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 ** Provide the ability to override linkage features of the interface.
49 # define SQLITE_EXTERN extern
57 #ifndef SQLITE_APICALL
58 # define SQLITE_APICALL
60 #ifndef SQLITE_STDCALL
61 # define SQLITE_STDCALL SQLITE_APICALL
63 #ifndef SQLITE_CALLBACK
64 # define SQLITE_CALLBACK
67 # define SQLITE_SYSAPI
71 ** These no-op macros are used in front of interfaces to mark those
72 ** interfaces as either deprecated or experimental. New applications
73 ** should not use deprecated interfaces - they are supported for backwards
74 ** compatibility only. Application writers should be aware that
75 ** experimental interfaces are subject to change in point releases.
77 ** These macros used to resolve to various kinds of compiler magic that
78 ** would generate warning messages when they were used. But that
79 ** compiler magic ended up generating such a flurry of bug reports
80 ** that we have taken it all out and gone back to using simple
83 #define SQLITE_DEPRECATED
84 #define SQLITE_EXPERIMENTAL
87 ** Ensure these symbols were not defined by some previous header file.
90 # undef SQLITE_VERSION
92 #ifdef SQLITE_VERSION_NUMBER
93 # undef SQLITE_VERSION_NUMBER
97 ** CAPI3REF: Compile-Time Library Version Numbers
99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100 ** evaluates to a string literal that is the SQLite version in the
101 ** format "X.Y.Z" where X is the major version number (always 3 for
102 ** SQLite3) and Y is the minor version number and Z is the release number.)^
103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105 ** numbers used in [SQLITE_VERSION].)^
106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107 ** be larger than the release from which it is derived. Either Y will
108 ** be held constant and Z will be incremented or else Y will be incremented
109 ** and Z will be reset to zero.
111 ** Since [version 3.6.18] ([dateof:3.6.18]),
112 ** SQLite source code has been stored in the
113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115 ** a string which identifies a particular check-in of SQLite
116 ** within its configuration management system. ^The SQLITE_SOURCE_ID
117 ** string contains the date and time of the check-in (UTC) and a SHA1
118 ** or SHA3-256 hash of the entire source tree.
120 ** See also: [sqlite3_libversion()],
121 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
122 ** [sqlite_version()] and [sqlite_source_id()].
124 #define SQLITE_VERSION "3.19.3"
125 #define SQLITE_VERSION_NUMBER 3019003
126 #define SQLITE_SOURCE_ID "2017-06-08 14:26:16 0ee482a1e0eae22e08edc8978c9733a96603d4509645f348ebf55b579e89636b"
129 ** CAPI3REF: Run-Time Library Version Numbers
130 ** KEYWORDS: sqlite3_version sqlite3_sourceid
132 ** These interfaces provide the same information as the [SQLITE_VERSION],
133 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
134 ** but are associated with the library instead of the header file. ^(Cautious
135 ** programmers might include assert() statements in their application to
136 ** verify that values returned by these interfaces match the macros in
137 ** the header, and thus ensure that the application is
138 ** compiled with matching library and header files.
141 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
142 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
143 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
144 ** </pre></blockquote>)^
146 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
147 ** macro. ^The sqlite3_libversion() function returns a pointer to the
148 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
149 ** function is provided for use in DLLs since DLL users usually do not have
150 ** direct access to string constants within the DLL. ^The
151 ** sqlite3_libversion_number() function returns an integer equal to
152 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
153 ** a pointer to a string constant whose value is the same as the
154 ** [SQLITE_SOURCE_ID] C preprocessor macro.
156 ** See also: [sqlite_version()] and [sqlite_source_id()].
158 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
159 SQLITE_API const char *sqlite3_libversion(void);
160 SQLITE_API const char *sqlite3_sourceid(void);
161 SQLITE_API int sqlite3_libversion_number(void);
164 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
166 ** ^The sqlite3_compileoption_used() function returns 0 or 1
167 ** indicating whether the specified option was defined at
168 ** compile time. ^The SQLITE_ prefix may be omitted from the
169 ** option name passed to sqlite3_compileoption_used().
171 ** ^The sqlite3_compileoption_get() function allows iterating
172 ** over the list of options that were defined at compile time by
173 ** returning the N-th compile time option string. ^If N is out of range,
174 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
175 ** prefix is omitted from any strings returned by
176 ** sqlite3_compileoption_get().
178 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
179 ** and sqlite3_compileoption_get() may be omitted by specifying the
180 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
182 ** See also: SQL functions [sqlite_compileoption_used()] and
183 ** [sqlite_compileoption_get()] and the [compile_options pragma].
185 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
186 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
187 SQLITE_API const char *sqlite3_compileoption_get(int N);
191 ** CAPI3REF: Test To See If The Library Is Threadsafe
193 ** ^The sqlite3_threadsafe() function returns zero if and only if
194 ** SQLite was compiled with mutexing code omitted due to the
195 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
197 ** SQLite can be compiled with or without mutexes. When
198 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
199 ** are enabled and SQLite is threadsafe. When the
200 ** [SQLITE_THREADSAFE] macro is 0,
201 ** the mutexes are omitted. Without the mutexes, it is not safe
202 ** to use SQLite concurrently from more than one thread.
204 ** Enabling mutexes incurs a measurable performance penalty.
205 ** So if speed is of utmost importance, it makes sense to disable
206 ** the mutexes. But for maximum safety, mutexes should be enabled.
207 ** ^The default behavior is for mutexes to be enabled.
209 ** This interface can be used by an application to make sure that the
210 ** version of SQLite that it is linking against was compiled with
211 ** the desired setting of the [SQLITE_THREADSAFE] macro.
213 ** This interface only reports on the compile-time mutex setting
214 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
215 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
216 ** can be fully or partially disabled using a call to [sqlite3_config()]
217 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
218 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
219 ** sqlite3_threadsafe() function shows only the compile-time setting of
220 ** thread safety, not any run-time changes to that setting made by
221 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
222 ** is unchanged by calls to sqlite3_config().)^
224 ** See the [threading mode] documentation for additional information.
226 SQLITE_API int sqlite3_threadsafe(void);
229 ** CAPI3REF: Database Connection Handle
230 ** KEYWORDS: {database connection} {database connections}
232 ** Each open SQLite database is represented by a pointer to an instance of
233 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
234 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
235 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
236 ** and [sqlite3_close_v2()] are its destructors. There are many other
237 ** interfaces (such as
238 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
239 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
242 typedef struct sqlite3 sqlite3;
245 ** CAPI3REF: 64-Bit Integer Types
246 ** KEYWORDS: sqlite_int64 sqlite_uint64
248 ** Because there is no cross-platform way to specify 64-bit integer types
249 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
251 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
252 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
253 ** compatibility only.
255 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
256 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
257 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
258 ** between 0 and +18446744073709551615 inclusive.
260 #ifdef SQLITE_INT64_TYPE
261 typedef SQLITE_INT64_TYPE sqlite_int64;
262 # ifdef SQLITE_UINT64_TYPE
263 typedef SQLITE_UINT64_TYPE sqlite_uint64;
265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
267 #elif defined(_MSC_VER) || defined(__BORLANDC__)
268 typedef __int64 sqlite_int64;
269 typedef unsigned __int64 sqlite_uint64;
271 typedef long long int sqlite_int64;
272 typedef unsigned long long int sqlite_uint64;
274 typedef sqlite_int64 sqlite3_int64;
275 typedef sqlite_uint64 sqlite3_uint64;
278 ** If compiling for a processor that lacks floating point support,
279 ** substitute integer for floating-point.
281 #ifdef SQLITE_OMIT_FLOATING_POINT
282 # define double sqlite3_int64
286 ** CAPI3REF: Closing A Database Connection
287 ** DESTRUCTOR: sqlite3
289 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
290 ** for the [sqlite3] object.
291 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
292 ** the [sqlite3] object is successfully destroyed and all associated
293 ** resources are deallocated.
295 ** ^If the database connection is associated with unfinalized prepared
296 ** statements or unfinished sqlite3_backup objects then sqlite3_close()
297 ** will leave the database connection open and return [SQLITE_BUSY].
298 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
299 ** and/or unfinished sqlite3_backups, then the database connection becomes
300 ** an unusable "zombie" which will automatically be deallocated when the
301 ** last prepared statement is finalized or the last sqlite3_backup is
302 ** finished. The sqlite3_close_v2() interface is intended for use with
303 ** host languages that are garbage collected, and where the order in which
304 ** destructors are called is arbitrary.
306 ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
307 ** [sqlite3_blob_close | close] all [BLOB handles], and
308 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
309 ** with the [sqlite3] object prior to attempting to close the object. ^If
310 ** sqlite3_close_v2() is called on a [database connection] that still has
311 ** outstanding [prepared statements], [BLOB handles], and/or
312 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
313 ** of resources is deferred until all [prepared statements], [BLOB handles],
314 ** and [sqlite3_backup] objects are also destroyed.
316 ** ^If an [sqlite3] object is destroyed while a transaction is open,
317 ** the transaction is automatically rolled back.
319 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
320 ** must be either a NULL
321 ** pointer or an [sqlite3] object pointer obtained
322 ** from [sqlite3_open()], [sqlite3_open16()], or
323 ** [sqlite3_open_v2()], and not previously closed.
324 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
325 ** argument is a harmless no-op.
327 SQLITE_API int sqlite3_close(sqlite3*);
328 SQLITE_API int sqlite3_close_v2(sqlite3*);
331 ** The type for a callback function.
332 ** This is legacy and deprecated. It is included for historical
333 ** compatibility and is not documented.
335 typedef int (*sqlite3_callback)(void*,int,char**, char**);
338 ** CAPI3REF: One-Step Query Execution Interface
341 ** The sqlite3_exec() interface is a convenience wrapper around
342 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
343 ** that allows an application to run multiple statements of SQL
344 ** without having to use a lot of C code.
346 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
347 ** semicolon-separate SQL statements passed into its 2nd argument,
348 ** in the context of the [database connection] passed in as its 1st
349 ** argument. ^If the callback function of the 3rd argument to
350 ** sqlite3_exec() is not NULL, then it is invoked for each result row
351 ** coming out of the evaluated SQL statements. ^The 4th argument to
352 ** sqlite3_exec() is relayed through to the 1st argument of each
353 ** callback invocation. ^If the callback pointer to sqlite3_exec()
354 ** is NULL, then no callback is ever invoked and result rows are
357 ** ^If an error occurs while evaluating the SQL statements passed into
358 ** sqlite3_exec(), then execution of the current statement stops and
359 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
360 ** is not NULL then any error message is written into memory obtained
361 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
362 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
363 ** on error message strings returned through the 5th parameter of
364 ** sqlite3_exec() after the error message string is no longer needed.
365 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
366 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
367 ** NULL before returning.
369 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
370 ** routine returns SQLITE_ABORT without invoking the callback again and
371 ** without running any subsequent SQL statements.
373 ** ^The 2nd argument to the sqlite3_exec() callback function is the
374 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
375 ** callback is an array of pointers to strings obtained as if from
376 ** [sqlite3_column_text()], one for each column. ^If an element of a
377 ** result row is NULL then the corresponding string pointer for the
378 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
379 ** sqlite3_exec() callback is an array of pointers to strings where each
380 ** entry represents the name of corresponding result column as obtained
381 ** from [sqlite3_column_name()].
383 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
384 ** to an empty string, or a pointer that contains only whitespace and/or
385 ** SQL comments, then no SQL statements are evaluated and the database
391 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
392 ** is a valid and open [database connection].
393 ** <li> The application must not close the [database connection] specified by
394 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
395 ** <li> The application must not modify the SQL statement text passed into
396 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
399 SQLITE_API int sqlite3_exec(
400 sqlite3*, /* An open database */
401 const char *sql, /* SQL to be evaluated */
402 int (*callback)(void*,int,char**,char**), /* Callback function */
403 void *, /* 1st argument to callback */
404 char **errmsg /* Error msg written here */
408 ** CAPI3REF: Result Codes
409 ** KEYWORDS: {result code definitions}
411 ** Many SQLite functions return an integer result code from the set shown
412 ** here in order to indicate success or failure.
414 ** New error codes may be added in future versions of SQLite.
416 ** See also: [extended result code definitions]
418 #define SQLITE_OK 0 /* Successful result */
419 /* beginning-of-error-codes */
420 #define SQLITE_ERROR 1 /* SQL error or missing database */
421 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
422 #define SQLITE_PERM 3 /* Access permission denied */
423 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
424 #define SQLITE_BUSY 5 /* The database file is locked */
425 #define SQLITE_LOCKED 6 /* A table in the database is locked */
426 #define SQLITE_NOMEM 7 /* A malloc() failed */
427 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
428 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
429 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
430 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
431 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
432 #define SQLITE_FULL 13 /* Insertion failed because database is full */
433 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
434 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
435 #define SQLITE_EMPTY 16 /* Database is empty */
436 #define SQLITE_SCHEMA 17 /* The database schema changed */
437 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
438 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
439 #define SQLITE_MISMATCH 20 /* Data type mismatch */
440 #define SQLITE_MISUSE 21 /* Library used incorrectly */
441 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
442 #define SQLITE_AUTH 23 /* Authorization denied */
443 #define SQLITE_FORMAT 24 /* Auxiliary database format error */
444 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
445 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
446 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
447 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
448 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
449 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
450 /* end-of-error-codes */
453 ** CAPI3REF: Extended Result Codes
454 ** KEYWORDS: {extended result code definitions}
456 ** In its default configuration, SQLite API routines return one of 30 integer
457 ** [result codes]. However, experience has shown that many of
458 ** these result codes are too coarse-grained. They do not provide as
459 ** much information about problems as programmers might like. In an effort to
460 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
461 ** and later) include
462 ** support for additional result codes that provide more detailed information
463 ** about errors. These [extended result codes] are enabled or disabled
464 ** on a per database connection basis using the
465 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
466 ** the most recent error can be obtained using
467 ** [sqlite3_extended_errcode()].
469 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
470 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
471 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
472 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
473 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
474 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
475 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
476 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
477 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
478 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
479 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
480 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
481 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
482 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
483 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
484 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
485 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
486 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
487 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
488 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
489 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
490 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
491 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
492 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
493 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
494 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
495 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
496 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
497 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
498 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
499 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
500 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
501 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
502 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
503 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
504 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
505 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
506 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
507 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
508 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
509 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
510 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
511 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
512 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
513 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
514 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
515 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
516 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
517 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
518 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
519 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
520 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
521 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
522 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
523 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
524 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
527 ** CAPI3REF: Flags For File Open Operations
529 ** These bit values are intended for use in the
530 ** 3rd parameter to the [sqlite3_open_v2()] interface and
531 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
533 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
534 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
535 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
536 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
537 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
538 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
539 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
540 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
541 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
542 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
543 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
544 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
545 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
546 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
547 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
548 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
549 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
550 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
551 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
552 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
554 /* Reserved: 0x00F00000 */
557 ** CAPI3REF: Device Characteristics
559 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
560 ** object returns an integer which is a vector of these
561 ** bit values expressing I/O characteristics of the mass storage
562 ** device that holds the file that the [sqlite3_io_methods]
565 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
566 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
567 ** mean that writes of blocks that are nnn bytes in size and
568 ** are aligned to an address which is an integer multiple of
569 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
570 ** that when data is appended to a file, the data is appended
571 ** first then the size of the file is extended, never the other
572 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
573 ** information is written to disk in the same order as calls
574 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
575 ** after reboot following a crash or power loss, the only bytes in a
576 ** file that were written at the application level might have changed
577 ** and that adjacent bytes, even bytes within the same sector are
578 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
579 ** flag indicates that a file cannot be deleted when open. The
580 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
581 ** read-only media and cannot be changed even by processes with
582 ** elevated privileges.
584 #define SQLITE_IOCAP_ATOMIC 0x00000001
585 #define SQLITE_IOCAP_ATOMIC512 0x00000002
586 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
587 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
588 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
589 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
590 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
591 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
592 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
593 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
594 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
595 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
596 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
597 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
600 ** CAPI3REF: File Locking Levels
602 ** SQLite uses one of these integer values as the second
603 ** argument to calls it makes to the xLock() and xUnlock() methods
604 ** of an [sqlite3_io_methods] object.
606 #define SQLITE_LOCK_NONE 0
607 #define SQLITE_LOCK_SHARED 1
608 #define SQLITE_LOCK_RESERVED 2
609 #define SQLITE_LOCK_PENDING 3
610 #define SQLITE_LOCK_EXCLUSIVE 4
613 ** CAPI3REF: Synchronization Type Flags
615 ** When SQLite invokes the xSync() method of an
616 ** [sqlite3_io_methods] object it uses a combination of
617 ** these integer values as the second argument.
619 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
620 ** sync operation only needs to flush data to mass storage. Inode
621 ** information need not be flushed. If the lower four bits of the flag
622 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
623 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
624 ** to use Mac OS X style fullsync instead of fsync().
626 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
627 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
628 ** settings. The [synchronous pragma] determines when calls to the
629 ** xSync VFS method occur and applies uniformly across all platforms.
630 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
631 ** energetic or rigorous or forceful the sync operations are and
632 ** only make a difference on Mac OSX for the default SQLite code.
633 ** (Third-party VFS implementations might also make the distinction
634 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
635 ** operating systems natively supported by SQLite, only Mac OSX
636 ** cares about the difference.)
638 #define SQLITE_SYNC_NORMAL 0x00002
639 #define SQLITE_SYNC_FULL 0x00003
640 #define SQLITE_SYNC_DATAONLY 0x00010
643 ** CAPI3REF: OS Interface Open File Handle
645 ** An [sqlite3_file] object represents an open file in the
646 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
647 ** implementations will
648 ** want to subclass this object by appending additional fields
649 ** for their own use. The pMethods entry is a pointer to an
650 ** [sqlite3_io_methods] object that defines methods for performing
651 ** I/O operations on the open file.
653 typedef struct sqlite3_file sqlite3_file;
654 struct sqlite3_file {
655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
659 ** CAPI3REF: OS Interface File Virtual Methods Object
661 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
662 ** [sqlite3_file] object (or, more commonly, a subclass of the
663 ** [sqlite3_file] object) with a pointer to an instance of this object.
664 ** This object defines the methods used to perform various operations
665 ** against the open file represented by the [sqlite3_file] object.
667 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
668 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
669 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
670 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
671 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
674 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
675 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
676 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
677 ** flag may be ORed in to indicate that only the data of the file
678 ** and not its inode needs to be synced.
680 ** The integer values to xLock() and xUnlock() are one of
682 ** <li> [SQLITE_LOCK_NONE],
683 ** <li> [SQLITE_LOCK_SHARED],
684 ** <li> [SQLITE_LOCK_RESERVED],
685 ** <li> [SQLITE_LOCK_PENDING], or
686 ** <li> [SQLITE_LOCK_EXCLUSIVE].
688 ** xLock() increases the lock. xUnlock() decreases the lock.
689 ** The xCheckReservedLock() method checks whether any database connection,
690 ** either in this process or in some other process, is holding a RESERVED,
691 ** PENDING, or EXCLUSIVE lock on the file. It returns true
692 ** if such a lock exists and false otherwise.
694 ** The xFileControl() method is a generic interface that allows custom
695 ** VFS implementations to directly control an open file using the
696 ** [sqlite3_file_control()] interface. The second "op" argument is an
697 ** integer opcode. The third argument is a generic pointer intended to
698 ** point to a structure that may contain arguments or space in which to
699 ** write return values. Potential uses for xFileControl() might be
700 ** functions to enable blocking locks with timeouts, to change the
701 ** locking strategy (for example to use dot-file locks), to inquire
702 ** about the status of a lock, or to break stale locks. The SQLite
703 ** core reserves all opcodes less than 100 for its own use.
704 ** A [file control opcodes | list of opcodes] less than 100 is available.
705 ** Applications that define a custom xFileControl method should use opcodes
706 ** greater than 100 to avoid conflicts. VFS implementations should
707 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
710 ** The xSectorSize() method returns the sector size of the
711 ** device that underlies the file. The sector size is the
712 ** minimum write that can be performed without disturbing
713 ** other bytes in the file. The xDeviceCharacteristics()
714 ** method returns a bit vector describing behaviors of the
715 ** underlying device:
718 ** <li> [SQLITE_IOCAP_ATOMIC]
719 ** <li> [SQLITE_IOCAP_ATOMIC512]
720 ** <li> [SQLITE_IOCAP_ATOMIC1K]
721 ** <li> [SQLITE_IOCAP_ATOMIC2K]
722 ** <li> [SQLITE_IOCAP_ATOMIC4K]
723 ** <li> [SQLITE_IOCAP_ATOMIC8K]
724 ** <li> [SQLITE_IOCAP_ATOMIC16K]
725 ** <li> [SQLITE_IOCAP_ATOMIC32K]
726 ** <li> [SQLITE_IOCAP_ATOMIC64K]
727 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
728 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
729 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
730 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
731 ** <li> [SQLITE_IOCAP_IMMUTABLE]
734 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
735 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
736 ** mean that writes of blocks that are nnn bytes in size and
737 ** are aligned to an address which is an integer multiple of
738 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
739 ** that when data is appended to a file, the data is appended
740 ** first then the size of the file is extended, never the other
741 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
742 ** information is written to disk in the same order as calls
745 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
746 ** in the unread portions of the buffer with zeros. A VFS that
747 ** fails to zero-fill short reads might seem to work. However,
748 ** failure to zero-fill short reads will eventually lead to
749 ** database corruption.
751 typedef struct sqlite3_io_methods sqlite3_io_methods;
752 struct sqlite3_io_methods {
754 int (*xClose)(sqlite3_file*);
755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
758 int (*xSync)(sqlite3_file*, int flags);
759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
760 int (*xLock)(sqlite3_file*, int);
761 int (*xUnlock)(sqlite3_file*, int);
762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
763 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
764 int (*xSectorSize)(sqlite3_file*);
765 int (*xDeviceCharacteristics)(sqlite3_file*);
766 /* Methods above are valid for version 1 */
767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
769 void (*xShmBarrier)(sqlite3_file*);
770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
771 /* Methods above are valid for version 2 */
772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
774 /* Methods above are valid for version 3 */
775 /* Additional methods may be added in future releases */
779 ** CAPI3REF: Standard File Control Opcodes
780 ** KEYWORDS: {file control opcodes} {file control opcode}
782 ** These integer constants are opcodes for the xFileControl method
783 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
787 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
788 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
789 ** opcode causes the xFileControl method to write the current state of
790 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
791 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
792 ** into an integer that the pArg argument points to. This capability
793 ** is used during testing and is only available when the SQLITE_TEST
794 ** compile-time option is used.
