.
9374 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9375 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9378 ** Virtual table implementations that are required to handle OR REPLACE
9379 ** must do so within the [xUpdate] method. If a call to the
9380 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9381 ** CONFLICT policy is REPLACE, the virtual table implementation should
9382 ** silently replace the appropriate rows within the xUpdate callback and
9383 ** return SQLITE_OK. Or, if this is not possible, it may return
9384 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9385 ** constraint handling.
9388 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9389 ** <dd>Calls of the form
9390 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9391 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9392 ** prohibits that virtual table from being used from within triggers and
9396 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9397 ** <dd>Calls of the form
9398 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9399 ** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9400 ** identify that virtual table as being safe to use from within triggers
9401 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9402 ** virtual table can do no serious harm even if it is controlled by a
9403 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9404 ** flag unless absolutely necessary.
9408 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9409 #define SQLITE_VTAB_INNOCUOUS 2
9410 #define SQLITE_VTAB_DIRECTONLY 3
9413 ** CAPI3REF: Determine The Virtual Table Conflict Policy
9415 ** This function may only be called from within a call to the [xUpdate] method
9416 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9417 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9418 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9419 ** of the SQL statement that triggered the call to the [xUpdate] method of the
9422 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9425 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9427 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9428 ** method of a [virtual table], then it might return true if the
9429 ** column is being fetched as part of an UPDATE operation during which the
9430 ** column value will not change. The virtual table implementation can use
9431 ** this hint as permission to substitute a return value that is less
9432 ** expensive to compute and that the corresponding
9433 ** [xUpdate] method understands as a "no-change" value.
9435 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9436 ** the column is not changed by the UPDATE statement, then the xColumn
9437 ** method can optionally return without setting a result, without calling
9438 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9439 ** In that case, [sqlite3_value_nochange(X)] will return true for the
9440 ** same column in the [xUpdate] method.
9442 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9443 ** implementations should continue to give a correct answer even if the
9444 ** sqlite3_vtab_nochange() interface were to always return false. In the
9445 ** current implementation, the sqlite3_vtab_nochange() interface does always
9446 ** returns false for the enhanced [UPDATE FROM] statement.
9448 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9451 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9453 ** This function may only be called from within a call to the [xBestIndex]
9454 ** method of a [virtual table].
9456 ** The first argument must be the sqlite3_index_info object that is the
9457 ** first parameter to the xBestIndex() method. The second argument must be
9458 ** an index into the aConstraint[] array belonging to the sqlite3_index_info
9459 ** structure passed to xBestIndex. This function returns a pointer to a buffer
9460 ** containing the name of the collation sequence for the corresponding
9463 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9466 ** CAPI3REF: Conflict resolution modes
9467 ** KEYWORDS: {conflict resolution mode}
9469 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
9470 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
9471 ** is for the SQL statement being evaluated.
9473 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
9474 ** return value from the [sqlite3_set_authorizer()] callback and that
9475 ** [SQLITE_ABORT] is also a [result code].
9477 #define SQLITE_ROLLBACK 1
9478 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9479 #define SQLITE_FAIL 3
9480 /* #define SQLITE_ABORT 4 // Also an error code */
9481 #define SQLITE_REPLACE 5
9484 ** CAPI3REF: Prepared Statement Scan Status Opcodes
9485 ** KEYWORDS: {scanstatus options}
9487 ** The following constants can be used for the T parameter to the
9488 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9489 ** different metric for sqlite3_stmt_scanstatus() to return.
9491 ** When the value returned to V is a string, space to hold that string is
9492 ** managed by the prepared statement S and will be automatically freed when
9496 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9497 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9498 ** set to the total number of times that the X-th loop has run.</dd>
9500 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9501 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9502 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
9504 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9505 ** <dd>^The "double" variable pointed to by the V parameter will be set to the
9506 ** query planner's estimate for the average number of rows output from each
9507 ** iteration of the X-th loop. If the query planner's estimates was accurate,
9508 ** then this value will approximate the quotient NVISIT/NLOOP and the
9509 ** product of this value for all prior loops with the same SELECTID will
9510 ** be the NLOOP value for the current loop.
9512 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9513 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
9514 ** to a zero-terminated UTF-8 string containing the name of the index or table
9515 ** used for the X-th loop.
9517 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9518 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
9519 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9520 ** description for the X-th loop.
9522 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9523 ** <dd>^The "int" variable pointed to by the V parameter will be set to the
9524 ** "select-id" for the X-th loop. The select-id identifies which query or
9525 ** subquery the loop is part of. The main query has a select-id of zero.
9526 ** The select-id is the same value as is output in the first column
9527 ** of an [EXPLAIN QUERY PLAN] query.
9530 #define SQLITE_SCANSTAT_NLOOP 0
9531 #define SQLITE_SCANSTAT_NVISIT 1
9532 #define SQLITE_SCANSTAT_EST 2
9533 #define SQLITE_SCANSTAT_NAME 3
9534 #define SQLITE_SCANSTAT_EXPLAIN 4
9535 #define SQLITE_SCANSTAT_SELECTID 5
9538 ** CAPI3REF: Prepared Statement Scan Status
9539 ** METHOD: sqlite3_stmt
9541 ** This interface returns information about the predicted and measured
9542 ** performance for pStmt. Advanced applications can use this
9543 ** interface to compare the predicted and the measured performance and
9544 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9546 ** Since this interface is expected to be rarely used, it is only
9547 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9548 ** compile-time option.
9550 ** The "iScanStatusOp" parameter determines which status information to return.
9551 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9552 ** of this interface is undefined.
9553 ** ^The requested measurement is written into a variable pointed to by
9554 ** the "pOut" parameter.
9555 ** Parameter "idx" identifies the specific loop to retrieve statistics for.
9556 ** Loops are numbered starting from zero. ^If idx is out of range - less than
9557 ** zero or greater than or equal to the total number of loops used to implement
9558 ** the statement - a non-zero value is returned and the variable that pOut
9559 ** points to is unchanged.
9561 ** ^Statistics might not be available for all loops in all statements. ^In cases
9562 ** where there exist loops with no available statistics, this function behaves
9563 ** as if the loop did not exist - it returns non-zero and leave the variable
9564 ** that pOut points to unchanged.
9566 ** See also: [sqlite3_stmt_scanstatus_reset()]
9568 SQLITE_API int sqlite3_stmt_scanstatus(
9569 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9570 int idx, /* Index of loop to report on */
9571 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9572 void *pOut /* Result written here */
9576 ** CAPI3REF: Zero Scan-Status Counters
9577 ** METHOD: sqlite3_stmt
9579 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9581 ** This API is only available if the library is built with pre-processor
9582 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9584 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9587 ** CAPI3REF: Flush caches to disk mid-transaction
9590 ** ^If a write-transaction is open on [database connection] D when the
9591 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9592 ** pages in the pager-cache that are not currently in use are written out
9593 ** to disk. A dirty page may be in use if a database cursor created by an
9594 ** active SQL statement is reading from it, or if it is page 1 of a database
9595 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9596 ** interface flushes caches for all schemas - "main", "temp", and
9597 ** any [attached] databases.
9599 ** ^If this function needs to obtain extra database locks before dirty pages
9600 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
9601 ** immediately and there is a busy-handler callback configured, it is invoked
9602 ** in the usual manner. ^If the required lock still cannot be obtained, then
9603 ** the database is skipped and an attempt made to flush any dirty pages
9604 ** belonging to the next (if any) database. ^If any databases are skipped
9605 ** because locks cannot be obtained, but no other error occurs, this
9606 ** function returns SQLITE_BUSY.
9608 ** ^If any other error occurs while flushing dirty pages to disk (for
9609 ** example an IO error or out-of-memory condition), then processing is
9610 ** abandoned and an SQLite [error code] is returned to the caller immediately.
9612 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9614 ** ^This function does not set the database handle error code or message
9615 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9617 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9620 ** CAPI3REF: The pre-update hook.
9623 ** ^These interfaces are only available if SQLite is compiled using the
9624 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9626 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9627 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
9628 ** on a database table.
9629 ** ^At most one preupdate hook may be registered at a time on a single
9630 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9631 ** the previous setting.
9632 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9633 ** with a NULL pointer as the second parameter.
9634 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9635 ** the first parameter to callbacks.
9637 ** ^The preupdate hook only fires for changes to real database tables; the
9638 ** preupdate hook is not invoked for changes to [virtual tables] or to
9639 ** system tables like sqlite_sequence or sqlite_stat1.
9641 ** ^The second parameter to the preupdate callback is a pointer to
9642 ** the [database connection] that registered the preupdate hook.
9643 ** ^The third parameter to the preupdate callback is one of the constants
9644 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9645 ** kind of update operation that is about to occur.
9646 ** ^(The fourth parameter to the preupdate callback is the name of the
9647 ** database within the database connection that is being modified. This
9648 ** will be "main" for the main database or "temp" for TEMP tables or
9649 ** the name given after the AS keyword in the [ATTACH] statement for attached
9651 ** ^The fifth parameter to the preupdate callback is the name of the
9652 ** table that is being modified.
9654 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
9655 ** parameter passed to the preupdate callback is the initial [rowid] of the
9656 ** row being modified or deleted. For an INSERT operation on a rowid table,
9657 ** or any operation on a WITHOUT ROWID table, the value of the sixth
9658 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
9659 ** seventh parameter is the final rowid value of the row being inserted
9660 ** or updated. The value of the seventh parameter passed to the callback
9661 ** function is not defined for operations on WITHOUT ROWID tables, or for
9662 ** DELETE operations on rowid tables.
9664 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9665 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9666 ** provide additional information about a preupdate event. These routines
9667 ** may only be called from within a preupdate callback. Invoking any of
9668 ** these routines from outside of a preupdate callback or with a
9669 ** [database connection] pointer that is different from the one supplied
9670 ** to the preupdate callback results in undefined and probably undesirable
9673 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9674 ** in the row that is being inserted, updated, or deleted.
9676 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9677 ** a [protected sqlite3_value] that contains the value of the Nth column of
9678 ** the table row before it is updated. The N parameter must be between 0
9679 ** and one less than the number of columns or the behavior will be
9680 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9681 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9682 ** behavior is undefined. The [sqlite3_value] that P points to
9683 ** will be destroyed when the preupdate callback returns.
9685 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9686 ** a [protected sqlite3_value] that contains the value of the Nth column of
9687 ** the table row after it is updated. The N parameter must be between 0
9688 ** and one less than the number of columns or the behavior will be
9689 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9690 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9691 ** behavior is undefined. The [sqlite3_value] that P points to
9692 ** will be destroyed when the preupdate callback returns.
9694 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9695 ** callback was invoked as a result of a direct insert, update, or delete
9696 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
9697 ** triggers; or 2 for changes resulting from triggers called by top-level
9698 ** triggers; and so forth.
9700 ** When the [sqlite3_blob_write()] API is used to update a blob column,
9701 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the
9702 ** in this case the new values are not available. In this case, when a
9703 ** callback made with op==SQLITE_DELETE is actuall a write using the
9704 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
9705 ** the index of the column being written. In other cases, where the
9706 ** pre-update hook is being invoked for some other reason, including a
9707 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
9709 ** See also: [sqlite3_update_hook()]
9711 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9712 SQLITE_API void *sqlite3_preupdate_hook(
9715 void *pCtx, /* Copy of third arg to preupdate_hook() */
9716 sqlite3 *db, /* Database handle */
9717 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9718 char const *zDb, /* Database name */
9719 char const *zName, /* Table name */
9720 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9721 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9725 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9726 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9727 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9728 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9729 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
9733 ** CAPI3REF: Low-level system error code
9736 ** ^Attempt to return the underlying operating system error code or error
9737 ** number that caused the most recent I/O error or failure to open a file.
9738 ** The return value is OS-dependent. For example, on unix systems, after
9739 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9740 ** called to get back the underlying "errno" that caused the problem, such
9741 ** as ENOSPC, EAUTH, EISDIR, and so forth.
9743 SQLITE_API int sqlite3_system_errno(sqlite3*);
9746 ** CAPI3REF: Database Snapshot
9747 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
9749 ** An instance of the snapshot object records the state of a [WAL mode]
9750 ** database for some specific point in history.
9752 ** In [WAL mode], multiple [database connections] that are open on the
9753 ** same database file can each be reading a different historical version
9754 ** of the database file. When a [database connection] begins a read
9755 ** transaction, that connection sees an unchanging copy of the database
9756 ** as it existed for the point in time when the transaction first started.
9757 ** Subsequent changes to the database from other connections are not seen
9758 ** by the reader until a new read transaction is started.
9760 ** The sqlite3_snapshot object records state information about an historical
9761 ** version of the database file so that it is possible to later open a new read
9762 ** transaction that sees that historical version of the database rather than
9763 ** the most recent version.
9765 typedef struct sqlite3_snapshot {
9766 unsigned char hidden[48];
9770 ** CAPI3REF: Record A Database Snapshot
9771 ** CONSTRUCTOR: sqlite3_snapshot
9773 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9774 ** new [sqlite3_snapshot] object that records the current state of
9775 ** schema S in database connection D. ^On success, the
9776 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9777 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9778 ** If there is not already a read-transaction open on schema S when
9779 ** this function is called, one is opened automatically.
9781 ** The following must be true for this function to succeed. If any of
9782 ** the following statements are false when sqlite3_snapshot_get() is
9783 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
9787 ** <li> The database handle must not be in [autocommit mode].
9789 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
9791 ** <li> There must not be a write transaction open on schema S of database
9794 ** <li> One or more transactions must have been written to the current wal
9795 ** file since it was created on disk (by any connection). This means
9796 ** that a snapshot cannot be taken on a wal mode database with no wal
9797 ** file immediately after it is first opened. At least one transaction
9798 ** must be written to it first.
9801 ** This function may also return SQLITE_NOMEM. If it is called with the
9802 ** database handle in autocommit mode but fails for some other reason,
9803 ** whether or not a read transaction is opened on schema S is undefined.
9805 ** The [sqlite3_snapshot] object returned from a successful call to
9806 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9807 ** to avoid a memory leak.
9809 ** The [sqlite3_snapshot_get()] interface is only available when the
9810 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9812 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9814 const char *zSchema,
9815 sqlite3_snapshot **ppSnapshot
9819 ** CAPI3REF: Start a read transaction on an historical snapshot
9820 ** METHOD: sqlite3_snapshot
9822 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9823 ** transaction or upgrades an existing one for schema S of
9824 ** [database connection] D such that the read transaction refers to
9825 ** historical [snapshot] P, rather than the most recent change to the
9826 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9827 ** on success or an appropriate [error code] if it fails.
9829 ** ^In order to succeed, the database connection must not be in
9830 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9831 ** is already a read transaction open on schema S, then the database handle
9832 ** must have no active statements (SELECT statements that have been passed
9833 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9834 ** SQLITE_ERROR is returned if either of these conditions is violated, or
9835 ** if schema S does not exist, or if the snapshot object is invalid.
9837 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9838 ** snapshot has been overwritten by a [checkpoint]. In this case
9839 ** SQLITE_ERROR_SNAPSHOT is returned.
9841 ** If there is already a read transaction open when this function is
9842 ** invoked, then the same read transaction remains open (on the same
9843 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9844 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
9845 ** SQLITE_IOERR error code - is returned, then the final state of the
9846 ** read transaction is undefined. If SQLITE_OK is returned, then the
9847 ** read transaction is now open on database snapshot P.
9849 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9850 ** database connection D does not know that the database file for
9851 ** schema S is in [WAL mode]. A database connection might not know
9852 ** that the database file is in [WAL mode] if there has been no prior
9853 ** I/O on that database connection, or if the database entered [WAL mode]
9854 ** after the most recent I/O on the database connection.)^
9855 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
9856 ** database connection in order to make it ready to use snapshots.)
9858 ** The [sqlite3_snapshot_open()] interface is only available when the
9859 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9861 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9863 const char *zSchema,
9864 sqlite3_snapshot *pSnapshot
9868 ** CAPI3REF: Destroy a snapshot
9869 ** DESTRUCTOR: sqlite3_snapshot
9871 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9872 ** The application must eventually free every [sqlite3_snapshot] object
9873 ** using this routine to avoid a memory leak.
9875 ** The [sqlite3_snapshot_free()] interface is only available when the
9876 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9878 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9881 ** CAPI3REF: Compare the ages of two snapshot handles.
9882 ** METHOD: sqlite3_snapshot
9884 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9885 ** of two valid snapshot handles.
9887 ** If the two snapshot handles are not associated with the same database
9888 ** file, the result of the comparison is undefined.
9890 ** Additionally, the result of the comparison is only valid if both of the
9891 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9892 ** last time the wal file was deleted. The wal file is deleted when the
9893 ** database is changed back to rollback mode or when the number of database
9894 ** clients drops to zero. If either snapshot handle was obtained before the
9895 ** wal file was last deleted, the value returned by this function
9898 ** Otherwise, this API returns a negative value if P1 refers to an older
9899 ** snapshot than P2, zero if the two handles refer to the same database
9900 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
9902 ** This interface is only available if SQLite is compiled with the
9903 ** [SQLITE_ENABLE_SNAPSHOT] option.
9905 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9906 sqlite3_snapshot *p1,
9907 sqlite3_snapshot *p2
9911 ** CAPI3REF: Recover snapshots from a wal file
9912 ** METHOD: sqlite3_snapshot
9914 ** If a [WAL file] remains on disk after all database connections close
9915 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9916 ** or because the last process to have the database opened exited without
9917 ** calling [sqlite3_close()]) and a new connection is subsequently opened
9918 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9919 ** will only be able to open the last transaction added to the WAL file
9920 ** even though the WAL file contains other valid transactions.
9922 ** This function attempts to scan the WAL file associated with database zDb
9923 ** of database handle db and make all valid snapshots available to
9924 ** sqlite3_snapshot_open(). It is an error if there is already a read
9925 ** transaction open on the database, or if the database is not a WAL mode
9928 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9930 ** This interface is only available if SQLite is compiled with the
9931 ** [SQLITE_ENABLE_SNAPSHOT] option.
9933 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9936 ** CAPI3REF: Serialize a database
9938 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9939 ** that is a serialization of the S database on [database connection] D.
9940 ** If P is not a NULL pointer, then the size of the database in bytes
9941 ** is written into *P.
9943 ** For an ordinary on-disk database file, the serialization is just a
9944 ** copy of the disk file. For an in-memory database or a "TEMP" database,
9945 ** the serialization is the same sequence of bytes which would be written
9946 ** to disk if that database where backed up to disk.
9948 ** The usual case is that sqlite3_serialize() copies the serialization of
9949 ** the database into memory obtained from [sqlite3_malloc64()] and returns
9950 ** a pointer to that memory. The caller is responsible for freeing the
9951 ** returned value to avoid a memory leak. However, if the F argument
9952 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9953 ** are made, and the sqlite3_serialize() function will return a pointer
9954 ** to the contiguous memory representation of the database that SQLite
9955 ** is currently using for that database, or NULL if the no such contiguous
9956 ** memory representation of the database exists. A contiguous memory
9957 ** representation of the database will usually only exist if there has
9958 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9959 ** values of D and S.
9960 ** The size of the database is written into *P even if the
9961 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9962 ** of the database exists.
9964 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9965 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9966 ** allocation error occurs.
9968 ** This interface is omitted if SQLite is compiled with the
9969 ** [SQLITE_OMIT_DESERIALIZE] option.
9971 SQLITE_API unsigned char *sqlite3_serialize(
9972 sqlite3 *db, /* The database connection */
9973 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9974 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9975 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9979 ** CAPI3REF: Flags for sqlite3_serialize
9981 ** Zero or more of the following constants can be OR-ed together for
9982 ** the F argument to [sqlite3_serialize(D,S,P,F)].
9984 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9985 ** a pointer to contiguous in-memory database that it is currently using,
9986 ** without making a copy of the database. If SQLite is not currently using
9987 ** a contiguous in-memory database, then this option causes
9988 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9989 ** using a contiguous in-memory database if it has been initialized by a
9990 ** prior call to [sqlite3_deserialize()].
9992 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9995 ** CAPI3REF: Deserialize a database
9997 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9998 ** [database connection] D to disconnect from database S and then
9999 ** reopen S as an in-memory database based on the serialization contained
10000 ** in P. The serialized database P is N bytes in size. M is the size of
10001 ** the buffer P, which might be larger than N. If M is larger than N, and
10002 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10003 ** permitted to add content to the in-memory database as long as the total
10004 ** size does not exceed M bytes.
10006 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10007 ** invoke sqlite3_free() on the serialization buffer when the database
10008 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10009 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
10010 ** if writes on the database cause it to grow larger than M bytes.
10012 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10013 ** database is currently in a read transaction or is involved in a backup
10016 ** It is not possible to deserialized into the TEMP database. If the
10017 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10018 ** function returns SQLITE_ERROR.
10020 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10021 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10022 ** [sqlite3_free()] is invoked on argument P prior to returning.
10024 ** This interface is omitted if SQLite is compiled with the
10025 ** [SQLITE_OMIT_DESERIALIZE] option.
10027 SQLITE_API int sqlite3_deserialize(
10028 sqlite3 *db, /* The database connection */
10029 const char *zSchema, /* Which DB to reopen with the deserialization */
10030 unsigned char *pData, /* The serialized database content */
10031 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10032 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10033 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10037 ** CAPI3REF: Flags for sqlite3_deserialize()
10039 ** The following are allowed values for 6th argument (the F argument) to
10040 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10042 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10043 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10044 ** and that SQLite should take ownership of this memory and automatically
10045 ** free it when it has finished using it. Without this flag, the caller
10046 ** is responsible for freeing any dynamically allocated memory.
10048 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10049 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
10050 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10051 ** Without this flag, the deserialized database cannot increase in size beyond
10052 ** the number of bytes specified by the M parameter.
10054 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10055 ** should be treated as read-only.
10057 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10058 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10059 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10062 ** Undo the hack that converts floating point types to integer for
10063 ** builds on processors without floating point support.
10065 #ifdef SQLITE_OMIT_FLOATING_POINT
10070 } /* End of the 'extern "C"' block */
10072 #endif /* SQLITE3_H */
10074 /******** Begin file sqlite3rtree.h *********/
10078 ** The author disclaims copyright to this source code. In place of
10079 ** a legal notice, here is a blessing:
10081 ** May you do good and not evil.
10082 ** May you find forgiveness for yourself and forgive others.
10083 ** May you share freely, never taking more than you give.
10085 *************************************************************************
10088 #ifndef _SQLITE3RTREE_H_
10089 #define _SQLITE3RTREE_H_
10096 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10097 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10099 /* The double-precision datatype used by RTree depends on the
10100 ** SQLITE_RTREE_INT_ONLY compile-time option.
10102 #ifdef SQLITE_RTREE_INT_ONLY
10103 typedef sqlite3_int64 sqlite3_rtree_dbl;
10105 typedef double sqlite3_rtree_dbl;
10109 ** Register a geometry callback named zGeom that can be used as part of an
10110 ** R-Tree geometry query as follows:
10112 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10114 SQLITE_API int sqlite3_rtree_geometry_callback(
10117 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10123 ** A pointer to a structure of the following type is passed as the first
10124 ** argument to callbacks registered using rtree_geometry_callback().
10126 struct sqlite3_rtree_geometry {
10127 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10128 int nParam; /* Size of array aParam[] */
10129 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10130 void *pUser; /* Callback implementation user data */
10131 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10135 ** Register a 2nd-generation geometry callback named zScore that can be
10136 ** used as part of an R-Tree geometry query as follows:
10138 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10140 SQLITE_API int sqlite3_rtree_query_callback(
10142 const char *zQueryFunc,
10143 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10145 void (*xDestructor)(void*)
10150 ** A pointer to a structure of the following type is passed as the
10151 ** argument to scored geometry callback registered using
10152 ** sqlite3_rtree_query_callback().
10154 ** Note that the first 5 fields of this structure are identical to
10155 ** sqlite3_rtree_geometry. This structure is a subclass of
10156 ** sqlite3_rtree_geometry.
10158 struct sqlite3_rtree_query_info {
10159 void *pContext; /* pContext from when function registered */
10160 int nParam; /* Number of function parameters */
10161 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10162 void *pUser; /* callback can use this, if desired */
10163 void (*xDelUser)(void*); /* function to free pUser */
10164 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10165 unsigned int *anQueue; /* Number of pending entries in the queue */
10166 int nCoord; /* Number of coordinates */
10167 int iLevel; /* Level of current node or entry */
10168 int mxLevel; /* The largest iLevel value in the tree */
10169 sqlite3_int64 iRowid; /* Rowid for current entry */
10170 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10171 int eParentWithin; /* Visibility of parent node */
10172 int eWithin; /* OUT: Visibility */
10173 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10174 /* The following fields are only available in 3.8.11 and later */
10175 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10179 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10181 #define NOT_WITHIN 0 /* Object completely outside of query region */
10182 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10183 #define FULLY_WITHIN 2 /* Object fully contained within query region */
10187 } /* end of the 'extern "C"' block */
10190 #endif /* ifndef _SQLITE3RTREE_H_ */
10192 /******** End of sqlite3rtree.h *********/
10193 /******** Begin file sqlite3session.h *********/
10195 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10196 #define __SQLITESESSION_H_ 1
10199 ** Make sure we can call this stuff from C++.
10207 ** CAPI3REF: Session Object Handle
10209 ** An instance of this object is a [session] that can be used to
10210 ** record changes to a database.
10212 typedef struct sqlite3_session sqlite3_session;
10215 ** CAPI3REF: Changeset Iterator Handle
10217 ** An instance of this object acts as a cursor for iterating
10218 ** over the elements of a [changeset] or [patchset].