796 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
797 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
798 ** layer a hint of how large the database file will grow to be during the
799 ** current transaction. This hint is not guaranteed to be accurate but it
800 ** is often close. The underlying VFS might choose to preallocate database
801 ** file space based on this hint in order to help writes to the database
804 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
805 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
806 ** extends and truncates the database file in chunks of a size specified
807 ** by the user. The fourth argument to [sqlite3_file_control()] should
808 ** point to an integer (type int) containing the new chunk-size to use
809 ** for the nominated database. Allocating database file space in large
810 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
811 ** improve performance on some systems.
813 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
814 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
815 ** to the [sqlite3_file] object associated with a particular database
816 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
818 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
819 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
820 ** to the [sqlite3_file] object associated with the journal file (either
821 ** the [rollback journal] or the [write-ahead log]) for a particular database
822 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
824 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
827 ** <li>[[SQLITE_FCNTL_SYNC]]
828 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
829 ** sent to the VFS immediately before the xSync method is invoked on a
830 ** database file descriptor. Or, if the xSync method is not invoked
831 ** because the user has configured SQLite with
832 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
833 ** of the xSync method. In most cases, the pointer argument passed with
834 ** this file-control is NULL. However, if the database file is being synced
835 ** as part of a multi-database commit, the argument points to a nul-terminated
836 ** string containing the transactions master-journal file name. VFSes that
837 ** do not need this signal should silently ignore this opcode. Applications
838 ** should not call [sqlite3_file_control()] with this opcode as doing so may
839 ** disrupt the operation of the specialized VFSes that do require it.
841 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
842 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
843 ** and sent to the VFS after a transaction has been committed immediately
844 ** but before the database is unlocked. VFSes that do not need this signal
845 ** should silently ignore this opcode. Applications should not call
846 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
847 ** operation of the specialized VFSes that do require it.
849 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
850 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
851 ** retry counts and intervals for certain disk I/O operations for the
852 ** windows [VFS] in order to provide robustness in the presence of
853 ** anti-virus programs. By default, the windows VFS will retry file read,
854 ** file write, and file delete operations up to 10 times, with a delay
855 ** of 25 milliseconds before the first retry and with the delay increasing
856 ** by an additional 25 milliseconds with each subsequent retry. This
857 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
858 ** to be adjusted. The values are changed for all database connections
859 ** within the same process. The argument is a pointer to an array of two
860 ** integers where the first integer is the new retry count and the second
861 ** integer is the delay. If either integer is negative, then the setting
862 ** is not changed but instead the prior value of that setting is written
863 ** into the array entry, allowing the current retry settings to be
864 ** interrogated. The zDbName parameter is ignored.
866 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
867 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
868 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
869 ** write ahead log and shared memory files used for transaction control
870 ** are automatically deleted when the latest connection to the database
871 ** closes. Setting persistent WAL mode causes those files to persist after
872 ** close. Persisting the files is useful when other processes that do not
873 ** have write permission on the directory containing the database file want
874 ** to read the database file, as the WAL and shared memory files must exist
875 ** in order for the database to be readable. The fourth parameter to
876 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
877 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
878 ** WAL mode. If the integer is -1, then it is overwritten with the current
879 ** WAL persistence setting.
881 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
882 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
883 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
884 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
885 ** xDeviceCharacteristics methods. The fourth parameter to
886 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
887 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
888 ** mode. If the integer is -1, then it is overwritten with the current
889 ** zero-damage mode setting.
891 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
892 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
893 ** a write transaction to indicate that, unless it is rolled back for some
894 ** reason, the entire database file will be overwritten by the current
895 ** transaction. This is used by VACUUM operations.
897 ** <li>[[SQLITE_FCNTL_VFSNAME]]
898 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
899 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
900 ** final bottom-level VFS are written into memory obtained from
901 ** [sqlite3_malloc()] and the result is stored in the char* variable
902 ** that the fourth parameter of [sqlite3_file_control()] points to.
903 ** The caller is responsible for freeing the memory when done. As with
904 ** all file-control actions, there is no guarantee that this will actually
905 ** do anything. Callers should initialize the char* variable to a NULL
906 ** pointer in case this file-control is not implemented. This file-control
907 ** is intended for diagnostic use only.
909 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
910 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
911 ** [VFSes] currently in use. ^(The argument X in
912 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
913 ** of type "[sqlite3_vfs] **". This opcodes will set *X
914 ** to a pointer to the top-level VFS.)^
915 ** ^When there are multiple VFS shims in the stack, this opcode finds the
916 ** upper-most shim only.
918 ** <li>[[SQLITE_FCNTL_PRAGMA]]
919 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
920 ** file control is sent to the open [sqlite3_file] object corresponding
921 ** to the database file to which the pragma statement refers. ^The argument
922 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
923 ** pointers to strings (char**) in which the second element of the array
924 ** is the name of the pragma and the third element is the argument to the
925 ** pragma or NULL if the pragma has no argument. ^The handler for an
926 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
927 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
928 ** or the equivalent and that string will become the result of the pragma or
929 ** the error message if the pragma fails. ^If the
930 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
931 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
932 ** file control returns [SQLITE_OK], then the parser assumes that the
933 ** VFS has handled the PRAGMA itself and the parser generates a no-op
934 ** prepared statement if result string is NULL, or that returns a copy
935 ** of the result string if the string is non-NULL.
936 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
937 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
938 ** that the VFS encountered an error while handling the [PRAGMA] and the
939 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
940 ** file control occurs at the beginning of pragma statement analysis and so
941 ** it is able to override built-in [PRAGMA] statements.
943 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
944 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
945 ** file-control may be invoked by SQLite on the database file handle
946 ** shortly after it is opened in order to provide a custom VFS with access
947 ** to the connections busy-handler callback. The argument is of type (void **)
948 ** - an array of two (void *) values. The first (void *) actually points
949 ** to a function of type (int (*)(void *)). In order to invoke the connections
950 ** busy-handler, this function should be invoked with the second (void *) in
951 ** the array as the only argument. If it returns non-zero, then the operation
952 ** should be retried. If it returns zero, the custom VFS should abandon the
953 ** current operation.
955 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
956 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
957 ** to have SQLite generate a
958 ** temporary filename using the same algorithm that is followed to generate
959 ** temporary filenames for TEMP tables and other internal uses. The
960 ** argument should be a char** which will be filled with the filename
961 ** written into memory obtained from [sqlite3_malloc()]. The caller should
962 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
964 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
965 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
966 ** maximum number of bytes that will be used for memory-mapped I/O.
967 ** The argument is a pointer to a value of type sqlite3_int64 that
968 ** is an advisory maximum number of bytes in the file to memory map. The
969 ** pointer is overwritten with the old value. The limit is not changed if
970 ** the value originally pointed to is negative, and so the current limit
971 ** can be queried by passing in a pointer to a negative number. This
972 ** file-control is used internally to implement [PRAGMA mmap_size].
974 ** <li>[[SQLITE_FCNTL_TRACE]]
975 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
976 ** to the VFS about what the higher layers of the SQLite stack are doing.
977 ** This file control is used by some VFS activity tracing [shims].
978 ** The argument is a zero-terminated string. Higher layers in the
979 ** SQLite stack may generate instances of this file control if
980 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
982 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
983 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
984 ** pointer to an integer and it writes a boolean into that integer depending
985 ** on whether or not the file has been renamed, moved, or deleted since it
988 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
989 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
990 ** underlying native file handle associated with a file handle. This file
991 ** control interprets its argument as a pointer to a native file handle and
992 ** writes the resulting value there.
994 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
995 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
996 ** opcode causes the xFileControl method to swap the file handle with the one
997 ** pointed to by the pArg argument. This capability is used during testing
998 ** and only needs to be supported when SQLITE_TEST is defined.
1000 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1001 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1002 ** be advantageous to block on the next WAL lock if the lock is not immediately
1003 ** available. The WAL subsystem issues this signal during rare
1004 ** circumstances in order to fix a problem with priority inversion.
1005 ** Applications should <em>not</em> use this file-control.
1007 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1008 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1009 ** VFS should return SQLITE_NOTFOUND for this opcode.
1011 ** <li>[[SQLITE_FCNTL_RBU]]
1012 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1013 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1017 #define SQLITE_FCNTL_LOCKSTATE 1
1018 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1019 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1020 #define SQLITE_FCNTL_LAST_ERRNO 4
1021 #define SQLITE_FCNTL_SIZE_HINT 5
1022 #define SQLITE_FCNTL_CHUNK_SIZE 6
1023 #define SQLITE_FCNTL_FILE_POINTER 7
1024 #define SQLITE_FCNTL_SYNC_OMITTED 8
1025 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1026 #define SQLITE_FCNTL_PERSIST_WAL 10
1027 #define SQLITE_FCNTL_OVERWRITE 11
1028 #define SQLITE_FCNTL_VFSNAME 12
1029 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1030 #define SQLITE_FCNTL_PRAGMA 14
1031 #define SQLITE_FCNTL_BUSYHANDLER 15
1032 #define SQLITE_FCNTL_TEMPFILENAME 16
1033 #define SQLITE_FCNTL_MMAP_SIZE 18
1034 #define SQLITE_FCNTL_TRACE 19
1035 #define SQLITE_FCNTL_HAS_MOVED 20
1036 #define SQLITE_FCNTL_SYNC 21
1037 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1038 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1039 #define SQLITE_FCNTL_WAL_BLOCK 24
1040 #define SQLITE_FCNTL_ZIPVFS 25
1041 #define SQLITE_FCNTL_RBU 26
1042 #define SQLITE_FCNTL_VFS_POINTER 27
1043 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1044 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1045 #define SQLITE_FCNTL_PDB 30
1047 /* deprecated names */
1048 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1049 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1050 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1054 ** CAPI3REF: Mutex Handle
1056 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1057 ** abstract type for a mutex object. The SQLite core never looks
1058 ** at the internal representation of an [sqlite3_mutex]. It only
1059 ** deals with pointers to the [sqlite3_mutex] object.
1061 ** Mutexes are created using [sqlite3_mutex_alloc()].
1063 typedef struct sqlite3_mutex sqlite3_mutex;
1066 ** CAPI3REF: Loadable Extension Thunk
1068 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1069 ** the third parameter to entry points of [loadable extensions]. This
1070 ** structure must be typedefed in order to work around compiler warnings
1071 ** on some platforms.
1073 typedef struct sqlite3_api_routines sqlite3_api_routines;
1076 ** CAPI3REF: OS Interface Object
1078 ** An instance of the sqlite3_vfs object defines the interface between
1079 ** the SQLite core and the underlying operating system. The "vfs"
1080 ** in the name of the object stands for "virtual file system". See
1081 ** the [VFS | VFS documentation] for further information.
1083 ** The value of the iVersion field is initially 1 but may be larger in
1084 ** future versions of SQLite. Additional fields may be appended to this
1085 ** object when the iVersion value is increased. Note that the structure
1086 ** of the sqlite3_vfs object changes in the transaction between
1087 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1090 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1091 ** structure used by this VFS. mxPathname is the maximum length of
1092 ** a pathname in this VFS.
1094 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1095 ** the pNext pointer. The [sqlite3_vfs_register()]
1096 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1097 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1098 ** searches the list. Neither the application code nor the VFS
1099 ** implementation should use the pNext pointer.
1101 ** The pNext field is the only field in the sqlite3_vfs
1102 ** structure that SQLite will ever modify. SQLite will only access
1103 ** or modify this field while holding a particular static mutex.
1104 ** The application should never modify anything within the sqlite3_vfs
1105 ** object once the object has been registered.
1107 ** The zName field holds the name of the VFS module. The name must
1108 ** be unique across all VFS modules.
1110 ** [[sqlite3_vfs.xOpen]]
1111 ** ^SQLite guarantees that the zFilename parameter to xOpen
1112 ** is either a NULL pointer or string obtained
1113 ** from xFullPathname() with an optional suffix added.
1114 ** ^If a suffix is added to the zFilename parameter, it will
1115 ** consist of a single "-" character followed by no more than
1116 ** 11 alphanumeric and/or "-" characters.
1117 ** ^SQLite further guarantees that
1118 ** the string will be valid and unchanged until xClose() is
1119 ** called. Because of the previous sentence,
1120 ** the [sqlite3_file] can safely store a pointer to the
1121 ** filename if it needs to remember the filename for some reason.
1122 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1123 ** must invent its own temporary name for the file. ^Whenever the
1124 ** xFilename parameter is NULL it will also be the case that the
1125 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1127 ** The flags argument to xOpen() includes all bits set in
1128 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1129 ** or [sqlite3_open16()] is used, then flags includes at least
1130 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1131 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1132 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1134 ** ^(SQLite will also add one of the following flags to the xOpen()
1135 ** call, depending on the object being opened:
1138 ** <li> [SQLITE_OPEN_MAIN_DB]
1139 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1140 ** <li> [SQLITE_OPEN_TEMP_DB]
1141 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1142 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1143 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1144 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1145 ** <li> [SQLITE_OPEN_WAL]
1148 ** The file I/O implementation can use the object type flags to
1149 ** change the way it deals with files. For example, an application
1150 ** that does not care about crash recovery or rollback might make
1151 ** the open of a journal file a no-op. Writes to this journal would
1152 ** also be no-ops, and any attempt to read the journal would return
1153 ** SQLITE_IOERR. Or the implementation might recognize that a database
1154 ** file will be doing page-aligned sector reads and writes in a random
1155 ** order and set up its I/O subsystem accordingly.
1157 ** SQLite might also add one of the following flags to the xOpen method:
1160 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1161 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1164 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1165 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1166 ** will be set for TEMP databases and their journals, transient
1167 ** databases, and subjournals.
1169 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1170 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1171 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1172 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1173 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1174 ** be created, and that it is an error if it already exists.
1175 ** It is <i>not</i> used to indicate the file should be opened
1176 ** for exclusive access.
1178 ** ^At least szOsFile bytes of memory are allocated by SQLite
1179 ** to hold the [sqlite3_file] structure passed as the third
1180 ** argument to xOpen. The xOpen method does not have to
1181 ** allocate the structure; it should just fill it in. Note that
1182 ** the xOpen method must set the sqlite3_file.pMethods to either
1183 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1184 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1185 ** element will be valid after xOpen returns regardless of the success
1186 ** or failure of the xOpen call.
1188 ** [[sqlite3_vfs.xAccess]]
1189 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1190 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1191 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1192 ** to test whether a file is at least readable. The file can be a
1195 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1196 ** output buffer xFullPathname. The exact size of the output buffer
1197 ** is also passed as a parameter to both methods. If the output buffer
1198 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1199 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1200 ** to prevent this by setting mxPathname to a sufficiently large value.
1202 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1203 ** interfaces are not strictly a part of the filesystem, but they are
1204 ** included in the VFS structure for completeness.
1205 ** The xRandomness() function attempts to return nBytes bytes
1206 ** of good-quality randomness into zOut. The return value is
1207 ** the actual number of bytes of randomness obtained.
1208 ** The xSleep() method causes the calling thread to sleep for at
1209 ** least the number of microseconds given. ^The xCurrentTime()
1210 ** method returns a Julian Day Number for the current date and time as
1211 ** a floating point value.
1212 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1213 ** Day Number multiplied by 86400000 (the number of milliseconds in
1215 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1216 ** date and time if that method is available (if iVersion is 2 or
1217 ** greater and the function pointer is not NULL) and will fall back
1218 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1220 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1221 ** are not used by the SQLite core. These optional interfaces are provided
1222 ** by some VFSes to facilitate testing of the VFS code. By overriding
1223 ** system calls with functions under its control, a test program can
1224 ** simulate faults and error conditions that would otherwise be difficult
1225 ** or impossible to induce. The set of system calls that can be overridden
1226 ** varies from one VFS to another, and from one version of the same VFS to the
1227 ** next. Applications that use these interfaces must be prepared for any
1228 ** or all of these interfaces to be NULL or for their behavior to change
1229 ** from one release to the next. Applications must not attempt to access
1230 ** any of these methods if the iVersion of the VFS is less than 3.
1232 typedef struct sqlite3_vfs sqlite3_vfs;
1233 typedef void (*sqlite3_syscall_ptr)(void);
1234 struct sqlite3_vfs {
1235 int iVersion; /* Structure version number (currently 3) */
1236 int szOsFile; /* Size of subclassed sqlite3_file */
1237 int mxPathname; /* Maximum file pathname length */
1238 sqlite3_vfs *pNext; /* Next registered VFS */
1239 const char *zName; /* Name of this virtual file system */
1240 void *pAppData; /* Pointer to application-specific data */
1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1242 int flags, int *pOutFlags);
1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1249 void (*xDlClose)(sqlite3_vfs*, void*);
1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1251 int (*xSleep)(sqlite3_vfs*, int microseconds);
1252 int (*xCurrentTime)(sqlite3_vfs*, double*);
1253 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1255 ** The methods above are in version 1 of the sqlite_vfs object
1256 ** definition. Those that follow are added in version 2 or later
1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1261 ** Those below are for version 3 and greater.
1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1268 ** New fields may be appended in future versions. The iVersion
1269 ** value will increment whenever this happens.
1274 ** CAPI3REF: Flags for the xAccess VFS method
1276 ** These integer constants can be used as the third parameter to
1277 ** the xAccess method of an [sqlite3_vfs] object. They determine
1278 ** what kind of permissions the xAccess method is looking for.
1279 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1280 ** simply checks whether the file exists.
1281 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1282 ** checks whether the named directory is both readable and writable
1283 ** (in other words, if files can be added, removed, and renamed within
1285 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1286 ** [temp_store_directory pragma], though this could change in a future
1287 ** release of SQLite.
1288 ** With SQLITE_ACCESS_READ, the xAccess method
1289 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1290 ** currently unused, though it might be used in a future release of
1293 #define SQLITE_ACCESS_EXISTS 0
1294 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1295 #define SQLITE_ACCESS_READ 2 /* Unused */
1298 ** CAPI3REF: Flags for the xShmLock VFS method
1300 ** These integer constants define the various locking operations
1301 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1302 ** following are the only legal combinations of flags to the
1306 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1307 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1308 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1309 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1312 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1313 ** was given on the corresponding lock.
1315 ** The xShmLock method can transition between unlocked and SHARED or
1316 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1319 #define SQLITE_SHM_UNLOCK 1
1320 #define SQLITE_SHM_LOCK 2
1321 #define SQLITE_SHM_SHARED 4
1322 #define SQLITE_SHM_EXCLUSIVE 8
1325 ** CAPI3REF: Maximum xShmLock index
1327 ** The xShmLock method on [sqlite3_io_methods] may use values
1328 ** between 0 and this upper bound as its "offset" argument.
1329 ** The SQLite core will never attempt to acquire or release a
1330 ** lock outside of this range
1332 #define SQLITE_SHM_NLOCK 8
1336 ** CAPI3REF: Initialize The SQLite Library
1338 ** ^The sqlite3_initialize() routine initializes the
1339 ** SQLite library. ^The sqlite3_shutdown() routine
1340 ** deallocates any resources that were allocated by sqlite3_initialize().
1341 ** These routines are designed to aid in process initialization and
1342 ** shutdown on embedded systems. Workstation applications using
1343 ** SQLite normally do not need to invoke either of these routines.
1345 ** A call to sqlite3_initialize() is an "effective" call if it is
1346 ** the first time sqlite3_initialize() is invoked during the lifetime of
1347 ** the process, or if it is the first time sqlite3_initialize() is invoked
1348 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1349 ** of sqlite3_initialize() does any initialization. All other calls
1350 ** are harmless no-ops.)^
1352 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1353 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1354 ** an effective call to sqlite3_shutdown() does any deinitialization.
1355 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1357 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1358 ** is not. The sqlite3_shutdown() interface must only be called from a
1359 ** single thread. All open [database connections] must be closed and all
1360 ** other SQLite resources must be deallocated prior to invoking
1361 ** sqlite3_shutdown().
1363 ** Among other things, ^sqlite3_initialize() will invoke
1364 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1365 ** will invoke sqlite3_os_end().
1367 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1368 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1369 ** the library (perhaps it is unable to allocate a needed resource such
1370 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1372 ** ^The sqlite3_initialize() routine is called internally by many other
1373 ** SQLite interfaces so that an application usually does not need to
1374 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1375 ** calls sqlite3_initialize() so the SQLite library will be automatically
1376 ** initialized when [sqlite3_open()] is called if it has not be initialized
1377 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1378 ** compile-time option, then the automatic calls to sqlite3_initialize()
1379 ** are omitted and the application must call sqlite3_initialize() directly
1380 ** prior to using any other SQLite interface. For maximum portability,
1381 ** it is recommended that applications always invoke sqlite3_initialize()
1382 ** directly prior to using any other SQLite interface. Future releases
1383 ** of SQLite may require this. In other words, the behavior exhibited
1384 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1385 ** default behavior in some future release of SQLite.
1387 ** The sqlite3_os_init() routine does operating-system specific
1388 ** initialization of the SQLite library. The sqlite3_os_end()
1389 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1390 ** performed by these routines include allocation or deallocation
1391 ** of static resources, initialization of global variables,
1392 ** setting up a default [sqlite3_vfs] module, or setting up
1393 ** a default configuration using [sqlite3_config()].
1395 ** The application should never invoke either sqlite3_os_init()
1396 ** or sqlite3_os_end() directly. The application should only invoke
1397 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1398 ** interface is called automatically by sqlite3_initialize() and
1399 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1400 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1401 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1402 ** When [custom builds | built for other platforms]
1403 ** (using the [SQLITE_OS_OTHER=1] compile-time
1404 ** option) the application must supply a suitable implementation for
1405 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1406 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1407 ** must return [SQLITE_OK] on success and some other [error code] upon
1410 SQLITE_API int sqlite3_initialize(void);
1411 SQLITE_API int sqlite3_shutdown(void);
1412 SQLITE_API int sqlite3_os_init(void);
1413 SQLITE_API int sqlite3_os_end(void);
1416 ** CAPI3REF: Configuring The SQLite Library
1418 ** The sqlite3_config() interface is used to make global configuration
1419 ** changes to SQLite in order to tune SQLite to the specific needs of
1420 ** the application. The default configuration is recommended for most
1421 ** applications and so this routine is usually not necessary. It is
1422 ** provided to support rare applications with unusual needs.
1424 ** <b>The sqlite3_config() interface is not threadsafe. The application
1425 ** must ensure that no other SQLite interfaces are invoked by other
1426 ** threads while sqlite3_config() is running.</b>
1428 ** The sqlite3_config() interface
1429 ** may only be invoked prior to library initialization using
1430 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1431 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1432 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1433 ** Note, however, that ^sqlite3_config() can be called as part of the
1434 ** implementation of an application-defined [sqlite3_os_init()].
1436 ** The first argument to sqlite3_config() is an integer
1437 ** [configuration option] that determines
1438 ** what property of SQLite is to be configured. Subsequent arguments
1439 ** vary depending on the [configuration option]
1440 ** in the first argument.
1442 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1443 ** ^If the option is unknown or SQLite is unable to set the option
1444 ** then this routine returns a non-zero [error code].
1446 SQLITE_API int sqlite3_config(int, ...);
1449 ** CAPI3REF: Configure database connections
1452 ** The sqlite3_db_config() interface is used to make configuration
1453 ** changes to a [database connection]. The interface is similar to
1454 ** [sqlite3_config()] except that the changes apply to a single
1455 ** [database connection] (specified in the first argument).
1457 ** The second argument to sqlite3_db_config(D,V,...) is the
1458 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1459 ** that indicates what aspect of the [database connection] is being configured.
1460 ** Subsequent arguments vary depending on the configuration verb.
1462 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1463 ** the call is considered successful.
1465 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1468 ** CAPI3REF: Memory Allocation Routines
1470 ** An instance of this object defines the interface between SQLite
1471 ** and low-level memory allocation routines.
1473 ** This object is used in only one place in the SQLite interface.
1474 ** A pointer to an instance of this object is the argument to
1475 ** [sqlite3_config()] when the configuration option is
1476 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1477 ** By creating an instance of this object
1478 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1479 ** during configuration, an application can specify an alternative
1480 ** memory allocation subsystem for SQLite to use for all of its
1481 ** dynamic memory needs.
1483 ** Note that SQLite comes with several [built-in memory allocators]
1484 ** that are perfectly adequate for the overwhelming majority of applications
1485 ** and that this object is only useful to a tiny minority of applications
1486 ** with specialized memory allocation requirements. This object is
1487 ** also used during testing of SQLite in order to specify an alternative
1488 ** memory allocator that simulates memory out-of-memory conditions in
1489 ** order to verify that SQLite recovers gracefully from such
1492 ** The xMalloc, xRealloc, and xFree methods must work like the
1493 ** malloc(), realloc() and free() functions from the standard C library.
1494 ** ^SQLite guarantees that the second argument to
1495 ** xRealloc is always a value returned by a prior call to xRoundup.
1497 ** xSize should return the allocated size of a memory allocation
1498 ** previously obtained from xMalloc or xRealloc. The allocated size
1499 ** is always at least as big as the requested size but may be larger.
1501 ** The xRoundup method returns what would be the allocated size of
1502 ** a memory allocation given a particular requested size. Most memory
1503 ** allocators round up memory allocations at least to the next multiple
1504 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1505 ** Every memory allocation request coming in through [sqlite3_malloc()]
1506 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1507 ** that causes the corresponding memory allocation to fail.
1509 ** The xInit method initializes the memory allocator. For example,
1510 ** it might allocate any require mutexes or initialize internal data
1511 ** structures. The xShutdown method is invoked (indirectly) by
1512 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1513 ** by xInit. The pAppData pointer is used as the only parameter to
1514 ** xInit and xShutdown.
1516 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1517 ** the xInit method, so the xInit method need not be threadsafe. The
1518 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1519 ** not need to be threadsafe either. For all other methods, SQLite
1520 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1521 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1522 ** it is by default) and so the methods are automatically serialized.
1523 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1524 ** methods must be threadsafe or else make their own arrangements for
1527 ** SQLite will never invoke xInit() more than once without an intervening
1528 ** call to xShutdown().
1530 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1531 struct sqlite3_mem_methods {
1532 void *(*xMalloc)(int); /* Memory allocation function */
1533 void (*xFree)(void*); /* Free a prior allocation */
1534 void *(*xRealloc)(void*,int); /* Resize an allocation */
1535 int (*xSize)(void*); /* Return the size of an allocation */
1536 int (*xRoundup)(int); /* Round up request size to allocation size */
1537 int (*xInit)(void*); /* Initialize the memory allocator */
1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1539 void *pAppData; /* Argument to xInit() and xShutdown() */
1543 ** CAPI3REF: Configuration Options
1544 ** KEYWORDS: {configuration option}
1546 ** These constants are the available integer configuration options that
1547 ** can be passed as the first argument to the [sqlite3_config()] interface.
1549 ** New configuration options may be added in future releases of SQLite.
1550 ** Existing configuration options might be discontinued. Applications
1551 ** should check the return code from [sqlite3_config()] to make sure that
1552 ** the call worked. The [sqlite3_config()] interface will return a
1553 ** non-zero [error code] if a discontinued or unsupported configuration option
1557 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1558 ** <dd>There are no arguments to this option. ^This option sets the
1559 ** [threading mode] to Single-thread. In other words, it disables
1560 ** all mutexing and puts SQLite into a mode where it can only be used
1561 ** by a single thread. ^If SQLite is compiled with
1562 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1563 ** it is not possible to change the [threading mode] from its default
1564 ** value of Single-thread and so [sqlite3_config()] will return
1565 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1566 ** configuration option.</dd>
1568 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1569 ** <dd>There are no arguments to this option. ^This option sets the
1570 ** [threading mode] to Multi-thread. In other words, it disables
1571 ** mutexing on [database connection] and [prepared statement] objects.
1572 ** The application is responsible for serializing access to
1573 ** [database connections] and [prepared statements]. But other mutexes
1574 ** are enabled so that SQLite will be safe to use in a multi-threaded
1575 ** environment as long as no two threads attempt to use the same
1576 ** [database connection] at the same time. ^If SQLite is compiled with
1577 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1578 ** it is not possible to set the Multi-thread [threading mode] and
1579 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1580 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1582 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1583 ** <dd>There are no arguments to this option. ^This option sets the
1584 ** [threading mode] to Serialized. In other words, this option enables
1585 ** all mutexes including the recursive
1586 ** mutexes on [database connection] and [prepared statement] objects.
1587 ** In this mode (which is the default when SQLite is compiled with
1588 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1589 ** to [database connections] and [prepared statements] so that the
1590 ** application is free to use the same [database connection] or the
1591 ** same [prepared statement] in different threads at the same time.
1592 ** ^If SQLite is compiled with
1593 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1594 ** it is not possible to set the Serialized [threading mode] and
1595 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1596 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1598 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1599 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1600 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1601 ** The argument specifies
1602 ** alternative low-level memory allocation routines to be used in place of
1603 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1604 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1605 ** before the [sqlite3_config()] call returns.</dd>
1607 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1608 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1609 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1610 ** The [sqlite3_mem_methods]
1611 ** structure is filled with the currently defined memory allocation routines.)^
1612 ** This option can be used to overload the default memory allocation
1613 ** routines with a wrapper that simulations memory allocation failure or
1614 ** tracks memory usage, for example. </dd>
1616 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1617 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1618 ** interpreted as a boolean, which enables or disables the collection of
1619 ** memory allocation statistics. ^(When memory allocation statistics are
1620 ** disabled, the following SQLite interfaces become non-operational:
1622 ** <li> [sqlite3_memory_used()]
1623 ** <li> [sqlite3_memory_highwater()]
1624 ** <li> [sqlite3_soft_heap_limit64()]
1625 ** <li> [sqlite3_status64()]
1627 ** ^Memory allocation statistics are enabled by default unless SQLite is
1628 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1629 ** allocation statistics are disabled by default.
1632 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1633 ** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
1634 ** that SQLite can use for scratch memory. ^(There are three arguments
1635 ** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte
1636 ** aligned memory buffer from which the scratch allocations will be
1637 ** drawn, the size of each scratch allocation (sz),
1638 ** and the maximum number of scratch allocations (N).)^
1639 ** The first argument must be a pointer to an 8-byte aligned buffer
1640 ** of at least sz*N bytes of memory.
1641 ** ^SQLite will not use more than one scratch buffers per thread.
1642 ** ^SQLite will never request a scratch buffer that is more than 6
1643 ** times the database page size.
1644 ** ^If SQLite needs needs additional
1645 ** scratch memory beyond what is provided by this configuration option, then
1646 ** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
1647 ** ^When the application provides any amount of scratch memory using
1648 ** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
1649 ** [sqlite3_malloc|heap allocations].
1650 ** This can help [Robson proof|prevent memory allocation failures] due to heap
1651 ** fragmentation in low-memory embedded systems.
1654 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1655 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1656 ** that SQLite can use for the database page cache with the default page
1657 ** cache implementation.
1658 ** This configuration option is a no-op if an application-define page
1659 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1660 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1661 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1662 ** and the number of cache lines (N).
1663 ** The sz argument should be the size of the largest database page
1664 ** (a power of two between 512 and 65536) plus some extra bytes for each
1665 ** page header. ^The number of extra bytes needed by the page header
1666 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1667 ** ^It is harmless, apart from the wasted memory,
1668 ** for the sz parameter to be larger than necessary. The pMem
1669 ** argument must be either a NULL pointer or a pointer to an 8-byte
1670 ** aligned block of memory of at least sz*N bytes, otherwise
1671 ** subsequent behavior is undefined.
1672 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1673 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1674 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1676 ** ^If pMem is NULL and N is non-zero, then each database connection
1677 ** does an initial bulk allocation for page cache memory
1678 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1679 ** of -1024*N bytes if N is negative, . ^If additional
1680 ** page cache memory is needed beyond what is provided by the initial
1681 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1682 ** additional cache line. </dd>
1684 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1685 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1686 ** that SQLite will use for all of its dynamic memory allocation needs
1687 ** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
1688 ** [SQLITE_CONFIG_PAGECACHE].
1689 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1690 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1691 ** [SQLITE_ERROR] if invoked otherwise.
1692 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1693 ** An 8-byte aligned pointer to the memory,
1694 ** the number of bytes in the memory buffer, and the minimum allocation size.
1695 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1696 ** to using its default memory allocator (the system malloc() implementation),
1697 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1698 ** memory pointer is not NULL then the alternative memory
1699 ** allocator is engaged to handle all of SQLites memory allocation needs.
1700 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1701 ** boundary or subsequent behavior of SQLite will be undefined.
1702 ** The minimum allocation size is capped at 2**12. Reasonable values
1703 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1705 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1706 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1707 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1708 ** The argument specifies alternative low-level mutex routines to be used
1709 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1710 ** the content of the [sqlite3_mutex_methods] structure before the call to
1711 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1712 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1713 ** the entire mutexing subsystem is omitted from the build and hence calls to
1714 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1715 ** return [SQLITE_ERROR].</dd>
1717 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1718 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1719 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1720 ** [sqlite3_mutex_methods]
1721 ** structure is filled with the currently defined mutex routines.)^
1722 ** This option can be used to overload the default mutex allocation
1723 ** routines with a wrapper used to track mutex usage for performance
1724 ** profiling or testing, for example. ^If SQLite is compiled with
1725 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1726 ** the entire mutexing subsystem is omitted from the build and hence calls to
1727 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1728 ** return [SQLITE_ERROR].</dd>
1730 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1731 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1732 ** the default size of lookaside memory on each [database connection].
1733 ** The first argument is the
1734 ** size of each lookaside buffer slot and the second is the number of
1735 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1736 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1737 ** option to [sqlite3_db_config()] can be used to change the lookaside
1738 ** configuration on individual connections.)^ </dd>
1740 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1741 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1742 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1743 ** the interface to a custom page cache implementation.)^
1744 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1746 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1747 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1748 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1749 ** the current page cache implementation into that object.)^ </dd>
1751 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1752 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1753 ** global [error log].
1754 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1755 ** function with a call signature of void(*)(void*,int,const char*),
1756 ** and a pointer to void. ^If the function pointer is not NULL, it is
1757 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1758 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1759 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1760 ** passed through as the first parameter to the application-defined logger
1761 ** function whenever that function is invoked. ^The second parameter to
1762 ** the logger function is a copy of the first parameter to the corresponding
1763 ** [sqlite3_log()] call and is intended to be a [result code] or an
1764 ** [extended result code]. ^The third parameter passed to the logger is
1765 ** log message after formatting via [sqlite3_snprintf()].
1766 ** The SQLite logging interface is not reentrant; the logger function
1767 ** supplied by the application must not invoke any SQLite interface.
1768 ** In a multi-threaded application, the application-defined logger
1769 ** function must be threadsafe. </dd>
1771 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1772 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1773 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1774 ** then URI handling is globally disabled.)^ ^If URI handling is globally
1775 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1776 ** [sqlite3_open16()] or
1777 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1778 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1779 ** connection is opened. ^If it is globally disabled, filenames are
1780 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1781 ** database connection is opened. ^(By default, URI handling is globally
1782 ** disabled. The default value may be changed by compiling with the
1783 ** [SQLITE_USE_URI] symbol defined.)^
1785 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1786 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1787 ** argument which is interpreted as a boolean in order to enable or disable
1788 ** the use of covering indices for full table scans in the query optimizer.
1789 ** ^The default setting is determined
1790 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1791 ** if that compile-time option is omitted.
1792 ** The ability to disable the use of covering indices for full table scans
1793 ** is because some incorrectly coded legacy applications might malfunction
1794 ** when the optimization is enabled. Providing the ability to
1795 ** disable the optimization allows the older, buggy application code to work
1796 ** without change even with newer versions of SQLite.
1798 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1799 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1800 ** <dd> These options are obsolete and should not be used by new code.
1801 ** They are retained for backwards compatibility but are now no-ops.
1804 ** [[SQLITE_CONFIG_SQLLOG]]
1805 ** <dt>SQLITE_CONFIG_SQLLOG
1806 ** <dd>This option is only available if sqlite is compiled with the
1807 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1808 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1809 ** The second should be of type (void*). The callback is invoked by the library
1810 ** in three separate circumstances, identified by the value passed as the
1811 ** fourth parameter. If the fourth parameter is 0, then the database connection
1812 ** passed as the second argument has just been opened. The third argument
1813 ** points to a buffer containing the name of the main database file. If the
1814 ** fourth parameter is 1, then the SQL statement that the third parameter
1815 ** points to has just been executed. Or, if the fourth parameter is 2, then
1816 ** the connection being passed as the second parameter is being closed. The
1817 ** third parameter is passed NULL In this case. An example of using this
1818 ** configuration option can be seen in the "test_sqllog.c" source file in
1819 ** the canonical SQLite source tree.</dd>
1821 ** [[SQLITE_CONFIG_MMAP_SIZE]]
1822 ** <dt>SQLITE_CONFIG_MMAP_SIZE
1823 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1824 ** that are the default mmap size limit (the default setting for
1825 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1826 ** ^The default setting can be overridden by each database connection using
1827 ** either the [PRAGMA mmap_size] command, or by using the
1828 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1829 ** will be silently truncated if necessary so that it does not exceed the
1830 ** compile-time maximum mmap size set by the
1831 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1832 ** ^If either argument to this option is negative, then that argument is
1833 ** changed to its compile-time default.
1835 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1836 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1837 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1838 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1839 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1840 ** that specifies the maximum size of the created heap.
1842 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1843 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1844 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1845 ** is a pointer to an integer and writes into that integer the number of extra
1846 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1847 ** The amount of extra space required can change depending on the compiler,
1848 ** target platform, and SQLite version.
1850 ** [[SQLITE_CONFIG_PMASZ]]
1851 ** <dt>SQLITE_CONFIG_PMASZ
1852 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1853 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1854 ** sorter to that integer. The default minimum PMA Size is set by the
1855 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1856 ** to help with sort operations when multithreaded sorting
1857 ** is enabled (using the [PRAGMA threads] command) and the amount of content
1858 ** to be sorted exceeds the page size times the minimum of the
1859 ** [PRAGMA cache_size] setting and this value.
1861 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1862 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1863 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1864 ** becomes the [statement journal] spill-to-disk threshold.
1865 ** [Statement journals] are held in memory until their size (in bytes)
1866 ** exceeds this threshold, at which point they are written to disk.
1867 ** Or if the threshold is -1, statement journals are always held
1868 ** exclusively in memory.
1869 ** Since many statement journals never become large, setting the spill
1870 ** threshold to a value such as 64KiB can greatly reduce the amount of
1871 ** I/O required to support statement rollback.
1872 ** The default value for this setting is controlled by the
1873 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
1876 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1877 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1878 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1879 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1880 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1881 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1882 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1883 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1884 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1885 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1886 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1887 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1888 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1889 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
1890 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1891 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1892 #define SQLITE_CONFIG_URI 17 /* int */
1893 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1894 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1895 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1896 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1897 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1898 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
1899 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
1900 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
1901 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
1904 ** CAPI3REF: Database Connection Configuration Options
1906 ** These constants are the available integer configuration options that
1907 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1909 ** New configuration options may be added in future releases of SQLite.
1910 ** Existing configuration options might be discontinued. Applications
1911 ** should check the return code from [sqlite3_db_config()] to make sure that
1912 ** the call worked. ^The [sqlite3_db_config()] interface will return a
1913 ** non-zero [error code] if a discontinued or unsupported configuration option
1917 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1918 ** <dd> ^This option takes three additional arguments that determine the
1919 ** [lookaside memory allocator] configuration for the [database connection].
1920 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1921 ** pointer to a memory buffer to use for lookaside memory.
1922 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1923 ** may be NULL in which case SQLite will allocate the
1924 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1925 ** size of each lookaside buffer slot. ^The third argument is the number of
1926 ** slots. The size of the buffer in the first argument must be greater than
1927 ** or equal to the product of the second and third arguments. The buffer
1928 ** must be aligned to an 8-byte boundary. ^If the second argument to
1929 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1930 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1931 ** configuration for a database connection can only be changed when that
1932 ** connection is not currently using lookaside memory, or in other words
1933 ** when the "current value" returned by
1934 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1935 ** Any attempt to change the lookaside memory configuration when lookaside
1936 ** memory is in use leaves the configuration unchanged and returns
1937 ** [SQLITE_BUSY].)^</dd>
1939 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1940 ** <dd> ^This option is used to enable or disable the enforcement of
1941 ** [foreign key constraints]. There should be two additional arguments.
1942 ** The first argument is an integer which is 0 to disable FK enforcement,
1943 ** positive to enable FK enforcement or negative to leave FK enforcement
1944 ** unchanged. The second parameter is a pointer to an integer into which
1945 ** is written 0 or 1 to indicate whether FK enforcement is off or on
1946 ** following this call. The second parameter may be a NULL pointer, in
1947 ** which case the FK enforcement setting is not reported back. </dd>
1949 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1950 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1951 ** There should be two additional arguments.
1952 ** The first argument is an integer which is 0 to disable triggers,
1953 ** positive to enable triggers or negative to leave the setting unchanged.
1954 ** The second parameter is a pointer to an integer into which
1955 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1956 ** following this call. The second parameter may be a NULL pointer, in
1957 ** which case the trigger setting is not reported back. </dd>
1959 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
1960 ** <dd> ^This option is used to enable or disable the two-argument
1961 ** version of the [fts3_tokenizer()] function which is part of the
1962 ** [FTS3] full-text search engine extension.
1963 ** There should be two additional arguments.
1964 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
1965 ** positive to enable fts3_tokenizer() or negative to leave the setting
1967 ** The second parameter is a pointer to an integer into which
1968 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
1969 ** following this call. The second parameter may be a NULL pointer, in
1970 ** which case the new setting is not reported back. </dd>
1972 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
1973 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
1974 ** interface independently of the [load_extension()] SQL function.
1975 ** The [sqlite3_enable_load_extension()] API enables or disables both the
1976 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
1977 ** There should be two additional arguments.
1978 ** When the first argument to this interface is 1, then only the C-API is
1979 ** enabled and the SQL function remains disabled. If the first argument to
1980 ** this interface is 0, then both the C-API and the SQL function are disabled.
1981 ** If the first argument is -1, then no changes are made to state of either the
1982 ** C-API or the SQL function.
1983 ** The second parameter is a pointer to an integer into which
1984 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
1985 ** is disabled or enabled following this call. The second parameter may
1986 ** be a NULL pointer, in which case the new setting is not reported back.
1989 ** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
1990 ** <dd> ^This option is used to change the name of the "main" database
1991 ** schema. ^The sole argument is a pointer to a constant UTF8 string
1992 ** which will become the new schema name in place of "main". ^SQLite
1993 ** does not make a copy of the new main schema name string, so the application
1994 ** must ensure that the argument passed into this DBCONFIG option is unchanged
1995 ** until after the database connection closes.
1998 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
1999 ** <dd> Usually, when a database in wal mode is closed or detached from a
2000 ** database handle, SQLite checks if this will mean that there are now no
2001 ** connections at all to the database. If so, it performs a checkpoint
2002 ** operation before closing the connection. This option may be used to
2003 ** override this behaviour. The first parameter passed to this operation
2004 ** is an integer - non-zero to disable checkpoints-on-close, or zero (the
2005 ** default) to enable them. The second parameter is a pointer to an integer
2006 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2007 ** have been disabled - 0 if they are not disabled, 1 if they are.
2012 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2013 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2014 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2015 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2016 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2017 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2018 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2022 ** CAPI3REF: Enable Or Disable Extended Result Codes
2025 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2026 ** [extended result codes] feature of SQLite. ^The extended result
2027 ** codes are disabled by default for historical compatibility.
2029 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2032 ** CAPI3REF: Last Insert Rowid
2035 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2036 ** has a unique 64-bit signed
2037 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2038 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2039 ** names are not also used by explicitly declared columns. ^If
2040 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2041 ** is another alias for the rowid.