10220 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10223 ** CAPI3REF: Create A New Session Object
10224 ** CONSTRUCTOR: sqlite3_session
10226 ** Create a new session object attached to database handle db. If successful,
10227 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
10228 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10229 ** error code (e.g. SQLITE_NOMEM) is returned.
10231 ** It is possible to create multiple session objects attached to a single
10232 ** database handle.
10234 ** Session objects created using this function should be deleted using the
10235 ** [sqlite3session_delete()] function before the database handle that they
10236 ** are attached to is itself closed. If the database handle is closed before
10237 ** the session object is deleted, then the results of calling any session
10238 ** module function, including [sqlite3session_delete()] on the session object
10241 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10242 ** is not possible for an application to register a pre-update hook on a
10243 ** database handle that has one or more session objects attached. Nor is
10244 ** it possible to create a session object attached to a database handle for
10245 ** which a pre-update hook is already defined. The results of attempting
10246 ** either of these things are undefined.
10248 ** The session object will be used to create changesets for tables in
10249 ** database zDb, where zDb is either "main", or "temp", or the name of an
10250 ** attached database. It is not an error if database zDb is not attached
10251 ** to the database when the session object is created.
10253 SQLITE_API int sqlite3session_create(
10254 sqlite3 *db, /* Database handle */
10255 const char *zDb, /* Name of db (e.g. "main") */
10256 sqlite3_session **ppSession /* OUT: New session object */
10260 ** CAPI3REF: Delete A Session Object
10261 ** DESTRUCTOR: sqlite3_session
10263 ** Delete a session object previously allocated using
10264 ** [sqlite3session_create()]. Once a session object has been deleted, the
10265 ** results of attempting to use pSession with any other session module
10266 ** function are undefined.
10268 ** Session objects must be deleted before the database handle to which they
10269 ** are attached is closed. Refer to the documentation for
10270 ** [sqlite3session_create()] for details.
10272 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10275 ** CAPIREF: Conigure a Session Object
10276 ** METHOD: sqlite3_session
10278 ** This method is used to configure a session object after it has been
10279 ** created. At present the only valid value for the second parameter is
10280 ** [SQLITE_SESSION_OBJCONFIG_SIZE].
10282 ** Arguments for sqlite3session_object_config()
10284 ** The following values may passed as the the 4th parameter to
10285 ** sqlite3session_object_config().
10287 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10288 ** This option is used to set, clear or query the flag that enables
10289 ** the [sqlite3session_changeset_size()] API. Because it imposes some
10290 ** computational overhead, this API is disabled by default. Argument
10291 ** pArg must point to a value of type (int). If the value is initially
10292 ** 0, then the sqlite3session_changeset_size() API is disabled. If it
10293 ** is greater than 0, then the same API is enabled. Or, if the initial
10294 ** value is less than zero, no change is made. In all cases the (int)
10295 ** variable is set to 1 if the sqlite3session_changeset_size() API is
10296 ** enabled following the current call, or 0 otherwise.
10298 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10299 ** the first table has been attached to the session object.
10301 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10305 #define SQLITE_SESSION_OBJCONFIG_SIZE 1
10308 ** CAPI3REF: Enable Or Disable A Session Object
10309 ** METHOD: sqlite3_session
10311 ** Enable or disable the recording of changes by a session object. When
10312 ** enabled, a session object records changes made to the database. When
10313 ** disabled - it does not. A newly created session object is enabled.
10314 ** Refer to the documentation for [sqlite3session_changeset()] for further
10315 ** details regarding how enabling and disabling a session object affects
10316 ** the eventual changesets.
10318 ** Passing zero to this function disables the session. Passing a value
10319 ** greater than zero enables it. Passing a value less than zero is a
10320 ** no-op, and may be used to query the current state of the session.
10322 ** The return value indicates the final state of the session object: 0 if
10323 ** the session is disabled, or 1 if it is enabled.
10325 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10328 ** CAPI3REF: Set Or Clear the Indirect Change Flag
10329 ** METHOD: sqlite3_session
10331 ** Each change recorded by a session object is marked as either direct or
10332 ** indirect. A change is marked as indirect if either:
10335 ** <li> The session object "indirect" flag is set when the change is
10337 ** <li> The change is made by an SQL trigger or foreign key action
10338 ** instead of directly as a result of a users SQL statement.
10341 ** If a single row is affected by more than one operation within a session,
10342 ** then the change is considered indirect if all operations meet the criteria
10343 ** for an indirect change above, or direct otherwise.
10345 ** This function is used to set, clear or query the session object indirect
10346 ** flag. If the second argument passed to this function is zero, then the
10347 ** indirect flag is cleared. If it is greater than zero, the indirect flag
10348 ** is set. Passing a value less than zero does not modify the current value
10349 ** of the indirect flag, and may be used to query the current state of the
10350 ** indirect flag for the specified session object.
10352 ** The return value indicates the final state of the indirect flag: 0 if
10353 ** it is clear, or 1 if it is set.
10355 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10358 ** CAPI3REF: Attach A Table To A Session Object
10359 ** METHOD: sqlite3_session
10361 ** If argument zTab is not NULL, then it is the name of a table to attach
10362 ** to the session object passed as the first argument. All subsequent changes
10363 ** made to the table while the session object is enabled will be recorded. See
10364 ** documentation for [sqlite3session_changeset()] for further details.
10366 ** Or, if argument zTab is NULL, then changes are recorded for all tables
10367 ** in the database. If additional tables are added to the database (by
10368 ** executing "CREATE TABLE" statements) after this call is made, changes for
10369 ** the new tables are also recorded.
10371 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10372 ** defined as part of their CREATE TABLE statement. It does not matter if the
10373 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10374 ** KEY may consist of a single column, or may be a composite key.
10376 ** It is not an error if the named table does not exist in the database. Nor
10377 ** is it an error if the named table does not have a PRIMARY KEY. However,
10378 ** no changes will be recorded in either of these scenarios.
10380 ** Changes are not recorded for individual rows that have NULL values stored
10381 ** in one or more of their PRIMARY KEY columns.
10383 ** SQLITE_OK is returned if the call completes without error. Or, if an error
10384 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10386 ** <h3>Special sqlite_stat1 Handling</h3>
10388 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10389 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10391 ** CREATE TABLE sqlite_stat1(tbl,idx,stat)
10394 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10395 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10396 ** are recorded for rows for which (idx IS NULL) is true. However, for such
10397 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
10398 ** patchset instead of a NULL value. This allows such changesets to be
10399 ** manipulated by legacy implementations of sqlite3changeset_invert(),
10400 ** concat() and similar.
10402 ** The sqlite3changeset_apply() function automatically converts the
10403 ** zero-length blob back to a NULL value when updating the sqlite_stat1
10404 ** table. However, if the application calls sqlite3changeset_new(),
10405 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10406 ** iterator directly (including on a changeset iterator passed to a
10407 ** conflict-handler callback) then the X'' value is returned. The application
10408 ** must translate X'' to NULL itself if required.
10410 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10411 ** changes made to the sqlite_stat1 table. Legacy versions of the
10412 ** sqlite3changeset_apply() function silently ignore any modifications to the
10413 ** sqlite_stat1 table that are part of a changeset or patchset.
10415 SQLITE_API int sqlite3session_attach(
10416 sqlite3_session *pSession, /* Session object */
10417 const char *zTab /* Table name */
10421 ** CAPI3REF: Set a table filter on a Session Object.
10422 ** METHOD: sqlite3_session
10424 ** The second argument (xFilter) is the "filter callback". For changes to rows
10425 ** in tables that are not attached to the Session object, the filter is called
10426 ** to determine whether changes to the table's rows should be tracked or not.
10427 ** If xFilter returns 0, changes are not tracked. Note that once a table is
10428 ** attached, xFilter will not be called again.
10430 SQLITE_API void sqlite3session_table_filter(
10431 sqlite3_session *pSession, /* Session object */
10433 void *pCtx, /* Copy of third arg to _filter_table() */
10434 const char *zTab /* Table name */
10436 void *pCtx /* First argument passed to xFilter */
10440 ** CAPI3REF: Generate A Changeset From A Session Object
10441 ** METHOD: sqlite3_session
10443 ** Obtain a changeset containing changes to the tables attached to the
10444 ** session object passed as the first argument. If successful,
10445 ** set *ppChangeset to point to a buffer containing the changeset
10446 ** and *pnChangeset to the size of the changeset in bytes before returning
10447 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10448 ** zero and return an SQLite error code.
10450 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10451 ** each representing a change to a single row of an attached table. An INSERT
10452 ** change contains the values of each field of a new database row. A DELETE
10453 ** contains the original values of each field of a deleted database row. An
10454 ** UPDATE change contains the original values of each field of an updated
10455 ** database row along with the updated values for each updated non-primary-key
10456 ** column. It is not possible for an UPDATE change to represent a change that
10457 ** modifies the values of primary key columns. If such a change is made, it
10458 ** is represented in a changeset as a DELETE followed by an INSERT.
10460 ** Changes are not recorded for rows that have NULL values stored in one or
10461 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10462 ** no corresponding change is present in the changesets returned by this
10463 ** function. If an existing row with one or more NULL values stored in
10464 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10465 ** only an INSERT is appears in the changeset. Similarly, if an existing row
10466 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
10467 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10468 ** DELETE change only.
10470 ** The contents of a changeset may be traversed using an iterator created
10471 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
10472 ** a database with a compatible schema using the [sqlite3changeset_apply()]
10475 ** Within a changeset generated by this function, all changes related to a
10476 ** single table are grouped together. In other words, when iterating through
10477 ** a changeset or when applying a changeset to a database, all changes related
10478 ** to a single table are processed before moving on to the next table. Tables
10479 ** are sorted in the same order in which they were attached (or auto-attached)
10480 ** to the sqlite3_session object. The order in which the changes related to
10481 ** a single table are stored is undefined.
10483 ** Following a successful call to this function, it is the responsibility of
10484 ** the caller to eventually free the buffer that *ppChangeset points to using
10485 ** [sqlite3_free()].
10487 ** <h3>Changeset Generation</h3>
10489 ** Once a table has been attached to a session object, the session object
10490 ** records the primary key values of all new rows inserted into the table.
10491 ** It also records the original primary key and other column values of any
10492 ** deleted or updated rows. For each unique primary key value, data is only
10493 ** recorded once - the first time a row with said primary key is inserted,
10494 ** updated or deleted in the lifetime of the session.
10496 ** There is one exception to the previous paragraph: when a row is inserted,
10497 ** updated or deleted, if one or more of its primary key columns contain a
10498 ** NULL value, no record of the change is made.
10500 ** The session object therefore accumulates two types of records - those
10501 ** that consist of primary key values only (created when the user inserts
10502 ** a new record) and those that consist of the primary key values and the
10503 ** original values of other table columns (created when the users deletes
10504 ** or updates a record).
10506 ** When this function is called, the requested changeset is created using
10507 ** both the accumulated records and the current contents of the database
10508 ** file. Specifically:
10511 ** <li> For each record generated by an insert, the database is queried
10512 ** for a row with a matching primary key. If one is found, an INSERT
10513 ** change is added to the changeset. If no such row is found, no change
10514 ** is added to the changeset.
10516 ** <li> For each record generated by an update or delete, the database is
10517 ** queried for a row with a matching primary key. If such a row is
10518 ** found and one or more of the non-primary key fields have been
10519 ** modified from their original values, an UPDATE change is added to
10520 ** the changeset. Or, if no such row is found in the table, a DELETE
10521 ** change is added to the changeset. If there is a row with a matching
10522 ** primary key in the database, but all fields contain their original
10523 ** values, no change is added to the changeset.
10526 ** This means, amongst other things, that if a row is inserted and then later
10527 ** deleted while a session object is active, neither the insert nor the delete
10528 ** will be present in the changeset. Or if a row is deleted and then later a
10529 ** row with the same primary key values inserted while a session object is
10530 ** active, the resulting changeset will contain an UPDATE change instead of
10531 ** a DELETE and an INSERT.
10533 ** When a session object is disabled (see the [sqlite3session_enable()] API),
10534 ** it does not accumulate records when rows are inserted, updated or deleted.
10535 ** This may appear to have some counter-intuitive effects if a single row
10536 ** is written to more than once during a session. For example, if a row
10537 ** is inserted while a session object is enabled, then later deleted while
10538 ** the same session object is disabled, no INSERT record will appear in the
10539 ** changeset, even though the delete took place while the session was disabled.
10540 ** Or, if one field of a row is updated while a session is disabled, and
10541 ** another field of the same row is updated while the session is enabled, the
10542 ** resulting changeset will contain an UPDATE change that updates both fields.
10544 SQLITE_API int sqlite3session_changeset(
10545 sqlite3_session *pSession, /* Session object */
10546 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10547 void **ppChangeset /* OUT: Buffer containing changeset */
10551 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
10552 ** METHOD: sqlite3_session
10554 ** By default, this function always returns 0. For it to return
10555 ** a useful result, the sqlite3_session object must have been configured
10556 ** to enable this API using sqlite3session_object_config() with the
10557 ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
10559 ** When enabled, this function returns an upper limit, in bytes, for the size
10560 ** of the changeset that might be produced if sqlite3session_changeset() were
10561 ** called. The final changeset size might be equal to or smaller than the
10562 ** size in bytes returned by this function.