2043 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2044 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2045 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2046 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2047 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2050 ** As well as being set automatically as rows are inserted into database
2051 ** tables, the value returned by this function may be set explicitly by
2052 ** [sqlite3_set_last_insert_rowid()]
2054 ** Some virtual table implementations may INSERT rows into rowid tables as
2055 ** part of committing a transaction (e.g. to flush data accumulated in memory
2056 ** to disk). In this case subsequent calls to this function return the rowid
2057 ** associated with these internal INSERT operations, which leads to
2058 ** unintuitive results. Virtual table implementations that do write to rowid
2059 ** tables in this way can avoid this problem by restoring the original
2060 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2061 ** control to the user.
2063 ** ^(If an [INSERT] occurs within a trigger then this routine will
2064 ** return the [rowid] of the inserted row as long as the trigger is
2065 ** running. Once the trigger program ends, the value returned
2066 ** by this routine reverts to what it was before the trigger was fired.)^
2068 ** ^An [INSERT] that fails due to a constraint violation is not a
2069 ** successful [INSERT] and does not change the value returned by this
2070 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2071 ** and INSERT OR ABORT make no changes to the return value of this
2072 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2073 ** encounters a constraint violation, it does not fail. The
2074 ** INSERT continues to completion after deleting rows that caused
2075 ** the constraint problem so INSERT OR REPLACE will always change
2076 ** the return value of this interface.)^
2078 ** ^For the purposes of this routine, an [INSERT] is considered to
2079 ** be successful even if it is subsequently rolled back.
2081 ** This function is accessible to SQL statements via the
2082 ** [last_insert_rowid() SQL function].
2084 ** If a separate thread performs a new [INSERT] on the same
2085 ** database connection while the [sqlite3_last_insert_rowid()]
2086 ** function is running and thus changes the last insert [rowid],
2087 ** then the value returned by [sqlite3_last_insert_rowid()] is
2088 ** unpredictable and might not equal either the old or the new
2089 ** last insert [rowid].
2091 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2094 ** CAPI3REF: Set the Last Insert Rowid value.
2097 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2098 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2099 ** without inserting a row into the database.
2101 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2104 ** CAPI3REF: Count The Number Of Rows Modified
2107 ** ^This function returns the number of rows modified, inserted or
2108 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2109 ** statement on the database connection specified by the only parameter.
2110 ** ^Executing any other type of SQL statement does not modify the value
2111 ** returned by this function.
2113 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2114 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2115 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2117 ** Changes to a view that are intercepted by
2118 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2119 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2120 ** DELETE statement run on a view is always zero. Only changes made to real
2121 ** tables are counted.
2123 ** Things are more complicated if the sqlite3_changes() function is
2124 ** executed while a trigger program is running. This may happen if the
2125 ** program uses the [changes() SQL function], or if some other callback
2126 ** function invokes sqlite3_changes() directly. Essentially:
2129 ** <li> ^(Before entering a trigger program the value returned by
2130 ** sqlite3_changes() function is saved. After the trigger program
2131 ** has finished, the original value is restored.)^
2133 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2134 ** statement sets the value returned by sqlite3_changes()
2135 ** upon completion as normal. Of course, this value will not include
2136 ** any changes performed by sub-triggers, as the sqlite3_changes()
2137 ** value will be saved and restored after each sub-trigger has run.)^
2140 ** ^This means that if the changes() SQL function (or similar) is used
2141 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2142 ** returns the value as set when the calling statement began executing.
2143 ** ^If it is used by the second or subsequent such statement within a trigger
2144 ** program, the value returned reflects the number of rows modified by the
2145 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2147 ** See also the [sqlite3_total_changes()] interface, the
2148 ** [count_changes pragma], and the [changes() SQL function].
2150 ** If a separate thread makes changes on the same database connection
2151 ** while [sqlite3_changes()] is running then the value returned
2152 ** is unpredictable and not meaningful.
2154 SQLITE_API int sqlite3_changes(sqlite3*);
2157 ** CAPI3REF: Total Number Of Rows Modified
2160 ** ^This function returns the total number of rows inserted, modified or
2161 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2162 ** since the database connection was opened, including those executed as
2163 ** part of trigger programs. ^Executing any other type of SQL statement
2164 ** does not affect the value returned by sqlite3_total_changes().
2166 ** ^Changes made as part of [foreign key actions] are included in the
2167 ** count, but those made as part of REPLACE constraint resolution are
2168 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2171 ** See also the [sqlite3_changes()] interface, the
2172 ** [count_changes pragma], and the [total_changes() SQL function].
2174 ** If a separate thread makes changes on the same database connection
2175 ** while [sqlite3_total_changes()] is running then the value
2176 ** returned is unpredictable and not meaningful.
2178 SQLITE_API int sqlite3_total_changes(sqlite3*);
2181 ** CAPI3REF: Interrupt A Long-Running Query
2184 ** ^This function causes any pending database operation to abort and
2185 ** return at its earliest opportunity. This routine is typically
2186 ** called in response to a user action such as pressing "Cancel"
2187 ** or Ctrl-C where the user wants a long query operation to halt
2190 ** ^It is safe to call this routine from a thread different from the
2191 ** thread that is currently running the database operation. But it
2192 ** is not safe to call this routine with a [database connection] that
2193 ** is closed or might close before sqlite3_interrupt() returns.
2195 ** ^If an SQL operation is very nearly finished at the time when
2196 ** sqlite3_interrupt() is called, then it might not have an opportunity
2197 ** to be interrupted and might continue to completion.
2199 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2200 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2201 ** that is inside an explicit transaction, then the entire transaction
2202 ** will be rolled back automatically.
2204 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2205 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2206 ** that are started after the sqlite3_interrupt() call and before the
2207 ** running statements reaches zero are interrupted as if they had been
2208 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2209 ** that are started after the running statement count reaches zero are
2210 ** not effected by the sqlite3_interrupt().
2211 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2212 ** SQL statements is a no-op and has no effect on SQL statements
2213 ** that are started after the sqlite3_interrupt() call returns.
2215 SQLITE_API void sqlite3_interrupt(sqlite3*);
2218 ** CAPI3REF: Determine If An SQL Statement Is Complete
2220 ** These routines are useful during command-line input to determine if the
2221 ** currently entered text seems to form a complete SQL statement or
2222 ** if additional input is needed before sending the text into
2223 ** SQLite for parsing. ^These routines return 1 if the input string
2224 ** appears to be a complete SQL statement. ^A statement is judged to be
2225 ** complete if it ends with a semicolon token and is not a prefix of a
2226 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2227 ** string literals or quoted identifier names or comments are not
2228 ** independent tokens (they are part of the token in which they are
2229 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2230 ** and comments that follow the final semicolon are ignored.
2232 ** ^These routines return 0 if the statement is incomplete. ^If a
2233 ** memory allocation fails, then SQLITE_NOMEM is returned.
2235 ** ^These routines do not parse the SQL statements thus
2236 ** will not detect syntactically incorrect SQL.
2238 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2239 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2240 ** automatically by sqlite3_complete16(). If that initialization fails,
2241 ** then the return value from sqlite3_complete16() will be non-zero
2242 ** regardless of whether or not the input SQL is complete.)^
2244 ** The input to [sqlite3_complete()] must be a zero-terminated
2247 ** The input to [sqlite3_complete16()] must be a zero-terminated
2248 ** UTF-16 string in native byte order.
2250 SQLITE_API int sqlite3_complete(const char *sql);
2251 SQLITE_API int sqlite3_complete16(const void *sql);
2254 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2255 ** KEYWORDS: {busy-handler callback} {busy handler}
2258 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2259 ** that might be invoked with argument P whenever
2260 ** an attempt is made to access a database table associated with
2261 ** [database connection] D when another thread
2262 ** or process has the table locked.
2263 ** The sqlite3_busy_handler() interface is used to implement
2264 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2266 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2267 ** is returned immediately upon encountering the lock. ^If the busy callback
2268 ** is not NULL, then the callback might be invoked with two arguments.
2270 ** ^The first argument to the busy handler is a copy of the void* pointer which
2271 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2272 ** the busy handler callback is the number of times that the busy handler has
2273 ** been invoked previously for the same locking event. ^If the
2274 ** busy callback returns 0, then no additional attempts are made to
2275 ** access the database and [SQLITE_BUSY] is returned
2276 ** to the application.
2277 ** ^If the callback returns non-zero, then another attempt
2278 ** is made to access the database and the cycle repeats.
2280 ** The presence of a busy handler does not guarantee that it will be invoked
2281 ** when there is lock contention. ^If SQLite determines that invoking the busy
2282 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2283 ** to the application instead of invoking the
2285 ** Consider a scenario where one process is holding a read lock that
2286 ** it is trying to promote to a reserved lock and
2287 ** a second process is holding a reserved lock that it is trying
2288 ** to promote to an exclusive lock. The first process cannot proceed
2289 ** because it is blocked by the second and the second process cannot
2290 ** proceed because it is blocked by the first. If both processes
2291 ** invoke the busy handlers, neither will make any progress. Therefore,
2292 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2293 ** will induce the first process to release its read lock and allow
2294 ** the second process to proceed.
2296 ** ^The default busy callback is NULL.
2298 ** ^(There can only be a single busy handler defined for each
2299 ** [database connection]. Setting a new busy handler clears any
2300 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2301 ** or evaluating [PRAGMA busy_timeout=N] will change the
2302 ** busy handler and thus clear any previously set busy handler.
2304 ** The busy callback should not take any actions which modify the
2305 ** database connection that invoked the busy handler. In other words,
2306 ** the busy handler is not reentrant. Any such actions
2307 ** result in undefined behavior.
2309 ** A busy handler must not close the database connection
2310 ** or [prepared statement] that invoked the busy handler.
2312 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2315 ** CAPI3REF: Set A Busy Timeout
2318 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2319 ** for a specified amount of time when a table is locked. ^The handler
2320 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2321 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2322 ** the handler returns 0 which causes [sqlite3_step()] to return
2325 ** ^Calling this routine with an argument less than or equal to zero
2326 ** turns off all busy handlers.
2328 ** ^(There can only be a single busy handler for a particular
2329 ** [database connection] at any given moment. If another busy handler
2330 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2331 ** this routine, that other busy handler is cleared.)^
2333 ** See also: [PRAGMA busy_timeout]
2335 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2338 ** CAPI3REF: Convenience Routines For Running Queries
2341 ** This is a legacy interface that is preserved for backwards compatibility.
2342 ** Use of this interface is not recommended.
2344 ** Definition: A <b>result table</b> is memory data structure created by the
2345 ** [sqlite3_get_table()] interface. A result table records the
2346 ** complete query results from one or more queries.
2348 ** The table conceptually has a number of rows and columns. But
2349 ** these numbers are not part of the result table itself. These
2350 ** numbers are obtained separately. Let N be the number of rows
2351 ** and M be the number of columns.
2353 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2354 ** There are (N+1)*M elements in the array. The first M pointers point
2355 ** to zero-terminated strings that contain the names of the columns.
2356 ** The remaining entries all point to query results. NULL values result
2357 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2358 ** string representation as returned by [sqlite3_column_text()].
2360 ** A result table might consist of one or more memory allocations.
2361 ** It is not safe to pass a result table directly to [sqlite3_free()].
2362 ** A result table should be deallocated using [sqlite3_free_table()].
2364 ** ^(As an example of the result table format, suppose a query result
2367 ** <blockquote><pre>
2369 ** -----------------------
2373 ** </pre></blockquote>
2375 ** There are two column (M==2) and three rows (N==3). Thus the
2376 ** result table has 8 entries. Suppose the result table is stored
2377 ** in an array names azResult. Then azResult holds this content:
2379 ** <blockquote><pre>
2380 ** azResult[0] = "Name";
2381 ** azResult[1] = "Age";
2382 ** azResult[2] = "Alice";
2383 ** azResult[3] = "43";
2384 ** azResult[4] = "Bob";
2385 ** azResult[5] = "28";
2386 ** azResult[6] = "Cindy";
2387 ** azResult[7] = "21";
2388 ** </pre></blockquote>)^
2390 ** ^The sqlite3_get_table() function evaluates one or more
2391 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2392 ** string of its 2nd parameter and returns a result table to the
2393 ** pointer given in its 3rd parameter.
2395 ** After the application has finished with the result from sqlite3_get_table(),
2396 ** it must pass the result table pointer to sqlite3_free_table() in order to
2397 ** release the memory that was malloced. Because of the way the
2398 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2399 ** function must not try to call [sqlite3_free()] directly. Only
2400 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2402 ** The sqlite3_get_table() interface is implemented as a wrapper around
2403 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2404 ** to any internal data structures of SQLite. It uses only the public
2405 ** interface defined here. As a consequence, errors that occur in the
2406 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2407 ** reflected in subsequent calls to [sqlite3_errcode()] or
2408 ** [sqlite3_errmsg()].
2410 SQLITE_API int sqlite3_get_table(
2411 sqlite3 *db, /* An open database */
2412 const char *zSql, /* SQL to be evaluated */
2413 char ***pazResult, /* Results of the query */
2414 int *pnRow, /* Number of result rows written here */
2415 int *pnColumn, /* Number of result columns written here */
2416 char **pzErrmsg /* Error msg written here */
2418 SQLITE_API void sqlite3_free_table(char **result);
2421 ** CAPI3REF: Formatted String Printing Functions
2423 ** These routines are work-alikes of the "printf()" family of functions
2424 ** from the standard C library.
2425 ** These routines understand most of the common K&R formatting options,
2426 ** plus some additional non-standard formats, detailed below.
2427 ** Note that some of the more obscure formatting options from recent
2428 ** C-library standards are omitted from this implementation.
2430 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2431 ** results into memory obtained from [sqlite3_malloc()].
2432 ** The strings returned by these two routines should be
2433 ** released by [sqlite3_free()]. ^Both routines return a
2434 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2435 ** memory to hold the resulting string.
2437 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2438 ** the standard C library. The result is written into the
2439 ** buffer supplied as the second parameter whose size is given by
2440 ** the first parameter. Note that the order of the
2441 ** first two parameters is reversed from snprintf().)^ This is an
2442 ** historical accident that cannot be fixed without breaking
2443 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2444 ** returns a pointer to its buffer instead of the number of
2445 ** characters actually written into the buffer.)^ We admit that
2446 ** the number of characters written would be a more useful return
2447 ** value but we cannot change the implementation of sqlite3_snprintf()
2448 ** now without breaking compatibility.
2450 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2451 ** guarantees that the buffer is always zero-terminated. ^The first
2452 ** parameter "n" is the total size of the buffer, including space for
2453 ** the zero terminator. So the longest string that can be completely
2454 ** written will be n-1 characters.
2456 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2458 ** These routines all implement some additional formatting
2459 ** options that are useful for constructing SQL statements.
2460 ** All of the usual printf() formatting options apply. In addition, there
2461 ** is are "%q", "%Q", "%w" and "%z" options.
2463 ** ^(The %q option works like %s in that it substitutes a nul-terminated
2464 ** string from the argument list. But %q also doubles every '\'' character.
2465 ** %q is designed for use inside a string literal.)^ By doubling each '\''
2466 ** character it escapes that character and allows it to be inserted into
2469 ** For example, assume the string variable zText contains text as follows:
2471 ** <blockquote><pre>
2472 ** char *zText = "It's a happy day!";
2473 ** </pre></blockquote>
2475 ** One can use this text in an SQL statement as follows:
2477 ** <blockquote><pre>
2478 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2479 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2480 ** sqlite3_free(zSQL);
2481 ** </pre></blockquote>
2483 ** Because the %q format string is used, the '\'' character in zText
2484 ** is escaped and the SQL generated is as follows:
2486 ** <blockquote><pre>
2487 ** INSERT INTO table1 VALUES('It''s a happy day!')
2488 ** </pre></blockquote>
2490 ** This is correct. Had we used %s instead of %q, the generated SQL
2491 ** would have looked like this:
2493 ** <blockquote><pre>
2494 ** INSERT INTO table1 VALUES('It's a happy day!');
2495 ** </pre></blockquote>
2497 ** This second example is an SQL syntax error. As a general rule you should
2498 ** always use %q instead of %s when inserting text into a string literal.
2500 ** ^(The %Q option works like %q except it also adds single quotes around
2501 ** the outside of the total string. Additionally, if the parameter in the
2502 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2503 ** single quotes).)^ So, for example, one could say:
2505 ** <blockquote><pre>
2506 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2507 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2508 ** sqlite3_free(zSQL);
2509 ** </pre></blockquote>
2511 ** The code above will render a correct SQL statement in the zSQL
2512 ** variable even if the zText variable is a NULL pointer.
2514 ** ^(The "%w" formatting option is like "%q" except that it expects to
2515 ** be contained within double-quotes instead of single quotes, and it
2516 ** escapes the double-quote character instead of the single-quote
2517 ** character.)^ The "%w" formatting option is intended for safely inserting
2518 ** table and column names into a constructed SQL statement.
2520 ** ^(The "%z" formatting option works like "%s" but with the
2521 ** addition that after the string has been read and copied into
2522 ** the result, [sqlite3_free()] is called on the input string.)^
2524 SQLITE_API char *sqlite3_mprintf(const char*,...);
2525 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2526 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2527 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2530 ** CAPI3REF: Memory Allocation Subsystem
2532 ** The SQLite core uses these three routines for all of its own
2533 ** internal memory allocation needs. "Core" in the previous sentence
2534 ** does not include operating-system specific VFS implementation. The
2535 ** Windows VFS uses native malloc() and free() for some operations.
2537 ** ^The sqlite3_malloc() routine returns a pointer to a block
2538 ** of memory at least N bytes in length, where N is the parameter.
2539 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2540 ** memory, it returns a NULL pointer. ^If the parameter N to
2541 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2544 ** ^The sqlite3_malloc64(N) routine works just like
2545 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2546 ** of a signed 32-bit integer.
2548 ** ^Calling sqlite3_free() with a pointer previously returned
2549 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2550 ** that it might be reused. ^The sqlite3_free() routine is
2551 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2552 ** to sqlite3_free() is harmless. After being freed, memory
2553 ** should neither be read nor written. Even reading previously freed
2554 ** memory might result in a segmentation fault or other severe error.
2555 ** Memory corruption, a segmentation fault, or other severe error
2556 ** might result if sqlite3_free() is called with a non-NULL pointer that
2557 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2559 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
2560 ** prior memory allocation X to be at least N bytes.
2561 ** ^If the X parameter to sqlite3_realloc(X,N)
2562 ** is a NULL pointer then its behavior is identical to calling
2563 ** sqlite3_malloc(N).
2564 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2565 ** negative then the behavior is exactly the same as calling
2567 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2568 ** of at least N bytes in size or NULL if insufficient memory is available.
2569 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2570 ** of the prior allocation are copied into the beginning of buffer returned
2571 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
2572 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2573 ** prior allocation is not freed.
2575 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
2576 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2577 ** of a 32-bit signed integer.
2579 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2580 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2581 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2582 ** ^The value returned by sqlite3_msize(X) might be larger than the number
2583 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
2584 ** sqlite3_msize(X) returns zero. If X points to something that is not
2585 ** the beginning of memory allocation, or if it points to a formerly
2586 ** valid memory allocation that has now been freed, then the behavior
2587 ** of sqlite3_msize(X) is undefined and possibly harmful.
2589 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2590 ** sqlite3_malloc64(), and sqlite3_realloc64()
2591 ** is always aligned to at least an 8 byte boundary, or to a
2592 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2595 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2596 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2597 ** implementation of these routines to be omitted. That capability
2598 ** is no longer provided. Only built-in memory allocators can be used.
2600 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2601 ** the system malloc() and free() directly when converting
2602 ** filenames between the UTF-8 encoding used by SQLite
2603 ** and whatever filename encoding is used by the particular Windows
2604 ** installation. Memory allocation errors were detected, but
2605 ** they were reported back as [SQLITE_CANTOPEN] or
2606 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2608 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2609 ** must be either NULL or else pointers obtained from a prior
2610 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2611 ** not yet been released.
2613 ** The application must not read or write any part of
2614 ** a block of memory after it has been released using
2615 ** [sqlite3_free()] or [sqlite3_realloc()].
2617 SQLITE_API void *sqlite3_malloc(int);
2618 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2619 SQLITE_API void *sqlite3_realloc(void*, int);
2620 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2621 SQLITE_API void sqlite3_free(void*);
2622 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2625 ** CAPI3REF: Memory Allocator Statistics
2627 ** SQLite provides these two interfaces for reporting on the status
2628 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2629 ** routines, which form the built-in memory allocation subsystem.
2631 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2632 ** of memory currently outstanding (malloced but not freed).
2633 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2634 ** value of [sqlite3_memory_used()] since the high-water mark
2635 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2636 ** [sqlite3_memory_highwater()] include any overhead
2637 ** added by SQLite in its implementation of [sqlite3_malloc()],
2638 ** but not overhead added by the any underlying system library
2639 ** routines that [sqlite3_malloc()] may call.
2641 ** ^The memory high-water mark is reset to the current value of
2642 ** [sqlite3_memory_used()] if and only if the parameter to
2643 ** [sqlite3_memory_highwater()] is true. ^The value returned
2644 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2645 ** prior to the reset.
2647 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2648 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2651 ** CAPI3REF: Pseudo-Random Number Generator
2653 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2654 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2655 ** already uses the largest possible [ROWID]. The PRNG is also used for
2656 ** the build-in random() and randomblob() SQL functions. This interface allows
2657 ** applications to access the same PRNG for other purposes.
2659 ** ^A call to this routine stores N bytes of randomness into buffer P.
2660 ** ^The P parameter can be a NULL pointer.
2662 ** ^If this routine has not been previously called or if the previous
2663 ** call had N less than one or a NULL pointer for P, then the PRNG is
2664 ** seeded using randomness obtained from the xRandomness method of
2665 ** the default [sqlite3_vfs] object.
2666 ** ^If the previous call to this routine had an N of 1 or more and a
2667 ** non-NULL P then the pseudo-randomness is generated
2668 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2671 SQLITE_API void sqlite3_randomness(int N, void *P);
2674 ** CAPI3REF: Compile-Time Authorization Callbacks
2676 ** KEYWORDS: {authorizer callback}
2678 ** ^This routine registers an authorizer callback with a particular
2679 ** [database connection], supplied in the first argument.
2680 ** ^The authorizer callback is invoked as SQL statements are being compiled
2681 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2682 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2683 ** points during the compilation process, as logic is being created
2684 ** to perform various actions, the authorizer callback is invoked to
2685 ** see if those actions are allowed. ^The authorizer callback should
2686 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2687 ** specific action but allow the SQL statement to continue to be
2688 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2689 ** rejected with an error. ^If the authorizer callback returns
2690 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2691 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2692 ** the authorizer will fail with an error message.
2694 ** When the callback returns [SQLITE_OK], that means the operation
2695 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2696 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2697 ** authorizer will fail with an error message explaining that
2698 ** access is denied.
2700 ** ^The first parameter to the authorizer callback is a copy of the third
2701 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2702 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2703 ** the particular action to be authorized. ^The third through sixth parameters
2704 ** to the callback are either NULL pointers or zero-terminated strings
2705 ** that contain additional details about the action to be authorized.
2706 ** Applications must always be prepared to encounter a NULL pointer in any
2707 ** of the third through the sixth parameters of the authorization callback.
2709 ** ^If the action code is [SQLITE_READ]
2710 ** and the callback returns [SQLITE_IGNORE] then the
2711 ** [prepared statement] statement is constructed to substitute
2712 ** a NULL value in place of the table column that would have
2713 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2714 ** return can be used to deny an untrusted user access to individual
2715 ** columns of a table.
2716 ** ^When a table is referenced by a [SELECT] but no column values are
2717 ** extracted from that table (for example in a query like
2718 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2719 ** is invoked once for that table with a column name that is an empty string.
2720 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2721 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2722 ** [truncate optimization] is disabled and all rows are deleted individually.
2724 ** An authorizer is used when [sqlite3_prepare | preparing]
2725 ** SQL statements from an untrusted source, to ensure that the SQL statements
2726 ** do not try to access data they are not allowed to see, or that they do not
2727 ** try to execute malicious statements that damage the database. For
2728 ** example, an application may allow a user to enter arbitrary
2729 ** SQL queries for evaluation by a database. But the application does
2730 ** not want the user to be able to make arbitrary changes to the
2731 ** database. An authorizer could then be put in place while the
2732 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2733 ** disallows everything except [SELECT] statements.
2735 ** Applications that need to process SQL from untrusted sources
2736 ** might also consider lowering resource limits using [sqlite3_limit()]
2737 ** and limiting database size using the [max_page_count] [PRAGMA]
2738 ** in addition to using an authorizer.
2740 ** ^(Only a single authorizer can be in place on a database connection
2741 ** at a time. Each call to sqlite3_set_authorizer overrides the
2742 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2743 ** The authorizer is disabled by default.
2745 ** The authorizer callback must not do anything that will modify
2746 ** the database connection that invoked the authorizer callback.
2747 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2748 ** database connections for the meaning of "modify" in this paragraph.
2750 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2751 ** statement might be re-prepared during [sqlite3_step()] due to a
2752 ** schema change. Hence, the application should ensure that the
2753 ** correct authorizer callback remains in place during the [sqlite3_step()].
2755 ** ^Note that the authorizer callback is invoked only during
2756 ** [sqlite3_prepare()] or its variants. Authorization is not
2757 ** performed during statement evaluation in [sqlite3_step()], unless
2758 ** as stated in the previous paragraph, sqlite3_step() invokes
2759 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2761 SQLITE_API int sqlite3_set_authorizer(
2763 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2768 ** CAPI3REF: Authorizer Return Codes
2770 ** The [sqlite3_set_authorizer | authorizer callback function] must
2771 ** return either [SQLITE_OK] or one of these two constants in order
2772 ** to signal SQLite whether or not the action is permitted. See the
2773 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2776 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2777 ** returned from the [sqlite3_vtab_on_conflict()] interface.
2779 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2780 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2783 ** CAPI3REF: Authorizer Action Codes
2785 ** The [sqlite3_set_authorizer()] interface registers a callback function
2786 ** that is invoked to authorize certain SQL statement actions. The
2787 ** second parameter to the callback is an integer code that specifies
2788 ** what action is being authorized. These are the integer action codes that
2789 ** the authorizer callback may be passed.
2791 ** These action code values signify what kind of operation is to be
2792 ** authorized. The 3rd and 4th parameters to the authorization
2793 ** callback function will be parameters or NULL depending on which of these
2794 ** codes is used as the second parameter. ^(The 5th parameter to the
2795 ** authorizer callback is the name of the database ("main", "temp",
2796 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2797 ** is the name of the inner-most trigger or view that is responsible for
2798 ** the access attempt or NULL if this access attempt is directly from
2799 ** top-level SQL code.
2801 /******************************************* 3rd ************ 4th ***********/
2802 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2803 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2804 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2805 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2806 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2807 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2808 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2809 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2810 #define SQLITE_DELETE 9 /* Table Name NULL */
2811 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2812 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2813 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2814 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2815 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2816 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2817 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2818 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2819 #define SQLITE_INSERT 18 /* Table Name NULL */
2820 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2821 #define SQLITE_READ 20 /* Table Name Column Name */
2822 #define SQLITE_SELECT 21 /* NULL NULL */
2823 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2824 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2825 #define SQLITE_ATTACH 24 /* Filename NULL */
2826 #define SQLITE_DETACH 25 /* Database Name NULL */
2827 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2828 #define SQLITE_REINDEX 27 /* Index Name NULL */
2829 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2830 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2831 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2832 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2833 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2834 #define SQLITE_COPY 0 /* No longer used */
2835 #define SQLITE_RECURSIVE 33 /* NULL NULL */
2838 ** CAPI3REF: Tracing And Profiling Functions
2841 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2842 ** instead of the routines described here.
2844 ** These routines register callback functions that can be used for
2845 ** tracing and profiling the execution of SQL statements.
2847 ** ^The callback function registered by sqlite3_trace() is invoked at
2848 ** various times when an SQL statement is being run by [sqlite3_step()].
2849 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2850 ** SQL statement text as the statement first begins executing.
2851 ** ^(Additional sqlite3_trace() callbacks might occur
2852 ** as each triggered subprogram is entered. The callbacks for triggers
2853 ** contain a UTF-8 SQL comment that identifies the trigger.)^
2855 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2856 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
2858 ** ^The callback function registered by sqlite3_profile() is invoked
2859 ** as each SQL statement finishes. ^The profile callback contains
2860 ** the original statement text and an estimate of wall-clock time
2861 ** of how long that statement took to run. ^The profile callback
2862 ** time is in units of nanoseconds, however the current implementation
2863 ** is only capable of millisecond resolution so the six least significant
2864 ** digits in the time are meaningless. Future versions of SQLite
2865 ** might provide greater resolution on the profiler callback. The
2866 ** sqlite3_profile() function is considered experimental and is
2867 ** subject to change in future versions of SQLite.
2869 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
2870 void(*xTrace)(void*,const char*), void*);
2871 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
2872 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2875 ** CAPI3REF: SQL Trace Event Codes
2876 ** KEYWORDS: SQLITE_TRACE
2878 ** These constants identify classes of events that can be monitored
2879 ** using the [sqlite3_trace_v2()] tracing logic. The third argument
2880 ** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of
2881 ** the following constants. ^The first argument to the trace callback
2882 ** is one of the following constants.
2884 ** New tracing constants may be added in future releases.
2886 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
2887 ** ^The T argument is one of the integer type codes above.
2888 ** ^The C argument is a copy of the context pointer passed in as the
2889 ** fourth argument to [sqlite3_trace_v2()].
2890 ** The P and X arguments are pointers whose meanings depend on T.
2893 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
2894 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
2895 ** first begins running and possibly at other times during the
2896 ** execution of the prepared statement, such as at the start of each
2897 ** trigger subprogram. ^The P argument is a pointer to the
2898 ** [prepared statement]. ^The X argument is a pointer to a string which
2899 ** is the unexpanded SQL text of the prepared statement or an SQL comment
2900 ** that indicates the invocation of a trigger. ^The callback can compute
2901 ** the same text that would have been returned by the legacy [sqlite3_trace()]
2902 ** interface by using the X argument when X begins with "--" and invoking
2903 ** [sqlite3_expanded_sql(P)] otherwise.
2905 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
2906 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
2907 ** information as is provided by the [sqlite3_profile()] callback.
2908 ** ^The P argument is a pointer to the [prepared statement] and the
2909 ** X argument points to a 64-bit integer which is the estimated of
2910 ** the number of nanosecond that the prepared statement took to run.
2911 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
2913 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
2914 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
2915 ** statement generates a single row of result.
2916 ** ^The P argument is a pointer to the [prepared statement] and the
2917 ** X argument is unused.
2919 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
2920 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
2921 ** connection closes.
2922 ** ^The P argument is a pointer to the [database connection] object
2923 ** and the X argument is unused.
2926 #define SQLITE_TRACE_STMT 0x01
2927 #define SQLITE_TRACE_PROFILE 0x02
2928 #define SQLITE_TRACE_ROW 0x04
2929 #define SQLITE_TRACE_CLOSE 0x08
2932 ** CAPI3REF: SQL Trace Hook
2935 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
2936 ** function X against [database connection] D, using property mask M
2937 ** and context pointer P. ^If the X callback is
2938 ** NULL or if the M mask is zero, then tracing is disabled. The
2939 ** M argument should be the bitwise OR-ed combination of
2940 ** zero or more [SQLITE_TRACE] constants.
2942 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
2943 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
2945 ** ^The X callback is invoked whenever any of the events identified by
2946 ** mask M occur. ^The integer return value from the callback is currently
2947 ** ignored, though this may change in future releases. Callback
2948 ** implementations should return zero to ensure future compatibility.
2950 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
2951 ** ^The T argument is one of the [SQLITE_TRACE]
2952 ** constants to indicate why the callback was invoked.
2953 ** ^The C argument is a copy of the context pointer.
2954 ** The P and X arguments are pointers whose meanings depend on T.
2956 ** The sqlite3_trace_v2() interface is intended to replace the legacy
2957 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
2960 SQLITE_API int sqlite3_trace_v2(
2963 int(*xCallback)(unsigned,void*,void*,void*),
2968 ** CAPI3REF: Query Progress Callbacks
2971 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2972 ** function X to be invoked periodically during long running calls to
2973 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2974 ** database connection D. An example use for this
2975 ** interface is to keep a GUI updated during a large query.
2977 ** ^The parameter P is passed through as the only parameter to the
2978 ** callback function X. ^The parameter N is the approximate number of
2979 ** [virtual machine instructions] that are evaluated between successive
2980 ** invocations of the callback X. ^If N is less than one then the progress
2981 ** handler is disabled.
2983 ** ^Only a single progress handler may be defined at one time per
2984 ** [database connection]; setting a new progress handler cancels the
2985 ** old one. ^Setting parameter X to NULL disables the progress handler.
2986 ** ^The progress handler is also disabled by setting N to a value less
2989 ** ^If the progress callback returns non-zero, the operation is
2990 ** interrupted. This feature can be used to implement a
2991 ** "Cancel" button on a GUI progress dialog box.
2993 ** The progress handler callback must not do anything that will modify
2994 ** the database connection that invoked the progress handler.
2995 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2996 ** database connections for the meaning of "modify" in this paragraph.
2999 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3002 ** CAPI3REF: Opening A New Database Connection
3003 ** CONSTRUCTOR: sqlite3
3005 ** ^These routines open an SQLite database file as specified by the
3006 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3007 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3008 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3009 ** returned in *ppDb, even if an error occurs. The only exception is that
3010 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3011 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3012 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3013 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3014 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3015 ** an English language description of the error following a failure of any
3016 ** of the sqlite3_open() routines.
3018 ** ^The default encoding will be UTF-8 for databases created using
3019 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3020 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3022 ** Whether or not an error occurs when it is opened, resources
3023 ** associated with the [database connection] handle should be released by
3024 ** passing it to [sqlite3_close()] when it is no longer required.
3026 ** The sqlite3_open_v2() interface works like sqlite3_open()
3027 ** except that it accepts two additional parameters for additional control
3028 ** over the new database connection. ^(The flags parameter to
3029 ** sqlite3_open_v2() can take one of
3030 ** the following three values, optionally combined with the
3031 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3032 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3035 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3036 ** <dd>The database is opened in read-only mode. If the database does not
3037 ** already exist, an error is returned.</dd>)^
3039 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3040 ** <dd>The database is opened for reading and writing if possible, or reading
3041 ** only if the file is write protected by the operating system. In either
3042 ** case the database must already exist, otherwise an error is returned.</dd>)^
3044 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3045 ** <dd>The database is opened for reading and writing, and is created if
3046 ** it does not already exist. This is the behavior that is always used for
3047 ** sqlite3_open() and sqlite3_open16().</dd>)^
3050 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3051 ** combinations shown above optionally combined with other
3052 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3053 ** then the behavior is undefined.
3055 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3056 ** opens in the multi-thread [threading mode] as long as the single-thread
3057 ** mode has not been set at compile-time or start-time. ^If the
3058 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3059 ** in the serialized [threading mode] unless single-thread was
3060 ** previously selected at compile-time or start-time.
3061 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3062 ** eligible to use [shared cache mode], regardless of whether or not shared
3063 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3064 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3065 ** participate in [shared cache mode] even if it is enabled.
3067 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3068 ** [sqlite3_vfs] object that defines the operating system interface that
3069 ** the new database connection should use. ^If the fourth parameter is
3070 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3072 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3073 ** is created for the connection. ^This in-memory database will vanish when
3074 ** the database connection is closed. Future versions of SQLite might
3075 ** make use of additional special filenames that begin with the ":" character.
3076 ** It is recommended that when a database filename actually does begin with
3077 ** a ":" character you should prefix the filename with a pathname such as
3078 ** "./" to avoid ambiguity.
3080 ** ^If the filename is an empty string, then a private, temporary
3081 ** on-disk database will be created. ^This private database will be
3082 ** automatically deleted as soon as the database connection is closed.
3084 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3086 ** ^If [URI filename] interpretation is enabled, and the filename argument
3087 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3088 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3089 ** set in the fourth argument to sqlite3_open_v2(), or if it has
3090 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3091 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3092 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
3093 ** by default, but future releases of SQLite might enable URI filename
3094 ** interpretation by default. See "[URI filenames]" for additional
3097 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3098 ** authority, then it must be either an empty string or the string
3099 ** "localhost". ^If the authority is not an empty string or "localhost", an
3100 ** error is returned to the caller. ^The fragment component of a URI, if
3101 ** present, is ignored.
3103 ** ^SQLite uses the path component of the URI as the name of the disk file
3104 ** which contains the database. ^If the path begins with a '/' character,
3105 ** then it is interpreted as an absolute path. ^If the path does not begin
3106 ** with a '/' (meaning that the authority section is omitted from the URI)
3107 ** then the path is interpreted as a relative path.
3108 ** ^(On windows, the first component of an absolute path
3109 ** is a drive specification (e.g. "C:").)^
3111 ** [[core URI query parameters]]
3112 ** The query component of a URI may contain parameters that are interpreted
3113 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3114 ** SQLite and its built-in [VFSes] interpret the
3115 ** following query parameters:
3118 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3119 ** a VFS object that provides the operating system interface that should
3120 ** be used to access the database file on disk. ^If this option is set to
3121 ** an empty string the default VFS object is used. ^Specifying an unknown
3122 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3123 ** present, then the VFS specified by the option takes precedence over
3124 ** the value passed as the fourth parameter to sqlite3_open_v2().
3126 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3127 ** "rwc", or "memory". Attempting to set it to any other value is
3129 ** ^If "ro" is specified, then the database is opened for read-only
3130 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3131 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3132 ** "rw", then the database is opened for read-write (but not create)
3133 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3134 ** been set. ^Value "rwc" is equivalent to setting both
3135 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3136 ** set to "memory" then a pure [in-memory database] that never reads
3137 ** or writes from disk is used. ^It is an error to specify a value for
3138 ** the mode parameter that is less restrictive than that specified by
3139 ** the flags passed in the third parameter to sqlite3_open_v2().
3141 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3142 ** "private". ^Setting it to "shared" is equivalent to setting the
3143 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3144 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3145 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3146 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3147 ** a URI filename, its value overrides any behavior requested by setting
3148 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3150 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3151 ** [powersafe overwrite] property does or does not apply to the
3152 ** storage media on which the database file resides.
3154 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3155 ** which if set disables file locking in rollback journal modes. This
3156 ** is useful for accessing a database on a filesystem that does not
3157 ** support locking. Caution: Database corruption might result if two
3158 ** or more processes write to the same database and any one of those
3159 ** processes uses nolock=1.
3161 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3162 ** parameter that indicates that the database file is stored on
3163 ** read-only media. ^When immutable is set, SQLite assumes that the
3164 ** database file cannot be changed, even by a process with higher
3165 ** privilege, and so the database is opened read-only and all locking
3166 ** and change detection is disabled. Caution: Setting the immutable
3167 ** property on a database file that does in fact change can result
3168 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3169 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3173 ** ^Specifying an unknown parameter in the query component of a URI is not an
3174 ** error. Future versions of SQLite might understand additional query
3175 ** parameters. See "[query parameters with special meaning to SQLite]" for
3176 ** additional information.
3178 ** [[URI filename examples]] <h3>URI filename examples</h3>
3180 ** <table border="1" align=center cellpadding=5>
3181 ** <tr><th> URI filenames <th> Results
3182 ** <tr><td> file:data.db <td>
3183 ** Open the file "data.db" in the current directory.
3184 ** <tr><td> file:/home/fred/data.db<br>
3185 ** file:///home/fred/data.db <br>
3186 ** file://localhost/home/fred/data.db <br> <td>
3187 ** Open the database file "/home/fred/data.db".
3188 ** <tr><td> file://darkstar/home/fred/data.db <td>
3189 ** An error. "darkstar" is not a recognized authority.
3190 ** <tr><td style="white-space:nowrap">
3191 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3192 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3193 ** C:. Note that the %20 escaping in this example is not strictly
3194 ** necessary - space characters can be used literally
3195 ** in URI filenames.
3196 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3197 ** Open file "data.db" in the current directory for read-only access.
3198 ** Regardless of whether or not shared-cache mode is enabled by
3199 ** default, use a private cache.
3200 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3201 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3202 ** that uses dot-files in place of posix advisory locking.
3203 ** <tr><td> file:data.db?mode=readonly <td>
3204 ** An error. "readonly" is not a valid option for the "mode" parameter.
3207 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3208 ** query components of a URI. A hexadecimal escape sequence consists of a
3209 ** percent sign - "%" - followed by exactly two hexadecimal digits
3210 ** specifying an octet value. ^Before the path or query components of a
3211 ** URI filename are interpreted, they are encoded using UTF-8 and all
3212 ** hexadecimal escape sequences replaced by a single byte containing the
3213 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3214 ** the results are undefined.
3216 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3217 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3218 ** codepage is currently defined. Filenames containing international
3219 ** characters must be converted to UTF-8 prior to passing them into
3220 ** sqlite3_open() or sqlite3_open_v2().
3222 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3223 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3224 ** features that require the use of temporary files may fail.
3226 ** See also: [sqlite3_temp_directory]
3228 SQLITE_API int sqlite3_open(
3229 const char *filename, /* Database filename (UTF-8) */
3230 sqlite3 **ppDb /* OUT: SQLite db handle */
3232 SQLITE_API int sqlite3_open16(
3233 const void *filename, /* Database filename (UTF-16) */
3234 sqlite3 **ppDb /* OUT: SQLite db handle */
3236 SQLITE_API int sqlite3_open_v2(
3237 const char *filename, /* Database filename (UTF-8) */
3238 sqlite3 **ppDb, /* OUT: SQLite db handle */
3239 int flags, /* Flags */
3240 const char *zVfs /* Name of VFS module to use */
3244 ** CAPI3REF: Obtain Values For URI Parameters
3246 ** These are utility routines, useful to VFS implementations, that check
3247 ** to see if a database file was a URI that contained a specific query
3248 ** parameter, and if so obtains the value of that query parameter.
3250 ** If F is the database filename pointer passed into the xOpen() method of
3251 ** a VFS implementation when the flags parameter to xOpen() has one or
3252 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3253 ** P is the name of the query parameter, then
3254 ** sqlite3_uri_parameter(F,P) returns the value of the P
3255 ** parameter if it exists or a NULL pointer if P does not appear as a
3256 ** query parameter on F. If P is a query parameter of F
3257 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3258 ** a pointer to an empty string.
3260 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3261 ** parameter and returns true (1) or false (0) according to the value
3262 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3263 ** value of query parameter P is one of "yes", "true", or "on" in any
3264 ** case or if the value begins with a non-zero number. The
3265 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3266 ** query parameter P is one of "no", "false", or "off" in any case or
3267 ** if the value begins with a numeric zero. If P is not a query
3268 ** parameter on F or if the value of P is does not match any of the
3269 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3271 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3272 ** 64-bit signed integer and returns that integer, or D if P does not
3273 ** exist. If the value of P is something other than an integer, then
3274 ** zero is returned.
3276 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3277 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3278 ** is not a database file pathname pointer that SQLite passed into the xOpen
3279 ** VFS method, then the behavior of this routine is undefined and probably
3282 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3283 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3284 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3288 ** CAPI3REF: Error Codes And Messages
3291 ** ^If the most recent sqlite3_* API call associated with
3292 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3293 ** returns the numeric [result code] or [extended result code] for that
3295 ** If the most recent API call was successful,
3296 ** then the return value from sqlite3_errcode() is undefined.
3297 ** ^The sqlite3_extended_errcode()
3298 ** interface is the same except that it always returns the
3299 ** [extended result code] even when extended result codes are
3302 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3303 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
3304 ** ^(Memory to hold the error message string is managed internally.
3305 ** The application does not need to worry about freeing the result.
3306 ** However, the error string might be overwritten or deallocated by
3307 ** subsequent calls to other SQLite interface functions.)^
3309 ** ^The sqlite3_errstr() interface returns the English-language text
3310 ** that describes the [result code], as UTF-8.
3311 ** ^(Memory to hold the error message string is managed internally
3312 ** and must not be freed by the application)^.