10564 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
10567 ** CAPI3REF: Load The Difference Between Tables Into A Session
10568 ** METHOD: sqlite3_session
10570 ** If it is not already attached to the session object passed as the first
10571 ** argument, this function attaches table zTbl in the same manner as the
10572 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10573 ** does not have a primary key, this function is a no-op (but does not return
10576 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10577 ** attached to the same database handle as the session object that contains
10578 ** a table compatible with the table attached to the session by this function.
10579 ** A table is considered compatible if it:
10582 ** <li> Has the same name,
10583 ** <li> Has the same set of columns declared in the same order, and
10584 ** <li> Has the same PRIMARY KEY definition.
10587 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10588 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
10589 ** but no changes are added to the session object. As with other session
10590 ** APIs, tables without PRIMARY KEYs are simply ignored.
10592 ** This function adds a set of changes to the session object that could be
10593 ** used to update the table in database zFrom (call this the "from-table")
10594 ** so that its content is the same as the table attached to the session
10595 ** object (call this the "to-table"). Specifically:
10598 ** <li> For each row (primary key) that exists in the to-table but not in
10599 ** the from-table, an INSERT record is added to the session object.
10601 ** <li> For each row (primary key) that exists in the to-table but not in
10602 ** the from-table, a DELETE record is added to the session object.
10604 ** <li> For each row (primary key) that exists in both tables, but features
10605 ** different non-PK values in each, an UPDATE record is added to the
10609 ** To clarify, if this function is called and then a changeset constructed
10610 ** using [sqlite3session_changeset()], then after applying that changeset to
10611 ** database zFrom the contents of the two compatible tables would be
10614 ** It an error if database zFrom does not exist or does not contain the
10615 ** required compatible table.
10617 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
10618 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
10619 ** may be set to point to a buffer containing an English language error
10620 ** message. It is the responsibility of the caller to free this buffer using
10623 SQLITE_API int sqlite3session_diff(
10624 sqlite3_session *pSession,
10625 const char *zFromDb,
10632 ** CAPI3REF: Generate A Patchset From A Session Object
10633 ** METHOD: sqlite3_session
10635 ** The differences between a patchset and a changeset are that:
10638 ** <li> DELETE records consist of the primary key fields only. The
10639 ** original values of other fields are omitted.
10640 ** <li> The original values of any modified fields are omitted from
10644 ** A patchset blob may be used with up to date versions of all
10645 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
10646 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10647 ** attempting to use a patchset blob with old versions of the
10648 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
10650 ** Because the non-primary key "old.*" fields are omitted, no
10651 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10652 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
10653 ** in the same way as for changesets.
10655 ** Changes within a patchset are ordered in the same way as for changesets
10656 ** generated by the sqlite3session_changeset() function (i.e. all changes for
10657 ** a single table are grouped together, tables appear in the order in which
10658 ** they were attached to the session object).
10660 SQLITE_API int sqlite3session_patchset(
10661 sqlite3_session *pSession, /* Session object */
10662 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
10663 void **ppPatchset /* OUT: Buffer containing patchset */
10667 ** CAPI3REF: Test if a changeset has recorded any changes.
10669 ** Return non-zero if no changes to attached tables have been recorded by
10670 ** the session object passed as the first argument. Otherwise, if one or
10671 ** more changes have been recorded, return zero.
10673 ** Even if this function returns zero, it is possible that calling
10674 ** [sqlite3session_changeset()] on the session handle may still return a
10675 ** changeset that contains no changes. This can happen when a row in
10676 ** an attached table is modified and then later on the original values
10677 ** are restored. However, if this function returns non-zero, then it is
10678 ** guaranteed that a call to sqlite3session_changeset() will return a
10679 ** changeset containing zero changes.
10681 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
10684 ** CAPI3REF: Query for the amount of heap memory used by a session object.
10686 ** This API returns the total amount of heap memory in bytes currently
10687 ** used by the session object passed as the only argument.
10689 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
10692 ** CAPI3REF: Create An Iterator To Traverse A Changeset
10693 ** CONSTRUCTOR: sqlite3_changeset_iter
10695 ** Create an iterator used to iterate through the contents of a changeset.
10696 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
10697 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
10698 ** SQLite error code is returned.
10700 ** The following functions can be used to advance and query a changeset
10701 ** iterator created by this function:
10704 ** <li> [sqlite3changeset_next()]
10705 ** <li> [sqlite3changeset_op()]
10706 ** <li> [sqlite3changeset_new()]
10707 ** <li> [sqlite3changeset_old()]
10710 ** It is the responsibility of the caller to eventually destroy the iterator
10711 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
10712 ** changeset (pChangeset) must remain valid until after the iterator is
10715 ** Assuming the changeset blob was created by one of the
10716 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
10717 ** [sqlite3changeset_invert()] functions, all changes within the changeset
10718 ** that apply to a single table are grouped together. This means that when
10719 ** an application iterates through a changeset using an iterator created by
10720 ** this function, all changes that relate to a single table are visited
10721 ** consecutively. There is no chance that the iterator will visit a change
10722 ** the applies to table X, then one for table Y, and then later on visit
10723 ** another change for table X.
10725 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
10726 ** may be modified by passing a combination of
10727 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
10729 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
10730 ** and therefore subject to change.
10732 SQLITE_API int sqlite3changeset_start(
10733 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10734 int nChangeset, /* Size of changeset blob in bytes */
10735 void *pChangeset /* Pointer to blob containing changeset */
10737 SQLITE_API int sqlite3changeset_start_v2(
10738 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10739 int nChangeset, /* Size of changeset blob in bytes */
10740 void *pChangeset, /* Pointer to blob containing changeset */
10741 int flags /* SESSION_CHANGESETSTART_* flags */
10745 ** CAPI3REF: Flags for sqlite3changeset_start_v2
10747 ** The following flags may passed via the 4th parameter to
10748 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10750 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10751 ** Invert the changeset while iterating through it. This is equivalent to
10752 ** inverting a changeset using sqlite3changeset_invert() before applying it.
10753 ** It is an error to specify this flag with a patchset.
10755 #define SQLITE_CHANGESETSTART_INVERT 0x0002
10759 ** CAPI3REF: Advance A Changeset Iterator
10760 ** METHOD: sqlite3_changeset_iter
10762 ** This function may only be used with iterators created by the function
10763 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
10764 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10765 ** is returned and the call has no effect.
10767 ** Immediately after an iterator is created by sqlite3changeset_start(), it
10768 ** does not point to any change in the changeset. Assuming the changeset
10769 ** is not empty, the first call to this function advances the iterator to
10770 ** point to the first change in the changeset. Each subsequent call advances
10771 ** the iterator to point to the next change in the changeset (if any). If
10772 ** no error occurs and the iterator points to a valid change after a call
10773 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10774 ** Otherwise, if all changes in the changeset have already been visited,
10775 ** SQLITE_DONE is returned.
10777 ** If an error occurs, an SQLite error code is returned. Possible error
10778 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10781 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10784 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10785 ** METHOD: sqlite3_changeset_iter
10787 ** The pIter argument passed to this function may either be an iterator
10788 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10789 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10790 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10791 ** is not the case, this function returns [SQLITE_MISUSE].
10793 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
10794 ** outputs are set through these pointers:
10796 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
10797 ** depending on the type of change that the iterator currently points to;
10799 ** *pnCol is set to the number of columns in the table affected by the change; and
10801 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
10802 ** the name of the table affected by the current change. The buffer remains
10803 ** valid until either sqlite3changeset_next() is called on the iterator
10804 ** or until the conflict-handler function returns.
10806 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10807 ** is an indirect change, or false (0) otherwise. See the documentation for
10808 ** [sqlite3session_indirect()] for a description of direct and indirect
10811 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10812 ** SQLite error code is returned. The values of the output variables may not
10813 ** be trusted in this case.
10815 SQLITE_API int sqlite3changeset_op(
10816 sqlite3_changeset_iter *pIter, /* Iterator object */
10817 const char **pzTab, /* OUT: Pointer to table name */
10818 int *pnCol, /* OUT: Number of columns in table */
10819 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10820 int *pbIndirect /* OUT: True for an 'indirect' change */
10824 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
10825 ** METHOD: sqlite3_changeset_iter
10827 ** For each modified table, a changeset includes the following:
10830 ** <li> The number of columns in the table, and
10831 ** <li> Which of those columns make up the tables PRIMARY KEY.
10834 ** This function is used to find which columns comprise the PRIMARY KEY of
10835 ** the table modified by the change that iterator pIter currently points to.
10836 ** If successful, *pabPK is set to point to an array of nCol entries, where
10837 ** nCol is the number of columns in the table. Elements of *pabPK are set to
10838 ** 0x01 if the corresponding column is part of the tables primary key, or
10839 ** 0x00 if it is not.
10841 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10844 ** If this function is called when the iterator does not point to a valid
10845 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10846 ** SQLITE_OK is returned and the output variables populated as described
10849 SQLITE_API int sqlite3changeset_pk(
10850 sqlite3_changeset_iter *pIter, /* Iterator object */
10851 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10852 int *pnCol /* OUT: Number of entries in output array */
10856 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10857 ** METHOD: sqlite3_changeset_iter
10859 ** The pIter argument passed to this function may either be an iterator
10860 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10861 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10862 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10863 ** Furthermore, it may only be called if the type of change that the iterator
10864 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10865 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10867 ** Argument iVal must be greater than or equal to 0, and less than the number
10868 ** of columns in the table affected by the current change. Otherwise,
10869 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10871 ** If successful, this function sets *ppValue to point to a protected
10872 ** sqlite3_value object containing the iVal'th value from the vector of
10873 ** original row values stored as part of the UPDATE or DELETE change and
10874 ** returns SQLITE_OK. The name of the function comes from the fact that this
10875 ** is similar to the "old.*" columns available to update or delete triggers.
10877 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10878 ** is returned and *ppValue is set to NULL.
10880 SQLITE_API int sqlite3changeset_old(
10881 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10882 int iVal, /* Column number */
10883 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10887 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10888 ** METHOD: sqlite3_changeset_iter
10890 ** The pIter argument passed to this function may either be an iterator
10891 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10892 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
10893 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10894 ** Furthermore, it may only be called if the type of change that the iterator
10895 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10896 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10898 ** Argument iVal must be greater than or equal to 0, and less than the number
10899 ** of columns in the table affected by the current change. Otherwise,
10900 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10902 ** If successful, this function sets *ppValue to point to a protected
10903 ** sqlite3_value object containing the iVal'th value from the vector of
10904 ** new row values stored as part of the UPDATE or INSERT change and
10905 ** returns SQLITE_OK. If the change is an UPDATE and does not include
10906 ** a new value for the requested column, *ppValue is set to NULL and
10907 ** SQLITE_OK returned. The name of the function comes from the fact that
10908 ** this is similar to the "new.*" columns available to update or delete
10911 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10912 ** is returned and *ppValue is set to NULL.
10914 SQLITE_API int sqlite3changeset_new(
10915 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10916 int iVal, /* Column number */
10917 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10921 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10922 ** METHOD: sqlite3_changeset_iter
10924 ** This function should only be used with iterator objects passed to a
10925 ** conflict-handler callback by [sqlite3changeset_apply()] with either
10926 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10927 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10930 ** Argument iVal must be greater than or equal to 0, and less than the number
10931 ** of columns in the table affected by the current change. Otherwise,
10932 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10934 ** If successful, this function sets *ppValue to point to a protected
10935 ** sqlite3_value object containing the iVal'th value from the
10936 ** "conflicting row" associated with the current conflict-handler callback
10937 ** and returns SQLITE_OK.
10939 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
10940 ** is returned and *ppValue is set to NULL.
10942 SQLITE_API int sqlite3changeset_conflict(
10943 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10944 int iVal, /* Column number */
10945 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10949 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10950 ** METHOD: sqlite3_changeset_iter
10952 ** This function may only be called with an iterator passed to an
10953 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10954 ** it sets the output variable to the total number of known foreign key
10955 ** violations in the destination database and returns SQLITE_OK.
10957 ** In all other cases this function returns SQLITE_MISUSE.
10959 SQLITE_API int sqlite3changeset_fk_conflicts(
10960 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10961 int *pnOut /* OUT: Number of FK violations */
10966 ** CAPI3REF: Finalize A Changeset Iterator
10967 ** METHOD: sqlite3_changeset_iter
10969 ** This function is used to finalize an iterator allocated with
10970 ** [sqlite3changeset_start()].
10972 ** This function should only be called on iterators created using the
10973 ** [sqlite3changeset_start()] function. If an application calls this
10974 ** function with an iterator passed to a conflict-handler by
10975 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10976 ** call has no effect.
10978 ** If an error was encountered within a call to an sqlite3changeset_xxx()
10979 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10980 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10981 ** to that error is returned by this function. Otherwise, SQLITE_OK is
10982 ** returned. This is to allow the following pattern (pseudo-code):
10985 ** sqlite3changeset_start();
10986 ** while( SQLITE_ROW==sqlite3changeset_next() ){
10987 ** // Do something with change.