3314 ** When the serialized [threading mode] is in use, it might be the
3315 ** case that a second error occurs on a separate thread in between
3316 ** the time of the first error and the call to these interfaces.
3317 ** When that happens, the second error will be reported since these
3318 ** interfaces always report the most recent result. To avoid
3319 ** this, each thread can obtain exclusive use of the [database connection] D
3320 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3321 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3322 ** all calls to the interfaces listed here are completed.
3324 ** If an interface fails with SQLITE_MISUSE, that means the interface
3325 ** was invoked incorrectly by the application. In that case, the
3326 ** error code and message may or may not be set.
3328 SQLITE_API int sqlite3_errcode(sqlite3 *db);
3329 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3330 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3331 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3332 SQLITE_API const char *sqlite3_errstr(int);
3335 ** CAPI3REF: Prepared Statement Object
3336 ** KEYWORDS: {prepared statement} {prepared statements}
3338 ** An instance of this object represents a single SQL statement that
3339 ** has been compiled into binary form and is ready to be evaluated.
3341 ** Think of each SQL statement as a separate computer program. The
3342 ** original SQL text is source code. A prepared statement object
3343 ** is the compiled object code. All SQL must be converted into a
3344 ** prepared statement before it can be run.
3346 ** The life-cycle of a prepared statement object usually goes like this:
3349 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3350 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
3352 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3353 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3354 ** to step 2. Do this zero or more times.
3355 ** <li> Destroy the object using [sqlite3_finalize()].
3358 typedef struct sqlite3_stmt sqlite3_stmt;
3361 ** CAPI3REF: Run-time Limits
3364 ** ^(This interface allows the size of various constructs to be limited
3365 ** on a connection by connection basis. The first parameter is the
3366 ** [database connection] whose limit is to be set or queried. The
3367 ** second parameter is one of the [limit categories] that define a
3368 ** class of constructs to be size limited. The third parameter is the
3369 ** new limit for that construct.)^
3371 ** ^If the new limit is a negative number, the limit is unchanged.
3372 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3373 ** [limits | hard upper bound]
3374 ** set at compile-time by a C preprocessor macro called
3375 ** [limits | SQLITE_MAX_<i>NAME</i>].
3376 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3377 ** ^Attempts to increase a limit above its hard upper bound are
3378 ** silently truncated to the hard upper bound.
3380 ** ^Regardless of whether or not the limit was changed, the
3381 ** [sqlite3_limit()] interface returns the prior value of the limit.
3382 ** ^Hence, to find the current value of a limit without changing it,
3383 ** simply invoke this interface with the third parameter set to -1.
3385 ** Run-time limits are intended for use in applications that manage
3386 ** both their own internal database and also databases that are controlled
3387 ** by untrusted external sources. An example application might be a
3388 ** web browser that has its own databases for storing history and
3389 ** separate databases controlled by JavaScript applications downloaded
3390 ** off the Internet. The internal databases can be given the
3391 ** large, default limits. Databases managed by external sources can
3392 ** be given much smaller limits designed to prevent a denial of service
3393 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3394 ** interface to further control untrusted SQL. The size of the database
3395 ** created by an untrusted script can be contained using the
3396 ** [max_page_count] [PRAGMA].
3398 ** New run-time limit categories may be added in future releases.
3400 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3403 ** CAPI3REF: Run-Time Limit Categories
3404 ** KEYWORDS: {limit category} {*limit categories}
3406 ** These constants define various performance limits
3407 ** that can be lowered at run-time using [sqlite3_limit()].
3408 ** The synopsis of the meanings of the various limits is shown below.
3409 ** Additional information is available at [limits | Limits in SQLite].
3412 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3413 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3415 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3416 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3418 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3419 ** <dd>The maximum number of columns in a table definition or in the
3420 ** result set of a [SELECT] or the maximum number of columns in an index
3421 ** or in an ORDER BY or GROUP BY clause.</dd>)^
3423 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3424 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3426 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3427 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3429 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3430 ** <dd>The maximum number of instructions in a virtual machine program
3431 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3432 ** the equivalent tries to allocate space for more than this many opcodes
3433 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3435 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3436 ** <dd>The maximum number of arguments on a function.</dd>)^
3438 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3439 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3441 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3442 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3443 ** <dd>The maximum length of the pattern argument to the [LIKE] or
3444 ** [GLOB] operators.</dd>)^
3446 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3447 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3448 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3450 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3451 ** <dd>The maximum depth of recursion for triggers.</dd>)^
3453 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3454 ** <dd>The maximum number of auxiliary worker threads that a single
3455 ** [prepared statement] may start.</dd>)^
3458 #define SQLITE_LIMIT_LENGTH 0
3459 #define SQLITE_LIMIT_SQL_LENGTH 1
3460 #define SQLITE_LIMIT_COLUMN 2
3461 #define SQLITE_LIMIT_EXPR_DEPTH 3
3462 #define SQLITE_LIMIT_COMPOUND_SELECT 4
3463 #define SQLITE_LIMIT_VDBE_OP 5
3464 #define SQLITE_LIMIT_FUNCTION_ARG 6
3465 #define SQLITE_LIMIT_ATTACHED 7
3466 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3467 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
3468 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
3469 #define SQLITE_LIMIT_WORKER_THREADS 11
3473 ** CAPI3REF: Compiling An SQL Statement
3474 ** KEYWORDS: {SQL statement compiler}
3476 ** CONSTRUCTOR: sqlite3_stmt
3478 ** To execute an SQL query, it must first be compiled into a byte-code
3479 ** program using one of these routines.
3481 ** The first argument, "db", is a [database connection] obtained from a
3482 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3483 ** [sqlite3_open16()]. The database connection must not have been closed.
3485 ** The second argument, "zSql", is the statement to be compiled, encoded
3486 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
3487 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3490 ** ^If the nByte argument is negative, then zSql is read up to the
3491 ** first zero terminator. ^If nByte is positive, then it is the
3492 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
3493 ** statement is generated.
3494 ** If the caller knows that the supplied string is nul-terminated, then
3495 ** there is a small performance advantage to passing an nByte parameter that
3496 ** is the number of bytes in the input string <i>including</i>
3497 ** the nul-terminator.
3499 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3500 ** past the end of the first SQL statement in zSql. These routines only
3501 ** compile the first statement in zSql, so *pzTail is left pointing to
3502 ** what remains uncompiled.
3504 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3505 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3506 ** to NULL. ^If the input text contains no SQL (if the input is an empty
3507 ** string or a comment) then *ppStmt is set to NULL.
3508 ** The calling procedure is responsible for deleting the compiled
3509 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
3510 ** ppStmt may not be NULL.
3512 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3513 ** otherwise an [error code] is returned.
3515 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3516 ** recommended for all new programs. The two older interfaces are retained
3517 ** for backwards compatibility, but their use is discouraged.
3518 ** ^In the "v2" interfaces, the prepared statement
3519 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
3520 ** original SQL text. This causes the [sqlite3_step()] interface to
3521 ** behave differently in three ways:
3525 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3526 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
3527 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3528 ** retries will occur before sqlite3_step() gives up and returns an error.
3532 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3533 ** [error codes] or [extended error codes]. ^The legacy behavior was that
3534 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3535 ** and the application would have to make a second call to [sqlite3_reset()]
3536 ** in order to find the underlying cause of the problem. With the "v2" prepare
3537 ** interfaces, the underlying reason for the error is returned immediately.
3541 ** ^If the specific value bound to [parameter | host parameter] in the
3542 ** WHERE clause might influence the choice of query plan for a statement,
3543 ** then the statement will be automatically recompiled, as if there had been
3544 ** a schema change, on the first [sqlite3_step()] call following any change
3545 ** to the [sqlite3_bind_text | bindings] of that [parameter].
3546 ** ^The specific value of WHERE-clause [parameter] might influence the
3547 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
3548 ** or [GLOB] operator or if the parameter is compared to an indexed column
3549 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3553 SQLITE_API int sqlite3_prepare(
3554 sqlite3 *db, /* Database handle */
3555 const char *zSql, /* SQL statement, UTF-8 encoded */
3556 int nByte, /* Maximum length of zSql in bytes. */
3557 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3558 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3560 SQLITE_API int sqlite3_prepare_v2(
3561 sqlite3 *db, /* Database handle */
3562 const char *zSql, /* SQL statement, UTF-8 encoded */
3563 int nByte, /* Maximum length of zSql in bytes. */
3564 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3565 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3567 SQLITE_API int sqlite3_prepare16(
3568 sqlite3 *db, /* Database handle */
3569 const void *zSql, /* SQL statement, UTF-16 encoded */
3570 int nByte, /* Maximum length of zSql in bytes. */
3571 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3572 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3574 SQLITE_API int sqlite3_prepare16_v2(
3575 sqlite3 *db, /* Database handle */
3576 const void *zSql, /* SQL statement, UTF-16 encoded */
3577 int nByte, /* Maximum length of zSql in bytes. */
3578 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3579 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3583 ** CAPI3REF: Retrieving Statement SQL
3584 ** METHOD: sqlite3_stmt
3586 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3587 ** SQL text used to create [prepared statement] P if P was
3588 ** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3589 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3590 ** string containing the SQL text of prepared statement P with
3591 ** [bound parameters] expanded.
3593 ** ^(For example, if a prepared statement is created using the SQL
3594 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3595 ** and parameter :xyz is unbound, then sqlite3_sql() will return
3596 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3597 ** will return "SELECT 2345,NULL".)^
3599 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3600 ** is available to hold the result, or if the result would exceed the
3601 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3603 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3604 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3605 ** option causes sqlite3_expanded_sql() to always return NULL.
3607 ** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
3608 ** automatically freed when the prepared statement is finalized.
3609 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3610 ** is obtained from [sqlite3_malloc()] and must be free by the application
3611 ** by passing it to [sqlite3_free()].
3613 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3614 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3617 ** CAPI3REF: Determine If An SQL Statement Writes The Database
3618 ** METHOD: sqlite3_stmt
3620 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3621 ** and only if the [prepared statement] X makes no direct changes to
3622 ** the content of the database file.
3624 ** Note that [application-defined SQL functions] or
3625 ** [virtual tables] might change the database indirectly as a side effect.
3626 ** ^(For example, if an application defines a function "eval()" that
3627 ** calls [sqlite3_exec()], then the following SQL statement would
3628 ** change the database file through side-effects:
3630 ** <blockquote><pre>
3631 ** SELECT eval('DELETE FROM t1') FROM t2;
3632 ** </pre></blockquote>
3634 ** But because the [SELECT] statement does not change the database file
3635 ** directly, sqlite3_stmt_readonly() would still return true.)^
3637 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3638 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3639 ** since the statements themselves do not actually modify the database but
3640 ** rather they control the timing of when other statements modify the
3641 ** database. ^The [ATTACH] and [DETACH] statements also cause
3642 ** sqlite3_stmt_readonly() to return true since, while those statements
3643 ** change the configuration of a database connection, they do not make
3644 ** changes to the content of the database files on disk.
3645 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3646 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3647 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3648 ** sqlite3_stmt_readonly() returns false for those commands.
3650 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3653 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3654 ** METHOD: sqlite3_stmt
3656 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3657 ** [prepared statement] S has been stepped at least once using
3658 ** [sqlite3_step(S)] but has neither run to completion (returned
3659 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3660 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3661 ** interface returns false if S is a NULL pointer. If S is not a
3662 ** NULL pointer and is not a pointer to a valid [prepared statement]
3663 ** object, then the behavior is undefined and probably undesirable.
3665 ** This interface can be used in combination [sqlite3_next_stmt()]
3666 ** to locate all prepared statements associated with a database
3667 ** connection that are in need of being reset. This can be used,
3668 ** for example, in diagnostic routines to search for prepared
3669 ** statements that are holding a transaction open.
3671 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3674 ** CAPI3REF: Dynamically Typed Value Object
3675 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3677 ** SQLite uses the sqlite3_value object to represent all values
3678 ** that can be stored in a database table. SQLite uses dynamic typing
3679 ** for the values it stores. ^Values stored in sqlite3_value objects
3680 ** can be integers, floating point values, strings, BLOBs, or NULL.
3682 ** An sqlite3_value object may be either "protected" or "unprotected".
3683 ** Some interfaces require a protected sqlite3_value. Other interfaces
3684 ** will accept either a protected or an unprotected sqlite3_value.
3685 ** Every interface that accepts sqlite3_value arguments specifies
3686 ** whether or not it requires a protected sqlite3_value. The
3687 ** [sqlite3_value_dup()] interface can be used to construct a new
3688 ** protected sqlite3_value from an unprotected sqlite3_value.
3690 ** The terms "protected" and "unprotected" refer to whether or not
3691 ** a mutex is held. An internal mutex is held for a protected
3692 ** sqlite3_value object but no mutex is held for an unprotected
3693 ** sqlite3_value object. If SQLite is compiled to be single-threaded
3694 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3695 ** or if SQLite is run in one of reduced mutex modes
3696 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3697 ** then there is no distinction between protected and unprotected
3698 ** sqlite3_value objects and they can be used interchangeably. However,
3699 ** for maximum code portability it is recommended that applications
3700 ** still make the distinction between protected and unprotected
3701 ** sqlite3_value objects even when not strictly required.
3703 ** ^The sqlite3_value objects that are passed as parameters into the
3704 ** implementation of [application-defined SQL functions] are protected.
3705 ** ^The sqlite3_value object returned by
3706 ** [sqlite3_column_value()] is unprotected.
3707 ** Unprotected sqlite3_value objects may only be used with
3708 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
3709 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3710 ** interfaces require protected sqlite3_value objects.
3712 typedef struct sqlite3_value sqlite3_value;
3715 ** CAPI3REF: SQL Function Context Object
3717 ** The context in which an SQL function executes is stored in an
3718 ** sqlite3_context object. ^A pointer to an sqlite3_context object
3719 ** is always first parameter to [application-defined SQL functions].
3720 ** The application-defined SQL function implementation will pass this
3721 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3722 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3723 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3724 ** and/or [sqlite3_set_auxdata()].
3726 typedef struct sqlite3_context sqlite3_context;
3729 ** CAPI3REF: Binding Values To Prepared Statements
3730 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3731 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3732 ** METHOD: sqlite3_stmt
3734 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3735 ** literals may be replaced by a [parameter] that matches one of following
3746 ** In the templates above, NNN represents an integer literal,
3747 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3748 ** parameters (also called "host parameter names" or "SQL parameters")
3749 ** can be set using the sqlite3_bind_*() routines defined here.
3751 ** ^The first argument to the sqlite3_bind_*() routines is always
3752 ** a pointer to the [sqlite3_stmt] object returned from
3753 ** [sqlite3_prepare_v2()] or its variants.
3755 ** ^The second argument is the index of the SQL parameter to be set.
3756 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3757 ** SQL parameter is used more than once, second and subsequent
3758 ** occurrences have the same index as the first occurrence.
3759 ** ^The index for named parameters can be looked up using the
3760 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3761 ** for "?NNN" parameters is the value of NNN.
3762 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3763 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3765 ** ^The third argument is the value to bind to the parameter.
3766 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3767 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3768 ** is ignored and the end result is the same as sqlite3_bind_null().
3770 ** ^(In those routines that have a fourth argument, its value is the
3771 ** number of bytes in the parameter. To be clear: the value is the
3772 ** number of <u>bytes</u> in the value, not the number of characters.)^
3773 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3774 ** is negative, then the length of the string is
3775 ** the number of bytes up to the first zero terminator.
3776 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
3777 ** the behavior is undefined.
3778 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3779 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3780 ** that parameter must be the byte offset
3781 ** where the NUL terminator would occur assuming the string were NUL
3782 ** terminated. If any NUL characters occur at byte offsets less than
3783 ** the value of the fourth parameter then the resulting string value will
3784 ** contain embedded NULs. The result of expressions involving strings
3785 ** with embedded NULs is undefined.
3787 ** ^The fifth argument to the BLOB and string binding interfaces
3788 ** is a destructor used to dispose of the BLOB or
3789 ** string after SQLite has finished with it. ^The destructor is called
3790 ** to dispose of the BLOB or string even if the call to bind API fails.
3791 ** ^If the fifth argument is
3792 ** the special value [SQLITE_STATIC], then SQLite assumes that the
3793 ** information is in static, unmanaged space and does not need to be freed.
3794 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3795 ** SQLite makes its own private copy of the data immediately, before
3796 ** the sqlite3_bind_*() routine returns.
3798 ** ^The sixth argument to sqlite3_bind_text64() must be one of
3799 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
3800 ** to specify the encoding of the text in the third parameter. If
3801 ** the sixth argument to sqlite3_bind_text64() is not one of the
3802 ** allowed values shown above, or if the text encoding is different
3803 ** from the encoding specified by the sixth parameter, then the behavior
3806 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3807 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3808 ** (just an integer to hold its size) while it is being processed.
3809 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3810 ** content is later written using
3811 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3812 ** ^A negative value for the zeroblob results in a zero-length BLOB.
3814 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3815 ** for the [prepared statement] or with a prepared statement for which
3816 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3817 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3818 ** routine is passed a [prepared statement] that has been finalized, the
3819 ** result is undefined and probably harmful.
3821 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3822 ** ^Unbound parameters are interpreted as NULL.
3824 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3825 ** [error code] if anything goes wrong.
3826 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
3827 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
3828 ** [SQLITE_MAX_LENGTH].
3829 ** ^[SQLITE_RANGE] is returned if the parameter
3830 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3832 ** See also: [sqlite3_bind_parameter_count()],
3833 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3835 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3836 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
3838 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3839 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3840 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3841 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3842 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
3843 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3844 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
3845 void(*)(void*), unsigned char encoding);
3846 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3847 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3848 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
3851 ** CAPI3REF: Number Of SQL Parameters
3852 ** METHOD: sqlite3_stmt
3854 ** ^This routine can be used to find the number of [SQL parameters]
3855 ** in a [prepared statement]. SQL parameters are tokens of the
3856 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3857 ** placeholders for values that are [sqlite3_bind_blob | bound]
3858 ** to the parameters at a later time.
3860 ** ^(This routine actually returns the index of the largest (rightmost)
3861 ** parameter. For all forms except ?NNN, this will correspond to the
3862 ** number of unique parameters. If parameters of the ?NNN form are used,
3863 ** there may be gaps in the list.)^
3865 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3866 ** [sqlite3_bind_parameter_name()], and
3867 ** [sqlite3_bind_parameter_index()].
3869 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3872 ** CAPI3REF: Name Of A Host Parameter
3873 ** METHOD: sqlite3_stmt
3875 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3876 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3877 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3878 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3880 ** In other words, the initial ":" or "$" or "@" or "?"
3881 ** is included as part of the name.)^
3882 ** ^Parameters of the form "?" without a following integer have no name
3883 ** and are referred to as "nameless" or "anonymous parameters".
3885 ** ^The first host parameter has an index of 1, not 0.
3887 ** ^If the value N is out of range or if the N-th parameter is
3888 ** nameless, then NULL is returned. ^The returned string is
3889 ** always in UTF-8 encoding even if the named parameter was
3890 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3891 ** [sqlite3_prepare16_v2()].
3893 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3894 ** [sqlite3_bind_parameter_count()], and
3895 ** [sqlite3_bind_parameter_index()].
3897 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3900 ** CAPI3REF: Index Of A Parameter With A Given Name
3901 ** METHOD: sqlite3_stmt
3903 ** ^Return the index of an SQL parameter given its name. ^The
3904 ** index value returned is suitable for use as the second
3905 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3906 ** is returned if no matching parameter is found. ^The parameter
3907 ** name must be given in UTF-8 even if the original statement
3908 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3910 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3911 ** [sqlite3_bind_parameter_count()], and
3912 ** [sqlite3_bind_parameter_name()].
3914 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3917 ** CAPI3REF: Reset All Bindings On A Prepared Statement
3918 ** METHOD: sqlite3_stmt
3920 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3921 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3922 ** ^Use this routine to reset all host parameters to NULL.
3924 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3927 ** CAPI3REF: Number Of Columns In A Result Set
3928 ** METHOD: sqlite3_stmt
3930 ** ^Return the number of columns in the result set returned by the
3931 ** [prepared statement]. ^If this routine returns 0, that means the
3932 ** [prepared statement] returns no data (for example an [UPDATE]).
3933 ** ^However, just because this routine returns a positive number does not
3934 ** mean that one or more rows of data will be returned. ^A SELECT statement
3935 ** will always have a positive sqlite3_column_count() but depending on the
3936 ** WHERE clause constraints and the table content, it might return no rows.
3938 ** See also: [sqlite3_data_count()]
3940 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3943 ** CAPI3REF: Column Names In A Result Set
3944 ** METHOD: sqlite3_stmt
3946 ** ^These routines return the name assigned to a particular column
3947 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3948 ** interface returns a pointer to a zero-terminated UTF-8 string
3949 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3950 ** UTF-16 string. ^The first parameter is the [prepared statement]
3951 ** that implements the [SELECT] statement. ^The second parameter is the
3952 ** column number. ^The leftmost column is number 0.
3954 ** ^The returned string pointer is valid until either the [prepared statement]
3955 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3956 ** reprepared by the first call to [sqlite3_step()] for a particular run
3957 ** or until the next call to
3958 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3960 ** ^If sqlite3_malloc() fails during the processing of either routine
3961 ** (for example during a conversion from UTF-8 to UTF-16) then a
3962 ** NULL pointer is returned.
3964 ** ^The name of a result column is the value of the "AS" clause for
3965 ** that column, if there is an AS clause. If there is no AS clause
3966 ** then the name of the column is unspecified and may change from
3967 ** one release of SQLite to the next.
3969 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3970 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3973 ** CAPI3REF: Source Of Data In A Query Result
3974 ** METHOD: sqlite3_stmt
3976 ** ^These routines provide a means to determine the database, table, and
3977 ** table column that is the origin of a particular result column in
3978 ** [SELECT] statement.
3979 ** ^The name of the database or table or column can be returned as
3980 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3981 ** the database name, the _table_ routines return the table name, and
3982 ** the origin_ routines return the column name.
3983 ** ^The returned string is valid until the [prepared statement] is destroyed
3984 ** using [sqlite3_finalize()] or until the statement is automatically
3985 ** reprepared by the first call to [sqlite3_step()] for a particular run
3986 ** or until the same information is requested
3987 ** again in a different encoding.