10989 ** rc = sqlite3changeset_finalize();
10990 ** if( rc!=SQLITE_OK ){
10991 ** // An error has occurred
10995 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10998 ** CAPI3REF: Invert A Changeset
11000 ** This function is used to "invert" a changeset object. Applying an inverted
11001 ** changeset to a database reverses the effects of applying the uninverted
11002 ** changeset. Specifically:
11005 ** <li> Each DELETE change is changed to an INSERT, and
11006 ** <li> Each INSERT change is changed to a DELETE, and
11007 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11010 ** This function does not change the order in which changes appear within
11011 ** the changeset. It merely reverses the sense of each individual change.
11013 ** If successful, a pointer to a buffer containing the inverted changeset
11014 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11015 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11016 ** zeroed and an SQLite error code returned.
11018 ** It is the responsibility of the caller to eventually call sqlite3_free()
11019 ** on the *ppOut pointer to free the buffer allocation following a successful
11020 ** call to this function.
11022 ** WARNING/TODO: This function currently assumes that the input is a valid
11023 ** changeset. If it is not, the results are undefined.
11025 SQLITE_API int sqlite3changeset_invert(
11026 int nIn, const void *pIn, /* Input changeset */
11027 int *pnOut, void **ppOut /* OUT: Inverse of input */
11031 ** CAPI3REF: Concatenate Two Changeset Objects
11033 ** This function is used to concatenate two changesets, A and B, into a
11034 ** single changeset. The result is a changeset equivalent to applying
11035 ** changeset A followed by changeset B.
11037 ** This function combines the two input changesets using an
11038 ** sqlite3_changegroup object. Calling it produces similar results as the
11039 ** following code fragment:
11042 ** sqlite3_changegroup *pGrp;
11043 ** rc = sqlite3_changegroup_new(&pGrp);
11044 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11045 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11046 ** if( rc==SQLITE_OK ){
11047 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11054 ** Refer to the sqlite3_changegroup documentation below for details.
11056 SQLITE_API int sqlite3changeset_concat(
11057 int nA, /* Number of bytes in buffer pA */
11058 void *pA, /* Pointer to buffer containing changeset A */
11059 int nB, /* Number of bytes in buffer pB */
11060 void *pB, /* Pointer to buffer containing changeset B */
11061 int *pnOut, /* OUT: Number of bytes in output changeset */
11062 void **ppOut /* OUT: Buffer containing output changeset */
11067 ** CAPI3REF: Changegroup Handle
11069 ** A changegroup is an object used to combine two or more
11070 ** [changesets] or [patchsets]
11072 typedef struct sqlite3_changegroup sqlite3_changegroup;
11075 ** CAPI3REF: Create A New Changegroup Object
11076 ** CONSTRUCTOR: sqlite3_changegroup
11078 ** An sqlite3_changegroup object is used to combine two or more changesets
11079 ** (or patchsets) into a single changeset (or patchset). A single changegroup
11080 ** object may combine changesets or patchsets, but not both. The output is
11081 ** always in the same format as the input.
11083 ** If successful, this function returns SQLITE_OK and populates (*pp) with
11084 ** a pointer to a new sqlite3_changegroup object before returning. The caller
11085 ** should eventually free the returned object using a call to
11086 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11087 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11089 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
11092 ** <li> It is created using a call to sqlite3changegroup_new().
11094 ** <li> Zero or more changesets (or patchsets) are added to the object
11095 ** by calling sqlite3changegroup_add().
11097 ** <li> The result of combining all input changesets together is obtained
11098 ** by the application via a call to sqlite3changegroup_output().
11100 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
11103 ** Any number of calls to add() and output() may be made between the calls to
11104 ** new() and delete(), and in any order.
11106 ** As well as the regular sqlite3changegroup_add() and
11107 ** sqlite3changegroup_output() functions, also available are the streaming
11108 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11110 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11113 ** CAPI3REF: Add A Changeset To A Changegroup
11114 ** METHOD: sqlite3_changegroup
11116 ** Add all changes within the changeset (or patchset) in buffer pData (size
11117 ** nData bytes) to the changegroup.
11119 ** If the buffer contains a patchset, then all prior calls to this function
11120 ** on the same changegroup object must also have specified patchsets. Or, if
11121 ** the buffer contains a changeset, so must have the earlier calls to this
11122 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11123 ** to the changegroup.
11125 ** Rows within the changeset and changegroup are identified by the values in
11126 ** their PRIMARY KEY columns. A change in the changeset is considered to
11127 ** apply to the same row as a change already present in the changegroup if
11128 ** the two rows have the same primary key.
11130 ** Changes to rows that do not already appear in the changegroup are
11131 ** simply copied into it. Or, if both the new changeset and the changegroup
11132 ** contain changes that apply to a single row, the final contents of the
11133 ** changegroup depends on the type of each change, as follows:
11135 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11136 ** <tr><th style="white-space:pre">Existing Change </th>
11137 ** <th style="white-space:pre">New Change </th>
11138 ** <th>Output Change
11139 ** <tr><td>INSERT <td>INSERT <td>
11140 ** The new change is ignored. This case does not occur if the new
11141 ** changeset was recorded immediately after the changesets already
11142 ** added to the changegroup.
11143 ** <tr><td>INSERT <td>UPDATE <td>
11144 ** The INSERT change remains in the changegroup. The values in the
11145 ** INSERT change are modified as if the row was inserted by the
11146 ** existing change and then updated according to the new change.
11147 ** <tr><td>INSERT <td>DELETE <td>
11148 ** The existing INSERT is removed from the changegroup. The DELETE is
11150 ** <tr><td>UPDATE <td>INSERT <td>
11151 ** The new change is ignored. This case does not occur if the new
11152 ** changeset was recorded immediately after the changesets already
11153 ** added to the changegroup.
11154 ** <tr><td>UPDATE <td>UPDATE <td>
11155 ** The existing UPDATE remains within the changegroup. It is amended
11156 ** so that the accompanying values are as if the row was updated once
11157 ** by the existing change and then again by the new change.
11158 ** <tr><td>UPDATE <td>DELETE <td>
11159 ** The existing UPDATE is replaced by the new DELETE within the
11161 ** <tr><td>DELETE <td>INSERT <td>
11162 ** If one or more of the column values in the row inserted by the
11163 ** new change differ from those in the row deleted by the existing
11164 ** change, the existing DELETE is replaced by an UPDATE within the
11165 ** changegroup. Otherwise, if the inserted row is exactly the same
11166 ** as the deleted row, the existing DELETE is simply discarded.
11167 ** <tr><td>DELETE <td>UPDATE <td>
11168 ** The new change is ignored. This case does not occur if the new
11169 ** changeset was recorded immediately after the changesets already
11170 ** added to the changegroup.
11171 ** <tr><td>DELETE <td>DELETE <td>
11172 ** The new change is ignored. This case does not occur if the new
11173 ** changeset was recorded immediately after the changesets already
11174 ** added to the changegroup.
11177 ** If the new changeset contains changes to a table that is already present
11178 ** in the changegroup, then the number of columns and the position of the
11179 ** primary key columns for the table must be consistent. If this is not the
11180 ** case, this function fails with SQLITE_SCHEMA. If the input changeset
11181 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11182 ** returned. Or, if an out-of-memory condition occurs during processing, this
11183 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11184 ** of the final contents of the changegroup is undefined.
11186 ** If no error occurs, SQLITE_OK is returned.
11188 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11191 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11192 ** METHOD: sqlite3_changegroup
11194 ** Obtain a buffer containing a changeset (or patchset) representing the
11195 ** current contents of the changegroup. If the inputs to the changegroup
11196 ** were themselves changesets, the output is a changeset. Or, if the
11197 ** inputs were patchsets, the output is also a patchset.
11199 ** As with the output of the sqlite3session_changeset() and
11200 ** sqlite3session_patchset() functions, all changes related to a single
11201 ** table are grouped together in the output of this function. Tables appear
11202 ** in the same order as for the very first changeset added to the changegroup.
11203 ** If the second or subsequent changesets added to the changegroup contain
11204 ** changes for tables that do not appear in the first changeset, they are
11205 ** appended onto the end of the output changeset, again in the order in
11206 ** which they are first encountered.
11208 ** If an error occurs, an SQLite error code is returned and the output
11209 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11210 ** is returned and the output variables are set to the size of and a
11211 ** pointer to the output buffer, respectively. In this case it is the
11212 ** responsibility of the caller to eventually free the buffer using a
11213 ** call to sqlite3_free().
11215 SQLITE_API int sqlite3changegroup_output(
11216 sqlite3_changegroup*,
11217 int *pnData, /* OUT: Size of output buffer in bytes */
11218 void **ppData /* OUT: Pointer to output buffer */
11222 ** CAPI3REF: Delete A Changegroup Object
11223 ** DESTRUCTOR: sqlite3_changegroup
11225 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11228 ** CAPI3REF: Apply A Changeset To A Database
11230 ** Apply a changeset or patchset to a database. These functions attempt to
11231 ** update the "main" database attached to handle db with the changes found in
11232 ** the changeset passed via the second and third arguments.
11234 ** The fourth argument (xFilter) passed to these functions is the "filter
11235 ** callback". If it is not NULL, then for each table affected by at least one
11236 ** change in the changeset, the filter callback is invoked with
11237 ** the table name as the second argument, and a copy of the context pointer
11238 ** passed as the sixth argument as the first. If the "filter callback"
11239 ** returns zero, then no attempt is made to apply any changes to the table.
11240 ** Otherwise, if the return value is non-zero or the xFilter argument to
11241 ** is NULL, all changes related to the table are attempted.
11243 ** For each table that is not excluded by the filter callback, this function
11244 ** tests that the target database contains a compatible table. A table is
11245 ** considered compatible if all of the following are true:
11248 ** <li> The table has the same name as the name recorded in the
11250 ** <li> The table has at least as many columns as recorded in the
11252 ** <li> The table has primary key columns in the same position as
11253 ** recorded in the changeset.
11256 ** If there is no compatible table, it is not an error, but none of the
11257 ** changes associated with the table are applied. A warning message is issued
11258 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11259 ** one such warning is issued for each table in the changeset.
11261 ** For each change for which there is a compatible table, an attempt is made
11262 ** to modify the table contents according to the UPDATE, INSERT or DELETE
11263 ** change. If a change cannot be applied cleanly, the conflict handler
11264 ** function passed as the fifth argument to sqlite3changeset_apply() may be
11265 ** invoked. A description of exactly when the conflict handler is invoked for
11266 ** each type of change is below.
11268 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11269 ** of passing anything other than a valid function pointer as the xConflict
11270 ** argument are undefined.
11272 ** Each time the conflict handler function is invoked, it must return one
11273 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11274 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11275 ** if the second argument passed to the conflict handler is either
11276 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11277 ** returns an illegal value, any changes already made are rolled back and
11278 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11279 ** actions are taken by sqlite3changeset_apply() depending on the value
11280 ** returned by each invocation of the conflict-handler function. Refer to
11281 ** the documentation for the three
11282 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
11285 ** <dt>DELETE Changes<dd>
11286 ** For each DELETE change, the function checks if the target database
11287 ** contains a row with the same primary key value (or values) as the
11288 ** original row values stored in the changeset. If it does, and the values
11289 ** stored in all non-primary key columns also match the values stored in
11290 ** the changeset the row is deleted from the target database.
11292 ** If a row with matching primary key values is found, but one or more of
11293 ** the non-primary key fields contains a value different from the original
11294 ** row value stored in the changeset, the conflict-handler function is
11295 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11296 ** database table has more columns than are recorded in the changeset,
11297 ** only the values of those non-primary key fields are compared against
11298 ** the current database contents - any trailing database table columns
11301 ** If no row with matching primary key values is found in the database,
11302 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11303 ** passed as the second argument.
11305 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11306 ** (which can only happen if a foreign key constraint is violated), the
11307 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11308 ** passed as the second argument. This includes the case where the DELETE
11309 ** operation is attempted because an earlier call to the conflict handler
11310 ** function returned [SQLITE_CHANGESET_REPLACE].
11312 ** <dt>INSERT Changes<dd>
11313 ** For each INSERT change, an attempt is made to insert the new row into
11314 ** the database. If the changeset row contains fewer fields than the
11315 ** database table, the trailing fields are populated with their default
11318 ** If the attempt to insert the row fails because the database already
11319 ** contains a row with the same primary key values, the conflict handler
11320 ** function is invoked with the second argument set to
11321 ** [SQLITE_CHANGESET_CONFLICT].
11323 ** If the attempt to insert the row fails because of some other constraint
11324 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11325 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11326 ** This includes the case where the INSERT operation is re-attempted because
11327 ** an earlier call to the conflict handler function returned
11328 ** [SQLITE_CHANGESET_REPLACE].
11330 ** <dt>UPDATE Changes<dd>
11331 ** For each UPDATE change, the function checks if the target database
11332 ** contains a row with the same primary key value (or values) as the
11333 ** original row values stored in the changeset. If it does, and the values
11334 ** stored in all modified non-primary key columns also match the values
11335 ** stored in the changeset the row is updated within the target database.
11337 ** If a row with matching primary key values is found, but one or more of
11338 ** the modified non-primary key fields contains a value different from an
11339 ** original row value stored in the changeset, the conflict-handler function
11340 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11341 ** UPDATE changes only contain values for non-primary key fields that are
11342 ** to be modified, only those fields need to match the original values to
11343 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11345 ** If no row with matching primary key values is found in the database,
11346 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11347 ** passed as the second argument.
11349 ** If the UPDATE operation is attempted, but SQLite returns
11350 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11351 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11352 ** This includes the case where the UPDATE operation is attempted after
11353 ** an earlier call to the conflict handler function returned
11354 ** [SQLITE_CHANGESET_REPLACE].
11357 ** It is safe to execute SQL statements, including those that write to the
11358 ** table that the callback related to, from within the xConflict callback.
11359 ** This can be used to further customize the application's conflict
11360 ** resolution strategy.
11362 ** All changes made by these functions are enclosed in a savepoint transaction.
11363 ** If any other error (aside from a constraint failure when attempting to
11364 ** write to the target database) occurs, then the savepoint transaction is
11365 ** rolled back, restoring the target database to its original state, and an
11366 ** SQLite error code returned.
11368 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11369 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11370 ** may set (*ppRebase) to point to a "rebase" that may be used with the
11371 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11372 ** is set to the size of the buffer in bytes. It is the responsibility of the
11373 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
11374 ** is only allocated and populated if one or more conflicts were encountered
11375 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
11376 ** APIs for further details.
11378 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11379 ** may be modified by passing a combination of
11380 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11382 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11383 ** and therefore subject to change.
11385 SQLITE_API int sqlite3changeset_apply(
11386 sqlite3 *db, /* Apply change to "main" db of this handle */
11387 int nChangeset, /* Size of changeset in bytes */
11388 void *pChangeset, /* Changeset blob */
11390 void *pCtx, /* Copy of sixth arg to _apply() */
11391 const char *zTab /* Table name */
11394 void *pCtx, /* Copy of sixth arg to _apply() */
11395 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11396 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11398 void *pCtx /* First argument passed to xConflict */
11400 SQLITE_API int sqlite3changeset_apply_v2(
11401 sqlite3 *db, /* Apply change to "main" db of this handle */
11402 int nChangeset, /* Size of changeset in bytes */
11403 void *pChangeset, /* Changeset blob */
11405 void *pCtx, /* Copy of sixth arg to _apply() */
11406 const char *zTab /* Table name */
11409 void *pCtx, /* Copy of sixth arg to _apply() */
11410 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11411 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11413 void *pCtx, /* First argument passed to xConflict */
11414 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11415 int flags /* SESSION_CHANGESETAPPLY_* flags */
11419 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
11421 ** The following flags may passed via the 9th parameter to
11422 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11425 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11426 ** Usually, the sessions module encloses all operations performed by
11427 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11428 ** SAVEPOINT is committed if the changeset or patchset is successfully
11429 ** applied, or rolled back if an error occurs. Specifying this flag
11430 ** causes the sessions module to omit this savepoint. In this case, if the
11431 ** caller has an open transaction or savepoint when apply_v2() is called,
11432 ** it may revert the partially applied changeset by rolling it back.
11434 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11435 ** Invert the changeset before applying it. This is equivalent to inverting
11436 ** a changeset using sqlite3changeset_invert() before applying it. It is
11437 ** an error to specify this flag with a patchset.
11439 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11440 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11443 ** CAPI3REF: Constants Passed To The Conflict Handler
11445 ** Values that may be passed as the second argument to a conflict-handler.
11448 ** <dt>SQLITE_CHANGESET_DATA<dd>
11449 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
11450 ** when processing a DELETE or UPDATE change if a row with the required
11451 ** PRIMARY KEY fields is present in the database, but one or more other
11452 ** (non primary-key) fields modified by the update do not contain the
11453 ** expected "before" values.
11455 ** The conflicting row, in this case, is the database row with the matching
11458 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11459 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11460 ** argument when processing a DELETE or UPDATE change if a row with the
11461 ** required PRIMARY KEY fields is not present in the database.
11463 ** There is no conflicting row in this case. The results of invoking the
11464 ** sqlite3changeset_conflict() API are undefined.
11466 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11467 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
11468 ** handler while processing an INSERT change if the operation would result
11469 ** in duplicate primary key values.
11471 ** The conflicting row in this case is the database row with the matching
11474 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11475 ** If foreign key handling is enabled, and applying a changeset leaves the
11476 ** database in a state containing foreign key violations, the conflict
11477 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11478 ** exactly once before the changeset is committed. If the conflict handler
11479 ** returns CHANGESET_OMIT, the changes, including those that caused the
11480 ** foreign key constraint violation, are committed. Or, if it returns
11481 ** CHANGESET_ABORT, the changeset is rolled back.
11483 ** No current or conflicting row information is provided. The only function
11484 ** it is possible to call on the supplied sqlite3_changeset_iter handle
11485 ** is sqlite3changeset_fk_conflicts().
11487 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11488 ** If any other constraint violation occurs while applying a change (i.e.
11489 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11490 ** invoked with CHANGESET_CONSTRAINT as the second argument.
11492 ** There is no conflicting row in this case. The results of invoking the
11493 ** sqlite3changeset_conflict() API are undefined.
11497 #define SQLITE_CHANGESET_DATA 1
11498 #define SQLITE_CHANGESET_NOTFOUND 2
11499 #define SQLITE_CHANGESET_CONFLICT 3
11500 #define SQLITE_CHANGESET_CONSTRAINT 4
11501 #define SQLITE_CHANGESET_FOREIGN_KEY 5
11504 ** CAPI3REF: Constants Returned By The Conflict Handler
11506 ** A conflict handler callback must return one of the following three values.
11509 ** <dt>SQLITE_CHANGESET_OMIT<dd>
11510 ** If a conflict handler returns this value no special action is taken. The
11511 ** change that caused the conflict is not applied. The session module
11512 ** continues to the next change in the changeset.
11514 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
11515 ** This value may only be returned if the second argument to the conflict
11516 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11517 ** is not the case, any changes applied so far are rolled back and the
11518 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11520 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11521 ** handler, then the conflicting row is either updated or deleted, depending
11522 ** on the type of change.
11524 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11525 ** handler, then the conflicting row is removed from the database and a
11526 ** second attempt to apply the change is made. If this second attempt fails,
11527 ** the original row is restored to the database before continuing.
11529 ** <dt>SQLITE_CHANGESET_ABORT<dd>
11530 ** If this value is returned, any changes applied so far are rolled back
11531 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11534 #define SQLITE_CHANGESET_OMIT 0
11535 #define SQLITE_CHANGESET_REPLACE 1
11536 #define SQLITE_CHANGESET_ABORT 2
11539 ** CAPI3REF: Rebasing changesets
11542 ** Suppose there is a site hosting a database in state S0. And that
11543 ** modifications are made that move that database to state S1 and a
11544 ** changeset recorded (the "local" changeset). Then, a changeset based
11545 ** on S0 is received from another site (the "remote" changeset) and
11546 ** applied to the database. The database is then in state
11547 ** (S1+"remote"), where the exact state depends on any conflict
11548 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
11549 ** Rebasing a changeset is to update it to take those conflict
11550 ** resolution decisions into account, so that the same conflicts
11551 ** do not have to be resolved elsewhere in the network.
11553 ** For example, if both the local and remote changesets contain an
11554 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11556 ** local: INSERT INTO t1 VALUES(1, 'v1');
11557 ** remote: INSERT INTO t1 VALUES(1, 'v2');
11559 ** and the conflict resolution is REPLACE, then the INSERT change is
11560 ** removed from the local changeset (it was overridden). Or, if the
11561 ** conflict resolution was "OMIT", then the local changeset is modified
11562 ** to instead contain:
11564 ** UPDATE t1 SET b = 'v2' WHERE a=1;
11566 ** Changes within the local changeset are rebased as follows:
11569 ** <dt>Local INSERT<dd>
11570 ** This may only conflict with a remote INSERT. If the conflict
11571 ** resolution was OMIT, then add an UPDATE change to the rebased
11572 ** changeset. Or, if the conflict resolution was REPLACE, add
11573 ** nothing to the rebased changeset.
11575 ** <dt>Local DELETE<dd>
11576 ** This may conflict with a remote UPDATE or DELETE. In both cases the
11577 ** only possible resolution is OMIT. If the remote operation was a
11578 ** DELETE, then add no change to the rebased changeset. If the remote
11579 ** operation was an UPDATE, then the old.* fields of change are updated
11580 ** to reflect the new.* values in the UPDATE.
11582 ** <dt>Local UPDATE<dd>
11583 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
11584 ** with a DELETE, and the conflict resolution was OMIT, then the update
11585 ** is changed into an INSERT. Any undefined values in the new.* record
11586 ** from the update change are filled in using the old.* values from
11587 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11588 ** the UPDATE change is simply omitted from the rebased changeset.
11590 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
11591 ** the old.* values are rebased using the new.* values in the remote
11592 ** change. Or, if the resolution is REPLACE, then the change is copied
11593 ** into the rebased changeset with updates to columns also updated by
11594 ** the conflicting remote UPDATE removed. If this means no columns would
11595 ** be updated, the change is omitted.
11598 ** A local change may be rebased against multiple remote changes
11599 ** simultaneously. If a single key is modified by multiple remote
11600 ** changesets, they are combined as follows before the local changeset
11604 ** <li> If there has been one or more REPLACE resolutions on a
11605 ** key, it is rebased according to a REPLACE.
11607 ** <li> If there have been no REPLACE resolutions on a key, then
11608 ** the local changeset is rebased according to the most recent
11609 ** of the OMIT resolutions.
11612 ** Note that conflict resolutions from multiple remote changesets are
11613 ** combined on a per-field basis, not per-row. This means that in the
11614 ** case of multiple remote UPDATE operations, some fields of a single
11615 ** local change may be rebased for REPLACE while others are rebased for
11618 ** In order to rebase a local changeset, the remote changeset must first
11619 ** be applied to the local database using sqlite3changeset_apply_v2() and
11620 ** the buffer of rebase information captured. Then:
11623 ** <li> An sqlite3_rebaser object is created by calling
11624 ** sqlite3rebaser_create().
11625 ** <li> The new object is configured with the rebase buffer obtained from
11626 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11627 ** If the local changeset is to be rebased against multiple remote
11628 ** changesets, then sqlite3rebaser_configure() should be called
11629 ** multiple times, in the same order that the multiple
11630 ** sqlite3changeset_apply_v2() calls were made.
11631 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11632 ** <li> The sqlite3_rebaser object is deleted by calling
11633 ** sqlite3rebaser_delete().
11636 typedef struct sqlite3_rebaser sqlite3_rebaser;
11639 ** CAPI3REF: Create a changeset rebaser object.
11642 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11643 ** point to the new object and return SQLITE_OK. Otherwise, if an error
11644 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11647 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11650 ** CAPI3REF: Configure a changeset rebaser object.
11653 ** Configure the changeset rebaser object to rebase changesets according
11654 ** to the conflict resolutions described by buffer pRebase (size nRebase
11655 ** bytes), which must have been obtained from a previous call to
11656 ** sqlite3changeset_apply_v2().
11658 SQLITE_API int sqlite3rebaser_configure(
11660 int nRebase, const void *pRebase
11664 ** CAPI3REF: Rebase a changeset
11667 ** Argument pIn must point to a buffer containing a changeset nIn bytes
11668 ** in size. This function allocates and populates a buffer with a copy
11669 ** of the changeset rebased according to the configuration of the
11670 ** rebaser object passed as the first argument. If successful, (*ppOut)
11671 ** is set to point to the new buffer containing the rebased changeset and
11672 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
11673 ** responsibility of the caller to eventually free the new buffer using
11674 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
11675 ** are set to zero and an SQLite error code returned.
11677 SQLITE_API int sqlite3rebaser_rebase(
11679 int nIn, const void *pIn,
11680 int *pnOut, void **ppOut
11684 ** CAPI3REF: Delete a changeset rebaser object.
11687 ** Delete the changeset rebaser object and all associated resources. There
11688 ** should be one call to this function for each successful invocation
11689 ** of sqlite3rebaser_create().
11691 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
11694 ** CAPI3REF: Streaming Versions of API functions.
11696 ** The six streaming API xxx_strm() functions serve similar purposes to the
11697 ** corresponding non-streaming API functions:
11699 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11700 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
11701 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
11702 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
11703 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
11704 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
11705 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
11706 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
11707 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
11710 ** Non-streaming functions that accept changesets (or patchsets) as input
11711 ** require that the entire changeset be stored in a single buffer in memory.
11712 ** Similarly, those that return a changeset or patchset do so by returning
11713 ** a pointer to a single large buffer allocated using sqlite3_malloc().