3989 ** ^The names returned are the original un-aliased names of the
3990 ** database, table, and column.
3992 ** ^The first argument to these interfaces is a [prepared statement].
3993 ** ^These functions return information about the Nth result column returned by
3994 ** the statement, where N is the second function argument.
3995 ** ^The left-most column is column 0 for these routines.
3997 ** ^If the Nth column returned by the statement is an expression or
3998 ** subquery and is not a column value, then all of these functions return
3999 ** NULL. ^These routine might also return NULL if a memory allocation error
4000 ** occurs. ^Otherwise, they return the name of the attached database, table,
4001 ** or column that query result column was extracted from.
4003 ** ^As with all other SQLite APIs, those whose names end with "16" return
4004 ** UTF-16 encoded strings and the other functions return UTF-8.
4006 ** ^These APIs are only available if the library was compiled with the
4007 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4009 ** If two or more threads call one or more of these routines against the same
4010 ** prepared statement and column at the same time then the results are
4013 ** If two or more threads call one or more
4014 ** [sqlite3_column_database_name | column metadata interfaces]
4015 ** for the same [prepared statement] and result column
4016 ** at the same time then the results are undefined.
4018 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4019 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4020 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4021 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4022 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4023 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4026 ** CAPI3REF: Declared Datatype Of A Query Result
4027 ** METHOD: sqlite3_stmt
4029 ** ^(The first parameter is a [prepared statement].
4030 ** If this statement is a [SELECT] statement and the Nth column of the
4031 ** returned result set of that [SELECT] is a table column (not an
4032 ** expression or subquery) then the declared type of the table
4033 ** column is returned.)^ ^If the Nth column of the result set is an
4034 ** expression or subquery, then a NULL pointer is returned.
4035 ** ^The returned string is always UTF-8 encoded.
4037 ** ^(For example, given the database schema:
4039 ** CREATE TABLE t1(c1 VARIANT);
4041 ** and the following statement to be compiled:
4043 ** SELECT c1 + 1, c1 FROM t1;
4045 ** this routine would return the string "VARIANT" for the second result
4046 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4048 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4049 ** is declared to contain a particular type does not mean that the
4050 ** data stored in that column is of the declared type. SQLite is
4051 ** strongly typed, but the typing is dynamic not static. ^Type
4052 ** is associated with individual values, not with the containers
4053 ** used to hold those values.
4055 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4056 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4059 ** CAPI3REF: Evaluate An SQL Statement
4060 ** METHOD: sqlite3_stmt
4062 ** After a [prepared statement] has been prepared using either
4063 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
4064 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4065 ** must be called one or more times to evaluate the statement.
4067 ** The details of the behavior of the sqlite3_step() interface depend
4068 ** on whether the statement was prepared using the newer "v2" interface
4069 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
4070 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4071 ** new "v2" interface is recommended for new applications but the legacy
4072 ** interface will continue to be supported.
4074 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4075 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4076 ** ^With the "v2" interface, any of the other [result codes] or
4077 ** [extended result codes] might be returned as well.
4079 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4080 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4081 ** or occurs outside of an explicit transaction, then you can retry the
4082 ** statement. If the statement is not a [COMMIT] and occurs within an
4083 ** explicit transaction then you should rollback the transaction before
4086 ** ^[SQLITE_DONE] means that the statement has finished executing
4087 ** successfully. sqlite3_step() should not be called again on this virtual
4088 ** machine without first calling [sqlite3_reset()] to reset the virtual
4089 ** machine back to its initial state.
4091 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4092 ** is returned each time a new row of data is ready for processing by the
4093 ** caller. The values may be accessed using the [column access functions].
4094 ** sqlite3_step() is called again to retrieve the next row of data.
4096 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4097 ** violation) has occurred. sqlite3_step() should not be called again on
4098 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4099 ** ^With the legacy interface, a more specific error code (for example,
4100 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4101 ** can be obtained by calling [sqlite3_reset()] on the
4102 ** [prepared statement]. ^In the "v2" interface,
4103 ** the more specific error code is returned directly by sqlite3_step().
4105 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4106 ** Perhaps it was called on a [prepared statement] that has
4107 ** already been [sqlite3_finalize | finalized] or on one that had
4108 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4109 ** be the case that the same database connection is being used by two or
4110 ** more threads at the same moment in time.
4112 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4113 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4114 ** other than [SQLITE_ROW] before any subsequent invocation of
4115 ** sqlite3_step(). Failure to reset the prepared statement using
4116 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4117 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4118 ** sqlite3_step() began
4119 ** calling [sqlite3_reset()] automatically in this circumstance rather
4120 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4121 ** break because any application that ever receives an SQLITE_MISUSE error
4122 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4123 ** can be used to restore the legacy behavior.
4125 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4126 ** API always returns a generic error code, [SQLITE_ERROR], following any
4127 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4128 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4129 ** specific [error codes] that better describes the error.
4130 ** We admit that this is a goofy design. The problem has been fixed
4131 ** with the "v2" interface. If you prepare all of your SQL statements
4132 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
4133 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4134 ** then the more specific [error codes] are returned directly
4135 ** by sqlite3_step(). The use of the "v2" interface is recommended.
4137 SQLITE_API int sqlite3_step(sqlite3_stmt*);
4140 ** CAPI3REF: Number of columns in a result set
4141 ** METHOD: sqlite3_stmt
4143 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
4144 ** current row of the result set of [prepared statement] P.
4145 ** ^If prepared statement P does not have results ready to return
4146 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4147 ** interfaces) then sqlite3_data_count(P) returns 0.
4148 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4149 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4150 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4151 ** will return non-zero if previous call to [sqlite3_step](P) returned
4152 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4153 ** where it always returns zero since each step of that multi-step
4154 ** pragma returns 0 columns of data.
4156 ** See also: [sqlite3_column_count()]
4158 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4161 ** CAPI3REF: Fundamental Datatypes
4162 ** KEYWORDS: SQLITE_TEXT
4164 ** ^(Every value in SQLite has one of five fundamental datatypes:
4167 ** <li> 64-bit signed integer
4168 ** <li> 64-bit IEEE floating point number
4174 ** These constants are codes for each of those types.
4176 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4177 ** for a completely different meaning. Software that links against both
4178 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4181 #define SQLITE_INTEGER 1
4182 #define SQLITE_FLOAT 2
4183 #define SQLITE_BLOB 4
4184 #define SQLITE_NULL 5
4188 # define SQLITE_TEXT 3
4190 #define SQLITE3_TEXT 3
4193 ** CAPI3REF: Result Values From A Query
4194 ** KEYWORDS: {column access functions}
4195 ** METHOD: sqlite3_stmt
4197 ** ^These routines return information about a single column of the current
4198 ** result row of a query. ^In every case the first argument is a pointer
4199 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4200 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4201 ** and the second argument is the index of the column for which information
4202 ** should be returned. ^The leftmost column of the result set has the index 0.
4203 ** ^The number of columns in the result can be determined using
4204 ** [sqlite3_column_count()].
4206 ** If the SQL statement does not currently point to a valid row, or if the
4207 ** column index is out of range, the result is undefined.
4208 ** These routines may only be called when the most recent call to
4209 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4210 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4211 ** If any of these routines are called after [sqlite3_reset()] or
4212 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4213 ** something other than [SQLITE_ROW], the results are undefined.
4214 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4215 ** are called from a different thread while any of these routines
4216 ** are pending, then the results are undefined.
4218 ** ^The sqlite3_column_type() routine returns the
4219 ** [SQLITE_INTEGER | datatype code] for the initial data type
4220 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4221 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
4222 ** returned by sqlite3_column_type() is only meaningful if no type
4223 ** conversions have occurred as described below. After a type conversion,
4224 ** the value returned by sqlite3_column_type() is undefined. Future
4225 ** versions of SQLite may change the behavior of sqlite3_column_type()
4226 ** following a type conversion.
4228 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4229 ** routine returns the number of bytes in that BLOB or string.
4230 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4231 ** the string to UTF-8 and then returns the number of bytes.
4232 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
4233 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4234 ** the number of bytes in that string.
4235 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4237 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4238 ** routine returns the number of bytes in that BLOB or string.
4239 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4240 ** the string to UTF-16 and then returns the number of bytes.
4241 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4242 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4243 ** the number of bytes in that string.
4244 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4246 ** ^The values returned by [sqlite3_column_bytes()] and
4247 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4248 ** of the string. ^For clarity: the values returned by
4249 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4250 ** bytes in the string, not the number of characters.
4252 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4253 ** even empty strings, are always zero-terminated. ^The return
4254 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4256 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4257 ** [unprotected sqlite3_value] object. In a multithreaded environment,
4258 ** an unprotected sqlite3_value object may only be used safely with
4259 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
4260 ** If the [unprotected sqlite3_value] object returned by
4261 ** [sqlite3_column_value()] is used in any other way, including calls
4262 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4263 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4265 ** These routines attempt to convert the value where appropriate. ^For
4266 ** example, if the internal representation is FLOAT and a text result
4267 ** is requested, [sqlite3_snprintf()] is used internally to perform the
4268 ** conversion automatically. ^(The following table details the conversions
4269 ** that are applied:
4272 ** <table border="1">
4273 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4275 ** <tr><td> NULL <td> INTEGER <td> Result is 0
4276 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4277 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4278 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4279 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4280 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4281 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4282 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4283 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4284 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4285 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4286 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4287 ** <tr><td> TEXT <td> BLOB <td> No change
4288 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4289 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4290 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4294 ** Note that when type conversions occur, pointers returned by prior
4295 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4296 ** sqlite3_column_text16() may be invalidated.
4297 ** Type conversions and pointer invalidations might occur
4298 ** in the following cases:
4301 ** <li> The initial content is a BLOB and sqlite3_column_text() or
4302 ** sqlite3_column_text16() is called. A zero-terminator might
4303 ** need to be added to the string.</li>
4304 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4305 ** sqlite3_column_text16() is called. The content must be converted
4307 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4308 ** sqlite3_column_text() is called. The content must be converted
4312 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4313 ** not invalidate a prior pointer, though of course the content of the buffer
4314 ** that the prior pointer references will have been modified. Other kinds
4315 ** of conversion are done in place when it is possible, but sometimes they
4316 ** are not possible and in those cases prior pointers are invalidated.
4318 ** The safest policy is to invoke these routines
4319 ** in one of the following ways:
4322 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4323 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4324 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4327 ** In other words, you should call sqlite3_column_text(),
4328 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4329 ** into the desired format, then invoke sqlite3_column_bytes() or
4330 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4331 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4332 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4333 ** with calls to sqlite3_column_bytes().
4335 ** ^The pointers returned are valid until a type conversion occurs as
4336 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4337 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4338 ** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned
4339 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4340 ** [sqlite3_free()].
4342 ** ^(If a memory allocation error occurs during the evaluation of any
4343 ** of these routines, a default value is returned. The default value
4344 ** is either the integer 0, the floating point number 0.0, or a NULL
4345 ** pointer. Subsequent calls to [sqlite3_errcode()] will return
4346 ** [SQLITE_NOMEM].)^
4348 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4349 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4350 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4351 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4352 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4353 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4354 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4355 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4356 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4357 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4360 ** CAPI3REF: Destroy A Prepared Statement Object
4361 ** DESTRUCTOR: sqlite3_stmt
4363 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4364 ** ^If the most recent evaluation of the statement encountered no errors
4365 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
4366 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4367 ** sqlite3_finalize(S) returns the appropriate [error code] or
4368 ** [extended error code].
4370 ** ^The sqlite3_finalize(S) routine can be called at any point during
4371 ** the life cycle of [prepared statement] S:
4372 ** before statement S is ever evaluated, after
4373 ** one or more calls to [sqlite3_reset()], or after any call
4374 ** to [sqlite3_step()] regardless of whether or not the statement has
4375 ** completed execution.
4377 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4379 ** The application must finalize every [prepared statement] in order to avoid
4380 ** resource leaks. It is a grievous error for the application to try to use
4381 ** a prepared statement after it has been finalized. Any use of a prepared
4382 ** statement after it has been finalized can result in undefined and
4383 ** undesirable behavior such as segfaults and heap corruption.
4385 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4388 ** CAPI3REF: Reset A Prepared Statement Object
4389 ** METHOD: sqlite3_stmt
4391 ** The sqlite3_reset() function is called to reset a [prepared statement]
4392 ** object back to its initial state, ready to be re-executed.
4393 ** ^Any SQL statement variables that had values bound to them using
4394 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4395 ** Use [sqlite3_clear_bindings()] to reset the bindings.
4397 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4398 ** back to the beginning of its program.
4400 ** ^If the most recent call to [sqlite3_step(S)] for the
4401 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4402 ** or if [sqlite3_step(S)] has never before been called on S,
4403 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
4405 ** ^If the most recent call to [sqlite3_step(S)] for the
4406 ** [prepared statement] S indicated an error, then
4407 ** [sqlite3_reset(S)] returns an appropriate [error code].
4409 ** ^The [sqlite3_reset(S)] interface does not change the values
4410 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4412 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4415 ** CAPI3REF: Create Or Redefine SQL Functions
4416 ** KEYWORDS: {function creation routines}
4417 ** KEYWORDS: {application-defined SQL function}
4418 ** KEYWORDS: {application-defined SQL functions}
4421 ** ^These functions (collectively known as "function creation routines")
4422 ** are used to add SQL functions or aggregates or to redefine the behavior
4423 ** of existing SQL functions or aggregates. The only differences between
4424 ** these routines are the text encoding expected for
4425 ** the second parameter (the name of the function being created)
4426 ** and the presence or absence of a destructor callback for
4427 ** the application data pointer.
4429 ** ^The first parameter is the [database connection] to which the SQL
4430 ** function is to be added. ^If an application uses more than one database
4431 ** connection then application-defined SQL functions must be added
4432 ** to each database connection separately.
4434 ** ^The second parameter is the name of the SQL function to be created or
4435 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4436 ** representation, exclusive of the zero-terminator. ^Note that the name
4437 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4438 ** ^Any attempt to create a function with a longer name
4439 ** will result in [SQLITE_MISUSE] being returned.
4441 ** ^The third parameter (nArg)
4442 ** is the number of arguments that the SQL function or
4443 ** aggregate takes. ^If this parameter is -1, then the SQL function or
4444 ** aggregate may take any number of arguments between 0 and the limit
4445 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4446 ** parameter is less than -1 or greater than 127 then the behavior is
4449 ** ^The fourth parameter, eTextRep, specifies what
4450 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4451 ** its parameters. The application should set this parameter to
4452 ** [SQLITE_UTF16LE] if the function implementation invokes
4453 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4454 ** implementation invokes [sqlite3_value_text16be()] on an input, or
4455 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4456 ** otherwise. ^The same SQL function may be registered multiple times using
4457 ** different preferred text encodings, with different implementations for
4459 ** ^When multiple implementations of the same function are available, SQLite
4460 ** will pick the one that involves the least amount of data conversion.
4462 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4463 ** to signal that the function will always return the same result given
4464 ** the same inputs within a single SQL statement. Most SQL functions are
4465 ** deterministic. The built-in [random()] SQL function is an example of a
4466 ** function that is not deterministic. The SQLite query planner is able to
4467 ** perform additional optimizations on deterministic functions, so use
4468 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4470 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4471 ** function can gain access to this pointer using [sqlite3_user_data()].)^
4473 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4474 ** pointers to C-language functions that implement the SQL function or
4475 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4476 ** callback only; NULL pointers must be passed as the xStep and xFinal
4477 ** parameters. ^An aggregate SQL function requires an implementation of xStep
4478 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4479 ** SQL function or aggregate, pass NULL pointers for all three function
4482 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4483 ** then it is destructor for the application data pointer.
4484 ** The destructor is invoked when the function is deleted, either by being
4485 ** overloaded or when the database connection closes.)^
4486 ** ^The destructor is also invoked if the call to
4487 ** sqlite3_create_function_v2() fails.
4488 ** ^When the destructor callback of the tenth parameter is invoked, it
4489 ** is passed a single argument which is a copy of the application data
4490 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
4492 ** ^It is permitted to register multiple implementations of the same
4493 ** functions with the same name but with either differing numbers of
4494 ** arguments or differing preferred text encodings. ^SQLite will use
4495 ** the implementation that most closely matches the way in which the
4496 ** SQL function is used. ^A function implementation with a non-negative
4497 ** nArg parameter is a better match than a function implementation with
4498 ** a negative nArg. ^A function where the preferred text encoding
4499 ** matches the database encoding is a better
4500 ** match than a function where the encoding is different.
4501 ** ^A function where the encoding difference is between UTF16le and UTF16be
4502 ** is a closer match than a function where the encoding difference is
4503 ** between UTF8 and UTF16.
4505 ** ^Built-in functions may be overloaded by new application-defined functions.
4507 ** ^An application-defined function is permitted to call other
4508 ** SQLite interfaces. However, such calls must not
4509 ** close the database connection nor finalize or reset the prepared
4510 ** statement in which the function is running.
4512 SQLITE_API int sqlite3_create_function(
4514 const char *zFunctionName,
4518 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4519 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4520 void (*xFinal)(sqlite3_context*)
4522 SQLITE_API int sqlite3_create_function16(
4524 const void *zFunctionName,
4528 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4529 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4530 void (*xFinal)(sqlite3_context*)
4532 SQLITE_API int sqlite3_create_function_v2(
4534 const char *zFunctionName,
4538 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4539 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4540 void (*xFinal)(sqlite3_context*),
4541 void(*xDestroy)(void*)
4545 ** CAPI3REF: Text Encodings
4547 ** These constant define integer codes that represent the various
4548 ** text encodings supported by SQLite.
4550 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4551 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4552 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4553 #define SQLITE_UTF16 4 /* Use native byte order */
4554 #define SQLITE_ANY 5 /* Deprecated */
4555 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4558 ** CAPI3REF: Function Flags
4560 ** These constants may be ORed together with the
4561 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4562 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4563 ** [sqlite3_create_function_v2()].
4565 #define SQLITE_DETERMINISTIC 0x800
4568 ** CAPI3REF: Deprecated Functions
4571 ** These functions are [deprecated]. In order to maintain
4572 ** backwards compatibility with older code, these functions continue
4573 ** to be supported. However, new applications should avoid
4574 ** the use of these functions. To encourage programmers to avoid
4575 ** these functions, we will not explain what they do.
4577 #ifndef SQLITE_OMIT_DEPRECATED
4578 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4579 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4580 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4581 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4582 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4583 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4584 void*,sqlite3_int64);
4588 ** CAPI3REF: Obtaining SQL Values
4589 ** METHOD: sqlite3_value
4591 ** The C-language implementation of SQL functions and aggregates uses
4592 ** this set of interface routines to access the parameter values on
4593 ** the function or aggregate.
4595 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4596 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4597 ** define callbacks that implement the SQL functions and aggregates.
4598 ** The 3rd parameter to these callbacks is an array of pointers to
4599 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
4600 ** each parameter to the SQL function. These routines are used to
4601 ** extract values from the [sqlite3_value] objects.
4603 ** These routines work only with [protected sqlite3_value] objects.
4604 ** Any attempt to use these routines on an [unprotected sqlite3_value]
4605 ** object results in undefined behavior.
4607 ** ^These routines work just like the corresponding [column access functions]
4608 ** except that these routines take a single [protected sqlite3_value] object
4609 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4611 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4612 ** in the native byte-order of the host machine. ^The
4613 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4614 ** extract UTF-16 strings as big-endian and little-endian respectively.
4616 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
4617 ** numeric affinity to the value. This means that an attempt is
4618 ** made to convert the value to an integer or floating point. If
4619 ** such a conversion is possible without loss of information (in other
4620 ** words, if the value is a string that looks like a number)
4621 ** then the conversion is performed. Otherwise no conversion occurs.
4622 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4624 ** Please pay particular attention to the fact that the pointer returned
4625 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4626 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4627 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4628 ** or [sqlite3_value_text16()].
4630 ** These routines must be called from the same thread as
4631 ** the SQL function that supplied the [sqlite3_value*] parameters.
4633 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4634 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4635 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4636 SQLITE_API double sqlite3_value_double(sqlite3_value*);
4637 SQLITE_API int sqlite3_value_int(sqlite3_value*);
4638 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4639 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4640 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4641 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4642 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4643 SQLITE_API int sqlite3_value_type(sqlite3_value*);
4644 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4647 ** CAPI3REF: Finding The Subtype Of SQL Values
4648 ** METHOD: sqlite3_value
4650 ** The sqlite3_value_subtype(V) function returns the subtype for
4651 ** an [application-defined SQL function] argument V. The subtype
4652 ** information can be used to pass a limited amount of context from
4653 ** one SQL function to another. Use the [sqlite3_result_subtype()]
4654 ** routine to set the subtype for the return value of an SQL function.
4656 ** SQLite makes no use of subtype itself. It merely passes the subtype
4657 ** from the result of one [application-defined SQL function] into the
4658 ** input of another.
4660 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
4663 ** CAPI3REF: Copy And Free SQL Values
4664 ** METHOD: sqlite3_value
4666 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
4667 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
4668 ** is a [protected sqlite3_value] object even if the input is not.
4669 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
4670 ** memory allocation fails.
4672 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
4673 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
4674 ** then sqlite3_value_free(V) is a harmless no-op.
4676 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
4677 SQLITE_API void sqlite3_value_free(sqlite3_value*);
4680 ** CAPI3REF: Obtain Aggregate Function Context
4681 ** METHOD: sqlite3_context
4683 ** Implementations of aggregate SQL functions use this
4684 ** routine to allocate memory for storing their state.
4686 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4687 ** for a particular aggregate function, SQLite
4688 ** allocates N of memory, zeroes out that memory, and returns a pointer
4689 ** to the new memory. ^On second and subsequent calls to
4690 ** sqlite3_aggregate_context() for the same aggregate function instance,
4691 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
4692 ** called once for each invocation of the xStep callback and then one
4693 ** last time when the xFinal callback is invoked. ^(When no rows match
4694 ** an aggregate query, the xStep() callback of the aggregate function
4695 ** implementation is never called and xFinal() is called exactly once.
4696 ** In those cases, sqlite3_aggregate_context() might be called for the
4697 ** first time from within xFinal().)^
4699 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4700 ** when first called if N is less than or equal to zero or if a memory
4701 ** allocate error occurs.