11714 ** Normally this is convenient. However, if an application running in a
11715 ** low-memory environment is required to handle very large changesets, the
11716 ** large contiguous memory allocations required can become onerous.
11718 ** In order to avoid this problem, instead of a single large buffer, input
11719 ** is passed to a streaming API functions by way of a callback function that
11720 ** the sessions module invokes to incrementally request input data as it is
11721 ** required. In all cases, a pair of API function parameters such as
11724 ** int nChangeset,
11725 ** void *pChangeset,
11731 ** int (*xInput)(void *pIn, void *pData, int *pnData),
11732 ** void *pIn,
11735 ** Each time the xInput callback is invoked by the sessions module, the first
11736 ** argument passed is a copy of the supplied pIn context pointer. The second
11737 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
11738 ** error occurs the xInput method should copy up to (*pnData) bytes of data
11739 ** into the buffer and set (*pnData) to the actual number of bytes copied
11740 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11741 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
11742 ** error code should be returned. In all cases, if an xInput callback returns
11743 ** an error, all processing is abandoned and the streaming API function
11744 ** returns a copy of the error code to the caller.
11746 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11747 ** invoked by the sessions module at any point during the lifetime of the
11748 ** iterator. If such an xInput callback returns an error, the iterator enters
11749 ** an error state, whereby all subsequent calls to iterator functions
11750 ** immediately fail with the same error code as returned by xInput.
11752 ** Similarly, streaming API functions that return changesets (or patchsets)
11753 ** return them in chunks by way of a callback function instead of via a
11754 ** pointer to a single large buffer. In this case, a pair of parameters such
11758 ** int *pnChangeset,
11759 ** void **ppChangeset,
11765 ** int (*xOutput)(void *pOut, const void *pData, int nData),
11766 ** void *pOut
11769 ** The xOutput callback is invoked zero or more times to return data to
11770 ** the application. The first parameter passed to each call is a copy of the
11771 ** pOut pointer supplied by the application. The second parameter, pData,
11772 ** points to a buffer nData bytes in size containing the chunk of output
11773 ** data being returned. If the xOutput callback successfully processes the
11774 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11775 ** it should return some other SQLite error code. In this case processing
11776 ** is immediately abandoned and the streaming API function returns a copy
11777 ** of the xOutput error code to the application.
11779 ** The sessions module never invokes an xOutput callback with the third
11780 ** parameter set to a value less than or equal to zero. Other than this,
11781 ** no guarantees are made as to the size of the chunks of data returned.
11783 SQLITE_API int sqlite3changeset_apply_strm(
11784 sqlite3 *db, /* Apply change to "main" db of this handle */
11785 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11786 void *pIn, /* First arg for xInput */
11788 void *pCtx, /* Copy of sixth arg to _apply() */
11789 const char *zTab /* Table name */
11792 void *pCtx, /* Copy of sixth arg to _apply() */
11793 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11794 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11796 void *pCtx /* First argument passed to xConflict */
11798 SQLITE_API int sqlite3changeset_apply_v2_strm(
11799 sqlite3 *db, /* Apply change to "main" db of this handle */
11800 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11801 void *pIn, /* First arg for xInput */
11803 void *pCtx, /* Copy of sixth arg to _apply() */
11804 const char *zTab /* Table name */
11807 void *pCtx, /* Copy of sixth arg to _apply() */
11808 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11809 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11811 void *pCtx, /* First argument passed to xConflict */
11812 void **ppRebase, int *pnRebase,
11815 SQLITE_API int sqlite3changeset_concat_strm(
11816 int (*xInputA)(void *pIn, void *pData, int *pnData),
11818 int (*xInputB)(void *pIn, void *pData, int *pnData),
11820 int (*xOutput)(void *pOut, const void *pData, int nData),
11823 SQLITE_API int sqlite3changeset_invert_strm(
11824 int (*xInput)(void *pIn, void *pData, int *pnData),
11826 int (*xOutput)(void *pOut, const void *pData, int nData),
11829 SQLITE_API int sqlite3changeset_start_strm(
11830 sqlite3_changeset_iter **pp,
11831 int (*xInput)(void *pIn, void *pData, int *pnData),
11834 SQLITE_API int sqlite3changeset_start_v2_strm(
11835 sqlite3_changeset_iter **pp,
11836 int (*xInput)(void *pIn, void *pData, int *pnData),
11840 SQLITE_API int sqlite3session_changeset_strm(
11841 sqlite3_session *pSession,
11842 int (*xOutput)(void *pOut, const void *pData, int nData),
11845 SQLITE_API int sqlite3session_patchset_strm(
11846 sqlite3_session *pSession,
11847 int (*xOutput)(void *pOut, const void *pData, int nData),
11850 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11851 int (*xInput)(void *pIn, void *pData, int *pnData),
11854 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11855 int (*xOutput)(void *pOut, const void *pData, int nData),
11858 SQLITE_API int sqlite3rebaser_rebase_strm(
11859 sqlite3_rebaser *pRebaser,
11860 int (*xInput)(void *pIn, void *pData, int *pnData),
11862 int (*xOutput)(void *pOut, const void *pData, int nData),
11867 ** CAPI3REF: Configure global parameters
11869 ** The sqlite3session_config() interface is used to make global configuration
11870 ** changes to the sessions module in order to tune it to the specific needs
11871 ** of the application.
11873 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
11874 ** while any other thread is inside any other sessions method then the
11875 ** results are undefined. Furthermore, if it is invoked after any sessions
11876 ** related objects have been created, the results are also undefined.
11878 ** The first argument to the sqlite3session_config() function must be one
11879 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11880 ** interpretation of the (void*) value passed as the second parameter and
11881 ** the effect of calling this function depends on the value of the first
11885 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11886 ** By default, the sessions module streaming interfaces attempt to input
11887 ** and output data in approximately 1 KiB chunks. This operand may be used
11888 ** to set and query the value of this configuration setting. The pointer
11889 ** passed as the second argument must point to a value of type (int).
11890 ** If this value is greater than 0, it is used as the new streaming data
11891 ** chunk size for both input and output. Before returning, the (int) value
11892 ** pointed to by pArg is set to the final value of the streaming interface
11896 ** This function returns SQLITE_OK if successful, or an SQLite error code
11899 SQLITE_API int sqlite3session_config(int op, void *pArg);
11902 ** CAPI3REF: Values for sqlite3session_config().
11904 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
11907 ** Make sure we can call this stuff from C++.
11913 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11915 /******** End of sqlite3session.h *********/
11916 /******** Begin file fts5.h *********/
11920 ** The author disclaims copyright to this source code. In place of
11921 ** a legal notice, here is a blessing:
11923 ** May you do good and not evil.
11924 ** May you find forgiveness for yourself and forgive others.
11925 ** May you share freely, never taking more than you give.
11927 ******************************************************************************
11929 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
11930 ** FTS5 may be extended with:
11932 ** * custom tokenizers, and
11933 ** * custom auxiliary functions.
11945 /*************************************************************************
11946 ** CUSTOM AUXILIARY FUNCTIONS
11948 ** Virtual table implementations may overload SQL functions by implementing
11949 ** the sqlite3_module.xFindFunction() method.
11952 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11953 typedef struct Fts5Context Fts5Context;
11954 typedef struct Fts5PhraseIter Fts5PhraseIter;
11956 typedef void (*fts5_extension_function)(
11957 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11958 Fts5Context *pFts, /* First arg to pass to pApi functions */
11959 sqlite3_context *pCtx, /* Context for returning result/error */
11960 int nVal, /* Number of values in apVal[] array */
11961 sqlite3_value **apVal /* Array of trailing arguments */
11964 struct Fts5PhraseIter {
11965 const unsigned char *a;
11966 const unsigned char *b;
11970 ** EXTENSION API FUNCTIONS
11972 ** xUserData(pFts):
11973 ** Return a copy of the context pointer the extension function was
11974 ** registered with.
11976 ** xColumnTotalSize(pFts, iCol, pnToken):
11977 ** If parameter iCol is less than zero, set output variable *pnToken
11978 ** to the total number of tokens in the FTS5 table. Or, if iCol is
11979 ** non-negative but less than the number of columns in the table, return
11980 ** the total number of tokens in column iCol, considering all rows in
11983 ** If parameter iCol is greater than or equal to the number of columns
11984 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11985 ** an OOM condition or IO error), an appropriate SQLite error code is
11988 ** xColumnCount(pFts):
11989 ** Return the number of columns in the table.
11991 ** xColumnSize(pFts, iCol, pnToken):
11992 ** If parameter iCol is less than zero, set output variable *pnToken
11993 ** to the total number of tokens in the current row. Or, if iCol is
11994 ** non-negative but less than the number of columns in the table, set
11995 ** *pnToken to the number of tokens in column iCol of the current row.
11997 ** If parameter iCol is greater than or equal to the number of columns
11998 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11999 ** an OOM condition or IO error), an appropriate SQLite error code is
12002 ** This function may be quite inefficient if used with an FTS5 table
12003 ** created with the "columnsize=0" option.
12006 ** This function attempts to retrieve the text of column iCol of the
12007 ** current document. If successful, (*pz) is set to point to a buffer
12008 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12009 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12010 ** if an error occurs, an SQLite error code is returned and the final values
12011 ** of (*pz) and (*pn) are undefined.
12014 ** Returns the number of phrases in the current query expression.
12017 ** Returns the number of tokens in phrase iPhrase of the query. Phrases
12018 ** are numbered starting from zero.
12021 ** Set *pnInst to the total number of occurrences of all phrases within
12022 ** the query within the current row. Return SQLITE_OK if successful, or
12023 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12025 ** This API can be quite slow if used with an FTS5 table created with the
12026 ** "detail=none" or "detail=column" option. If the FTS5 table is created
12027 ** with either "detail=none" or "detail=column" and "content=" option
12028 ** (i.e. if it is a contentless table), then this API always returns 0.
12031 ** Query for the details of phrase match iIdx within the current row.
12032 ** Phrase matches are numbered starting from zero, so the iIdx argument
12033 ** should be greater than or equal to zero and smaller than the value
12034 ** output by xInstCount().
12036 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12037 ** to the column in which it occurs and *piOff the token offset of the
12038 ** first token of the phrase. Returns SQLITE_OK if successful, or an error
12039 ** code (i.e. SQLITE_NOMEM) if an error occurs.
12041 ** This API can be quite slow if used with an FTS5 table created with the
12042 ** "detail=none" or "detail=column" option.
12045 ** Returns the rowid of the current row.
12048 ** Tokenize text using the tokenizer belonging to the FTS5 table.
12050 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12051 ** This API function is used to query the FTS table for phrase iPhrase
12052 ** of the current query. Specifically, a query equivalent to:
12054 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12056 ** with $p set to a phrase equivalent to the phrase iPhrase of the
12057 ** current query is executed. Any column filter that applies to
12058 ** phrase iPhrase of the current query is included in $p. For each
12059 ** row visited, the callback function passed as the fourth argument
12060 ** is invoked. The context and API objects passed to the callback
12061 ** function may be used to access the properties of each matched row.
12062 ** Invoking Api.xUserData() returns a copy of the pointer passed as
12063 ** the third argument to pUserData.
12065 ** If the callback function returns any value other than SQLITE_OK, the
12066 ** query is abandoned and the xQueryPhrase function returns immediately.
12067 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12068 ** Otherwise, the error code is propagated upwards.
12070 ** If the query runs to completion without incident, SQLITE_OK is returned.
12071 ** Or, if some error occurs before the query completes or is aborted by
12072 ** the callback, an SQLite error code is returned.
12075 ** xSetAuxdata(pFts5, pAux, xDelete)
12077 ** Save the pointer passed as the second argument as the extension function's
12078 ** "auxiliary data". The pointer may then be retrieved by the current or any
12079 ** future invocation of the same fts5 extension function made as part of
12080 ** the same MATCH query using the xGetAuxdata() API.
12082 ** Each extension function is allocated a single auxiliary data slot for
12083 ** each FTS query (MATCH expression). If the extension function is invoked
12084 ** more than once for a single FTS query, then all invocations share a
12085 ** single auxiliary data context.
12087 ** If there is already an auxiliary data pointer when this function is
12088 ** invoked, then it is replaced by the new pointer. If an xDelete callback
12089 ** was specified along with the original pointer, it is invoked at this
12092 ** The xDelete callback, if one is specified, is also invoked on the
12093 ** auxiliary data pointer after the FTS5 query has finished.
12095 ** If an error (e.g. an OOM condition) occurs within this function,
12096 ** the auxiliary data is set to NULL and an error code returned. If the
12097 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
12098 ** pointer before returning.
12101 ** xGetAuxdata(pFts5, bClear)
12103 ** Returns the current auxiliary data pointer for the fts5 extension
12104 ** function. See the xSetAuxdata() method for details.
12106 ** If the bClear argument is non-zero, then the auxiliary data is cleared
12107 ** (set to NULL) before this function returns. In this case the xDelete,
12108 ** if any, is not invoked.
12111 ** xRowCount(pFts5, pnRow)
12113 ** This function is used to retrieve the total number of rows in the table.
12114 ** In other words, the same value that would be returned by:
12116 ** SELECT count(*) FROM ftstable;
12119 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12120 ** method, to iterate through all instances of a single query phrase within
12121 ** the current row. This is the same information as is accessible via the
12122 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12123 ** to use, this API may be faster under some circumstances. To iterate
12124 ** through instances of phrase iPhrase, use the following code:
12126 ** Fts5PhraseIter iter;
12128 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12130 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12132 ** // An instance of phrase iPhrase at offset iOff of column iCol
12135 ** The Fts5PhraseIter structure is defined above. Applications should not
12136 ** modify this structure directly - it should only be used as shown above
12137 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
12138 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12140 ** This API can be quite slow if used with an FTS5 table created with the
12141 ** "detail=none" or "detail=column" option. If the FTS5 table is created
12142 ** with either "detail=none" or "detail=column" and "content=" option
12143 ** (i.e. if it is a contentless table), then this API always iterates
12144 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12147 ** See xPhraseFirst above.
12149 ** xPhraseFirstColumn()
12150 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12151 ** and xPhraseNext() APIs described above. The difference is that instead
12152 ** of iterating through all instances of a phrase in the current row, these
12153 ** APIs are used to iterate through the set of columns in the current row
12154 ** that contain one or more instances of a specified phrase. For example:
12156 ** Fts5PhraseIter iter;
12158 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12160 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12162 ** // Column iCol contains at least one instance of phrase iPhrase
12165 ** This API can be quite slow if used with an FTS5 table created with the
12166 ** "detail=none" option. If the FTS5 table is created with either
12167 ** "detail=none" "content=" option (i.e. if it is a contentless table),
12168 ** then this API always iterates through an empty set (all calls to
12169 ** xPhraseFirstColumn() set iCol to -1).
12171 ** The information accessed using this API and its companion
12172 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12173 ** (or xInst/xInstCount). The chief advantage of this API is that it is
12174 ** significantly more efficient than those alternatives when used with
12175 ** "detail=column" tables.
12177 ** xPhraseNextColumn()
12178 ** See xPhraseFirstColumn above.
12180 struct Fts5ExtensionApi {
12181 int iVersion; /* Currently always set to 3 */
12183 void *(*xUserData)(Fts5Context*);
12185 int (*xColumnCount)(Fts5Context*);
12186 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12187 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12189 int (*xTokenize)(Fts5Context*,
12190 const char *pText, int nText, /* Text to tokenize */
12191 void *pCtx, /* Context passed to xToken() */
12192 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12195 int (*xPhraseCount)(Fts5Context*);
12196 int (*xPhraseSize)(Fts5Context*, int iPhrase);
12198 int (*xInstCount)(Fts5Context*, int *pnInst);
12199 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12201 sqlite3_int64 (*xRowid)(Fts5Context*);
12202 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12203 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12205 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12206 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12208 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12209 void *(*xGetAuxdata)(Fts5Context*, int bClear);
12211 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12212 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12214 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12215 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12219 ** CUSTOM AUXILIARY FUNCTIONS
12220 *************************************************************************/
12222 /*************************************************************************
12223 ** CUSTOM TOKENIZERS
12225 ** Applications may also register custom tokenizer types. A tokenizer
12226 ** is registered by providing fts5 with a populated instance of the
12227 ** following structure. All structure methods must be defined, setting
12228 ** any member of the fts5_tokenizer struct to NULL leads to undefined
12229 ** behaviour. The structure methods are expected to function as follows:
12232 ** This function is used to allocate and initialize a tokenizer instance.
12233 ** A tokenizer instance is required to actually tokenize text.
12235 ** The first argument passed to this function is a copy of the (void*)
12236 ** pointer provided by the application when the fts5_tokenizer object
12237 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
12238 ** The second and third arguments are an array of nul-terminated strings
12239 ** containing the tokenizer arguments, if any, specified following the
12240 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12241 ** to create the FTS5 table.
12243 ** The final argument is an output variable. If successful, (*ppOut)
12244 ** should be set to point to the new tokenizer handle and SQLITE_OK
12245 ** returned. If an error occurs, some value other than SQLITE_OK should
12246 ** be returned. In this case, fts5 assumes that the final value of *ppOut
12250 ** This function is invoked to delete a tokenizer handle previously
12251 ** allocated using xCreate(). Fts5 guarantees that this function will
12252 ** be invoked exactly once for each successful call to xCreate().
12255 ** This function is expected to tokenize the nText byte string indicated
12256 ** by argument pText. pText may or may not be nul-terminated. The first
12257 ** argument passed to this function is a pointer to an Fts5Tokenizer object
12258 ** returned by an earlier call to xCreate().
12260 ** The second argument indicates the reason that FTS5 is requesting
12261 ** tokenization of the supplied text. This is always one of the following
12264 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12265 ** or removed from the FTS table. The tokenizer is being invoked to
12266 ** determine the set of tokens to add to (or delete from) the
12269 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12270 ** against the FTS index. The tokenizer is being called to tokenize
12271 ** a bareword or quoted string specified as part of the query.
12273 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12274 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12275 ** followed by a "*" character, indicating that the last token
12276 ** returned by the tokenizer will be treated as a token prefix.
12278 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12279 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
12280 ** function. Or an fts5_api.xColumnSize() request made by the same
12281 ** on a columnsize=0 database.
12284 ** For each token in the input string, the supplied callback xToken() must
12285 ** be invoked. The first argument to it should be a copy of the pointer
12286 ** passed as the second argument to xTokenize(). The third and fourth
12287 ** arguments are a pointer to a buffer containing the token text, and the
12288 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12289 ** of the first byte of and first byte immediately following the text from
12290 ** which the token is derived within the input.
12292 ** The second argument passed to the xToken() callback ("tflags") should
12293 ** normally be set to 0. The exception is if the tokenizer supports
12294 ** synonyms. In this case see the discussion below for details.
12296 ** FTS5 assumes the xToken() callback is invoked for each token in the
12297 ** order that they occur within the input text.
12299 ** If an xToken() callback returns any value other than SQLITE_OK, then
12300 ** the tokenization should be abandoned and the xTokenize() method should
12301 ** immediately return a copy of the xToken() return value. Or, if the
12302 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12303 ** if an error occurs with the xTokenize() implementation itself, it
12304 ** may abandon the tokenization and return any error code other than
12305 ** SQLITE_OK or SQLITE_DONE.
12309 ** Custom tokenizers may also support synonyms. Consider a case in which a
12310 ** user wishes to query for a phrase such as "first place". Using the
12311 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
12312 ** of "first place" within the document set, but not alternative forms
12313 ** such as "1st place". In some applications, it would be better to match
12314 ** all instances of "first place" or "1st place" regardless of which form
12315 ** the user specified in the MATCH query text.
12317 ** There are several ways to approach this in FTS5:
12319 ** <ol><li> By mapping all synonyms to a single token. In this case, using
12320 ** the above example, this means that the tokenizer returns the
12321 ** same token for inputs "first" and "1st". Say that token is in
12322 ** fact "first", so that when the user inserts the document "I won
12323 ** 1st place" entries are added to the index for tokens "i", "won",
12324 ** "first" and "place". If the user then queries for '1st + place',
12325 ** the tokenizer substitutes "first" for "1st" and the query works
12328 ** <li> By querying the index for all synonyms of each query term
12329 ** separately. In this case, when tokenizing query text, the
12330 ** tokenizer may provide multiple synonyms for a single term
12331 ** within the document. FTS5 then queries the index for each
12332 ** synonym individually. For example, faced with the query:
12335 ** ... MATCH 'first place'</codeblock>
12337 ** the tokenizer offers both "1st" and "first" as synonyms for the
12338 ** first token in the MATCH query and FTS5 effectively runs a query
12342 ** ... MATCH '(first OR 1st) place'</codeblock>
12344 ** except that, for the purposes of auxiliary functions, the query
12345 ** still appears to contain just two phrases - "(first OR 1st)"
12346 ** being treated as a single phrase.
12348 ** <li> By adding multiple synonyms for a single term to the FTS index.
12349 ** Using this method, when tokenizing document text, the tokenizer
12350 ** provides multiple synonyms for each token. So that when a
12351 ** document such as "I won first place" is tokenized, entries are
12352 ** added to the FTS index for "i", "won", "first", "1st" and
12355 ** This way, even if the tokenizer does not provide synonyms
12356 ** when tokenizing query text (it should not - to do so would be
12357 ** inefficient), it doesn't matter if the user queries for
12358 ** 'first + place' or '1st + place', as there are entries in the
12359 ** FTS index corresponding to both forms of the first token.
12362 ** Whether it is parsing document or query text, any call to xToken that
12363 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12364 ** is considered to supply a synonym for the previous token. For example,
12365 ** when parsing the document "I won first place", a tokenizer that supports
12366 ** synonyms would call xToken() 5 times, as follows:
12369 ** xToken(pCtx, 0, "i", 1, 0, 1);
12370 ** xToken(pCtx, 0, "won", 3, 2, 5);
12371 ** xToken(pCtx, 0, "first", 5, 6, 11);
12372 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12373 ** xToken(pCtx, 0, "place", 5, 12, 17);
12376 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12377 ** xToken() is called. Multiple synonyms may be specified for a single token
12378 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12379 ** There is no limit to the number of synonyms that may be provided for a
12382 ** In many cases, method (1) above is the best approach. It does not add
12383 ** extra data to the FTS index or require FTS5 to query for multiple terms,
12384 ** so it is efficient in terms of disk space and query speed. However, it
12385 ** does not support prefix queries very well. If, as suggested above, the
12386 ** token "first" is substituted for "1st" by the tokenizer, then the query:
12389 ** ... MATCH '1s*'</codeblock>
12391 ** will not match documents that contain the token "1st" (as the tokenizer
12392 ** will probably not map "1s" to any prefix of "first").
12394 ** For full prefix support, method (3) may be preferred. In this case,
12395 ** because the index contains entries for both "first" and "1st", prefix
12396 ** queries such as 'fi*' or '1s*' will match correctly. However, because
12397 ** extra entries are added to the FTS index, this method uses more space
12398 ** within the database.
12400 ** Method (2) offers a midpoint between (1) and (3). Using this method,
12401 ** a query such as '1s*' will match documents that contain the literal
12402 ** token "1st", but not "first" (assuming the tokenizer is not able to
12403 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
12404 ** will match against "1st" and "first". This method does not require
12405 ** extra disk space, as no extra entries are added to the FTS index.
12406 ** On the other hand, it may require more CPU cycles to run MATCH queries,
12407 ** as separate queries of the FTS index are required for each synonym.
12409 ** When using methods (2) or (3), it is important that the tokenizer only
12410 ** provide synonyms when tokenizing document text (method (2)) or query
12411 ** text (method (3)), not both. Doing so will not cause any errors, but is
12414 typedef struct Fts5Tokenizer Fts5Tokenizer;
12415 typedef struct fts5_tokenizer fts5_tokenizer;
12416 struct fts5_tokenizer {
12417 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12418 void (*xDelete)(Fts5Tokenizer*);
12419 int (*xTokenize)(Fts5Tokenizer*,
12421 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12422 const char *pText, int nText,
12424 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12425 int tflags, /* Mask of FTS5_TOKEN_* flags */
12426 const char *pToken, /* Pointer to buffer containing token */
12427 int nToken, /* Size of token in bytes */
12428 int iStart, /* Byte offset of token within input text */
12429 int iEnd /* Byte offset of end of token within input text */
12434 /* Flags that may be passed as the third argument to xTokenize() */
12435 #define FTS5_TOKENIZE_QUERY 0x0001
12436 #define FTS5_TOKENIZE_PREFIX 0x0002
12437 #define FTS5_TOKENIZE_DOCUMENT 0x0004
12438 #define FTS5_TOKENIZE_AUX 0x0008
12440 /* Flags that may be passed by the tokenizer implementation back to FTS5
12441 ** as the third argument to the supplied xToken callback. */
12442 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12445 ** END OF CUSTOM TOKENIZERS
12446 *************************************************************************/
12448 /*************************************************************************
12449 ** FTS5 EXTENSION REGISTRATION API
12451 typedef struct fts5_api fts5_api;
12453 int iVersion; /* Currently always set to 2 */
12455 /* Create a new tokenizer */
12456 int (*xCreateTokenizer)(
12460 fts5_tokenizer *pTokenizer,
12461 void (*xDestroy)(void*)
12464 /* Find an existing tokenizer */
12465 int (*xFindTokenizer)(
12469 fts5_tokenizer *pTokenizer
12472 /* Create a new auxiliary function */
12473 int (*xCreateFunction)(
12477 fts5_extension_function xFunction,
12478 void (*xDestroy)(void*)
12483 ** END OF REGISTRATION API
12484 *************************************************************************/
12487 } /* end of the 'extern "C"' block */
12490 #endif /* _FTS5_H */
12492 /******** End of fts5.h *********/