4703 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4704 ** determined by the N parameter on first successful call. Changing the
4705 ** value of N in subsequent call to sqlite3_aggregate_context() within
4706 ** the same aggregate function instance will not resize the memory
4707 ** allocation.)^ Within the xFinal callback, it is customary to set
4708 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4709 ** pointless memory allocations occur.
4711 ** ^SQLite automatically frees the memory allocated by
4712 ** sqlite3_aggregate_context() when the aggregate query concludes.
4714 ** The first parameter must be a copy of the
4715 ** [sqlite3_context | SQL function context] that is the first parameter
4716 ** to the xStep or xFinal callback routine that implements the aggregate
4719 ** This routine must be called from the same thread in which
4720 ** the aggregate SQL function is running.
4722 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4725 ** CAPI3REF: User Data For Functions
4726 ** METHOD: sqlite3_context
4728 ** ^The sqlite3_user_data() interface returns a copy of
4729 ** the pointer that was the pUserData parameter (the 5th parameter)
4730 ** of the [sqlite3_create_function()]
4731 ** and [sqlite3_create_function16()] routines that originally
4732 ** registered the application defined function.
4734 ** This routine must be called from the same thread in which
4735 ** the application-defined function is running.
4737 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4740 ** CAPI3REF: Database Connection For Functions
4741 ** METHOD: sqlite3_context
4743 ** ^The sqlite3_context_db_handle() interface returns a copy of
4744 ** the pointer to the [database connection] (the 1st parameter)
4745 ** of the [sqlite3_create_function()]
4746 ** and [sqlite3_create_function16()] routines that originally
4747 ** registered the application defined function.
4749 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4752 ** CAPI3REF: Function Auxiliary Data
4753 ** METHOD: sqlite3_context
4755 ** These functions may be used by (non-aggregate) SQL functions to
4756 ** associate metadata with argument values. If the same value is passed to
4757 ** multiple invocations of the same SQL function during query execution, under
4758 ** some circumstances the associated metadata may be preserved. An example
4759 ** of where this might be useful is in a regular-expression matching
4760 ** function. The compiled version of the regular expression can be stored as
4761 ** metadata associated with the pattern string.
4762 ** Then as long as the pattern string remains the same,
4763 ** the compiled regular expression can be reused on multiple
4764 ** invocations of the same function.
4766 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
4767 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
4768 ** value to the application-defined function. ^N is zero for the left-most
4769 ** function argument. ^If there is no metadata
4770 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
4771 ** returns a NULL pointer.
4773 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4774 ** argument of the application-defined function. ^Subsequent
4775 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4776 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4777 ** NULL if the metadata has been discarded.
4778 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4779 ** SQLite will invoke the destructor function X with parameter P exactly
4780 ** once, when the metadata is discarded.
4781 ** SQLite is free to discard the metadata at any time, including: <ul>
4782 ** <li> ^(when the corresponding function parameter changes)^, or
4783 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4784 ** SQL statement)^, or
4785 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
4787 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
4788 ** allocation error occurs.)^ </ul>
4790 ** Note the last bullet in particular. The destructor X in
4791 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4792 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
4793 ** should be called near the end of the function implementation and the
4794 ** function implementation should not make any use of P after
4795 ** sqlite3_set_auxdata() has been called.
4797 ** ^(In practice, metadata is preserved between function calls for
4798 ** function parameters that are compile-time constants, including literal
4799 ** values and [parameters] and expressions composed from the same.)^
4801 ** The value of the N parameter to these interfaces should be non-negative.
4802 ** Future enhancements may make use of negative N values to define new
4803 ** kinds of function caching behavior.
4805 ** These routines must be called from the same thread in which
4806 ** the SQL function is running.
4808 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4809 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4813 ** CAPI3REF: Constants Defining Special Destructor Behavior
4815 ** These are special values for the destructor that is passed in as the
4816 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4817 ** argument is SQLITE_STATIC, it means that the content pointer is constant
4818 ** and will never change. It does not need to be destroyed. ^The
4819 ** SQLITE_TRANSIENT value means that the content will likely change in
4820 ** the near future and that SQLite should make its own private copy of
4821 ** the content before returning.
4823 ** The typedef is necessary to work around problems in certain
4826 typedef void (*sqlite3_destructor_type)(void*);
4827 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
4828 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4831 ** CAPI3REF: Setting The Result Of An SQL Function
4832 ** METHOD: sqlite3_context
4834 ** These routines are used by the xFunc or xFinal callbacks that
4835 ** implement SQL functions and aggregates. See
4836 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
4837 ** for additional information.
4839 ** These functions work very much like the [parameter binding] family of
4840 ** functions used to bind values to host parameters in prepared statements.
4841 ** Refer to the [SQL parameter] documentation for additional information.
4843 ** ^The sqlite3_result_blob() interface sets the result from
4844 ** an application-defined function to be the BLOB whose content is pointed
4845 ** to by the second parameter and which is N bytes long where N is the
4848 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
4849 ** interfaces set the result of the application-defined function to be
4850 ** a BLOB containing all zero bytes and N bytes in size.
4852 ** ^The sqlite3_result_double() interface sets the result from
4853 ** an application-defined function to be a floating point value specified
4854 ** by its 2nd argument.
4856 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4857 ** cause the implemented SQL function to throw an exception.
4858 ** ^SQLite uses the string pointed to by the
4859 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4860 ** as the text of an error message. ^SQLite interprets the error
4861 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4862 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4863 ** byte order. ^If the third parameter to sqlite3_result_error()
4864 ** or sqlite3_result_error16() is negative then SQLite takes as the error
4865 ** message all text up through the first zero character.
4866 ** ^If the third parameter to sqlite3_result_error() or
4867 ** sqlite3_result_error16() is non-negative then SQLite takes that many
4868 ** bytes (not characters) from the 2nd parameter as the error message.
4869 ** ^The sqlite3_result_error() and sqlite3_result_error16()
4870 ** routines make a private copy of the error message text before
4871 ** they return. Hence, the calling function can deallocate or
4872 ** modify the text after they return without harm.
4873 ** ^The sqlite3_result_error_code() function changes the error code
4874 ** returned by SQLite as a result of an error in a function. ^By default,
4875 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4876 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4878 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4879 ** error indicating that a string or BLOB is too long to represent.
4881 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4882 ** error indicating that a memory allocation failed.
4884 ** ^The sqlite3_result_int() interface sets the return value
4885 ** of the application-defined function to be the 32-bit signed integer
4886 ** value given in the 2nd argument.
4887 ** ^The sqlite3_result_int64() interface sets the return value
4888 ** of the application-defined function to be the 64-bit signed integer
4889 ** value given in the 2nd argument.
4891 ** ^The sqlite3_result_null() interface sets the return value
4892 ** of the application-defined function to be NULL.
4894 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4895 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4896 ** set the return value of the application-defined function to be
4897 ** a text string which is represented as UTF-8, UTF-16 native byte order,
4898 ** UTF-16 little endian, or UTF-16 big endian, respectively.
4899 ** ^The sqlite3_result_text64() interface sets the return value of an
4900 ** application-defined function to be a text string in an encoding
4901 ** specified by the fifth (and last) parameter, which must be one
4902 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
4903 ** ^SQLite takes the text result from the application from
4904 ** the 2nd parameter of the sqlite3_result_text* interfaces.
4905 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4906 ** is negative, then SQLite takes result text from the 2nd parameter
4907 ** through the first zero character.
4908 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4909 ** is non-negative, then as many bytes (not characters) of the text
4910 ** pointed to by the 2nd parameter are taken as the application-defined
4911 ** function result. If the 3rd parameter is non-negative, then it
4912 ** must be the byte offset into the string where the NUL terminator would
4913 ** appear if the string where NUL terminated. If any NUL characters occur
4914 ** in the string at a byte offset that is less than the value of the 3rd
4915 ** parameter, then the resulting string will contain embedded NULs and the
4916 ** result of expressions operating on strings with embedded NULs is undefined.
4917 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4918 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4919 ** function as the destructor on the text or BLOB result when it has
4920 ** finished using that result.
4921 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4922 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4923 ** assumes that the text or BLOB result is in constant space and does not
4924 ** copy the content of the parameter nor call a destructor on the content
4925 ** when it has finished using that result.
4926 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4927 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4928 ** then SQLite makes a copy of the result into space obtained from
4929 ** from [sqlite3_malloc()] before it returns.
4931 ** ^The sqlite3_result_value() interface sets the result of
4932 ** the application-defined function to be a copy of the
4933 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4934 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4935 ** so that the [sqlite3_value] specified in the parameter may change or
4936 ** be deallocated after sqlite3_result_value() returns without harm.
4937 ** ^A [protected sqlite3_value] object may always be used where an
4938 ** [unprotected sqlite3_value] object is required, so either
4939 ** kind of [sqlite3_value] object can be used with this interface.
4941 ** If these routines are called from within the different thread
4942 ** than the one containing the application-defined function that received
4943 ** the [sqlite3_context] pointer, the results are undefined.
4945 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4946 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
4947 sqlite3_uint64,void(*)(void*));
4948 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4949 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4950 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4951 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4952 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4953 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4954 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4955 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4956 SQLITE_API void sqlite3_result_null(sqlite3_context*);
4957 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4958 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
4959 void(*)(void*), unsigned char encoding);
4960 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4961 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4962 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4963 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4964 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4965 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
4969 ** CAPI3REF: Setting The Subtype Of An SQL Function
4970 ** METHOD: sqlite3_context
4972 ** The sqlite3_result_subtype(C,T) function causes the subtype of
4973 ** the result from the [application-defined SQL function] with
4974 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
4975 ** of the subtype T are preserved in current versions of SQLite;
4976 ** higher order bits are discarded.
4977 ** The number of subtype bytes preserved by SQLite might increase
4978 ** in future releases of SQLite.
4980 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
4983 ** CAPI3REF: Define New Collating Sequences
4986 ** ^These functions add, remove, or modify a [collation] associated
4987 ** with the [database connection] specified as the first argument.
4989 ** ^The name of the collation is a UTF-8 string
4990 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4991 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4992 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4993 ** considered to be the same name.
4995 ** ^(The third argument (eTextRep) must be one of the constants:
4997 ** <li> [SQLITE_UTF8],
4998 ** <li> [SQLITE_UTF16LE],
4999 ** <li> [SQLITE_UTF16BE],
5000 ** <li> [SQLITE_UTF16], or
5001 ** <li> [SQLITE_UTF16_ALIGNED].
5003 ** ^The eTextRep argument determines the encoding of strings passed
5004 ** to the collating function callback, xCallback.
5005 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5006 ** force strings to be UTF16 with native byte order.
5007 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5008 ** on an even byte address.
5010 ** ^The fourth argument, pArg, is an application data pointer that is passed
5011 ** through as the first argument to the collating function callback.
5013 ** ^The fifth argument, xCallback, is a pointer to the collating function.
5014 ** ^Multiple collating functions can be registered using the same name but
5015 ** with different eTextRep parameters and SQLite will use whichever
5016 ** function requires the least amount of data transformation.
5017 ** ^If the xCallback argument is NULL then the collating function is
5018 ** deleted. ^When all collating functions having the same name are deleted,
5019 ** that collation is no longer usable.
5021 ** ^The collating function callback is invoked with a copy of the pArg
5022 ** application data pointer and with two strings in the encoding specified
5023 ** by the eTextRep argument. The collating function must return an
5024 ** integer that is negative, zero, or positive
5025 ** if the first string is less than, equal to, or greater than the second,
5026 ** respectively. A collating function must always return the same answer
5027 ** given the same inputs. If two or more collating functions are registered
5028 ** to the same collation name (using different eTextRep values) then all
5029 ** must give an equivalent answer when invoked with equivalent strings.
5030 ** The collating function must obey the following properties for all
5031 ** strings A, B, and C:
5034 ** <li> If A==B then B==A.
5035 ** <li> If A==B and B==C then A==C.
5036 ** <li> If A<B THEN B>A.
5037 ** <li> If A<B and B<C then A<C.
5040 ** If a collating function fails any of the above constraints and that
5041 ** collating function is registered and used, then the behavior of SQLite
5044 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5045 ** with the addition that the xDestroy callback is invoked on pArg when
5046 ** the collating function is deleted.
5047 ** ^Collating functions are deleted when they are overridden by later
5048 ** calls to the collation creation functions or when the
5049 ** [database connection] is closed using [sqlite3_close()].
5051 ** ^The xDestroy callback is <u>not</u> called if the
5052 ** sqlite3_create_collation_v2() function fails. Applications that invoke
5053 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5054 ** check the return code and dispose of the application data pointer
5055 ** themselves rather than expecting SQLite to deal with it for them.
5056 ** This is different from every other SQLite interface. The inconsistency
5057 ** is unfortunate but cannot be changed without breaking backwards
5060 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5062 SQLITE_API int sqlite3_create_collation(
5067 int(*xCompare)(void*,int,const void*,int,const void*)
5069 SQLITE_API int sqlite3_create_collation_v2(
5074 int(*xCompare)(void*,int,const void*,int,const void*),
5075 void(*xDestroy)(void*)
5077 SQLITE_API int sqlite3_create_collation16(
5082 int(*xCompare)(void*,int,const void*,int,const void*)
5086 ** CAPI3REF: Collation Needed Callbacks
5089 ** ^To avoid having to register all collation sequences before a database
5090 ** can be used, a single callback function may be registered with the
5091 ** [database connection] to be invoked whenever an undefined collation
5092 ** sequence is required.
5094 ** ^If the function is registered using the sqlite3_collation_needed() API,
5095 ** then it is passed the names of undefined collation sequences as strings
5096 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5097 ** the names are passed as UTF-16 in machine native byte order.
5098 ** ^A call to either function replaces the existing collation-needed callback.
5100 ** ^(When the callback is invoked, the first argument passed is a copy
5101 ** of the second argument to sqlite3_collation_needed() or
5102 ** sqlite3_collation_needed16(). The second argument is the database
5103 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5104 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5105 ** sequence function required. The fourth parameter is the name of the
5106 ** required collation sequence.)^
5108 ** The callback function should register the desired collation using
5109 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5110 ** [sqlite3_create_collation_v2()].
5112 SQLITE_API int sqlite3_collation_needed(
5115 void(*)(void*,sqlite3*,int eTextRep,const char*)
5117 SQLITE_API int sqlite3_collation_needed16(
5120 void(*)(void*,sqlite3*,int eTextRep,const void*)
5123 #ifdef SQLITE_HAS_CODEC
5125 ** Specify the key for an encrypted database. This routine should be
5126 ** called right after sqlite3_open().
5128 ** The code to implement this API is not available in the public release
5131 SQLITE_API int sqlite3_key(
5132 sqlite3 *db, /* Database to be rekeyed */
5133 const void *pKey, int nKey /* The key */
5135 SQLITE_API int sqlite3_key_v2(
5136 sqlite3 *db, /* Database to be rekeyed */
5137 const char *zDbName, /* Name of the database */
5138 const void *pKey, int nKey /* The key */
5142 ** Change the key on an open database. If the current database is not
5143 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5144 ** database is decrypted.
5146 ** The code to implement this API is not available in the public release
5149 SQLITE_API int sqlite3_rekey(
5150 sqlite3 *db, /* Database to be rekeyed */
5151 const void *pKey, int nKey /* The new key */
5153 SQLITE_API int sqlite3_rekey_v2(
5154 sqlite3 *db, /* Database to be rekeyed */
5155 const char *zDbName, /* Name of the database */
5156 const void *pKey, int nKey /* The new key */
5160 ** Specify the activation key for a SEE database. Unless
5161 ** activated, none of the SEE routines will work.
5163 SQLITE_API void sqlite3_activate_see(
5164 const char *zPassPhrase /* Activation phrase */
5168 #ifdef SQLITE_ENABLE_CEROD
5170 ** Specify the activation key for a CEROD database. Unless
5171 ** activated, none of the CEROD routines will work.
5173 SQLITE_API void sqlite3_activate_cerod(
5174 const char *zPassPhrase /* Activation phrase */
5179 ** CAPI3REF: Suspend Execution For A Short Time
5181 ** The sqlite3_sleep() function causes the current thread to suspend execution
5182 ** for at least a number of milliseconds specified in its parameter.
5184 ** If the operating system does not support sleep requests with
5185 ** millisecond time resolution, then the time will be rounded up to
5186 ** the nearest second. The number of milliseconds of sleep actually
5187 ** requested from the operating system is returned.
5189 ** ^SQLite implements this interface by calling the xSleep()
5190 ** method of the default [sqlite3_vfs] object. If the xSleep() method
5191 ** of the default VFS is not implemented correctly, or not implemented at
5192 ** all, then the behavior of sqlite3_sleep() may deviate from the description
5193 ** in the previous paragraphs.
5195 SQLITE_API int sqlite3_sleep(int);
5198 ** CAPI3REF: Name Of The Folder Holding Temporary Files
5200 ** ^(If this global variable is made to point to a string which is
5201 ** the name of a folder (a.k.a. directory), then all temporary files
5202 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5203 ** will be placed in that directory.)^ ^If this variable
5204 ** is a NULL pointer, then SQLite performs a search for an appropriate
5205 ** temporary file directory.
5207 ** Applications are strongly discouraged from using this global variable.
5208 ** It is required to set a temporary folder on Windows Runtime (WinRT).
5209 ** But for all other platforms, it is highly recommended that applications
5210 ** neither read nor write this variable. This global variable is a relic
5211 ** that exists for backwards compatibility of legacy applications and should
5212 ** be avoided in new projects.
5214 ** It is not safe to read or modify this variable in more than one
5215 ** thread at a time. It is not safe to read or modify this variable
5216 ** if a [database connection] is being used at the same time in a separate
5218 ** It is intended that this variable be set once
5219 ** as part of process initialization and before any SQLite interface
5220 ** routines have been called and that this variable remain unchanged
5223 ** ^The [temp_store_directory pragma] may modify this variable and cause
5224 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5225 ** the [temp_store_directory pragma] always assumes that any string
5226 ** that this variable points to is held in memory obtained from
5227 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5228 ** using [sqlite3_free].
5229 ** Hence, if this variable is modified directly, either it should be
5230 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5231 ** or else the use of the [temp_store_directory pragma] should be avoided.
5232 ** Except when requested by the [temp_store_directory pragma], SQLite
5233 ** does not free the memory that sqlite3_temp_directory points to. If
5234 ** the application wants that memory to be freed, it must do
5235 ** so itself, taking care to only do so after all [database connection]
5236 ** objects have been destroyed.
5238 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5239 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5240 ** features that require the use of temporary files may fail. Here is an
5241 ** example of how to do this using C++ with the Windows Runtime:
5243 ** <blockquote><pre>
5244 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5245 ** TemporaryFolder->Path->Data();
5246 ** char zPathBuf[MAX_PATH + 1];
5247 ** memset(zPathBuf, 0, sizeof(zPathBuf));
5248 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5249 ** NULL, NULL);
5250 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5251 ** </pre></blockquote>
5253 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5256 ** CAPI3REF: Name Of The Folder Holding Database Files
5258 ** ^(If this global variable is made to point to a string which is
5259 ** the name of a folder (a.k.a. directory), then all database files
5260 ** specified with a relative pathname and created or accessed by
5261 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5262 ** to be relative to that directory.)^ ^If this variable is a NULL
5263 ** pointer, then SQLite assumes that all database files specified
5264 ** with a relative pathname are relative to the current directory
5265 ** for the process. Only the windows VFS makes use of this global
5266 ** variable; it is ignored by the unix VFS.
5268 ** Changing the value of this variable while a database connection is
5269 ** open can result in a corrupt database.
5271 ** It is not safe to read or modify this variable in more than one
5272 ** thread at a time. It is not safe to read or modify this variable
5273 ** if a [database connection] is being used at the same time in a separate
5275 ** It is intended that this variable be set once
5276 ** as part of process initialization and before any SQLite interface
5277 ** routines have been called and that this variable remain unchanged
5280 ** ^The [data_store_directory pragma] may modify this variable and cause
5281 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5282 ** the [data_store_directory pragma] always assumes that any string
5283 ** that this variable points to is held in memory obtained from
5284 ** [sqlite3_malloc] and the pragma may attempt to free that memory
5285 ** using [sqlite3_free].
5286 ** Hence, if this variable is modified directly, either it should be
5287 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
5288 ** or else the use of the [data_store_directory pragma] should be avoided.
5290 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5293 ** CAPI3REF: Test For Auto-Commit Mode
5294 ** KEYWORDS: {autocommit mode}
5297 ** ^The sqlite3_get_autocommit() interface returns non-zero or
5298 ** zero if the given database connection is or is not in autocommit mode,
5299 ** respectively. ^Autocommit mode is on by default.
5300 ** ^Autocommit mode is disabled by a [BEGIN] statement.
5301 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5303 ** If certain kinds of errors occur on a statement within a multi-statement
5304 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5305 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5306 ** transaction might be rolled back automatically. The only way to
5307 ** find out whether SQLite automatically rolled back the transaction after
5308 ** an error is to use this function.
5310 ** If another thread changes the autocommit status of the database
5311 ** connection while this routine is running, then the return value
5314 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5317 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
5318 ** METHOD: sqlite3_stmt
5320 ** ^The sqlite3_db_handle interface returns the [database connection] handle
5321 ** to which a [prepared statement] belongs. ^The [database connection]
5322 ** returned by sqlite3_db_handle is the same [database connection]
5323 ** that was the first argument
5324 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5325 ** create the statement in the first place.
5327 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5330 ** CAPI3REF: Return The Filename For A Database Connection
5333 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5334 ** associated with database N of connection D. ^The main database file
5335 ** has the name "main". If there is no attached database N on the database
5336 ** connection D, or if database N is a temporary or in-memory database, then
5337 ** a NULL pointer is returned.
5339 ** ^The filename returned by this function is the output of the
5340 ** xFullPathname method of the [VFS]. ^In other words, the filename
5341 ** will be an absolute pathname, even if the filename used
5342 ** to open the database originally was a URI or relative pathname.
5344 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5347 ** CAPI3REF: Determine if a database is read-only
5350 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5351 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5352 ** the name of a database on connection D.
5354 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5357 ** CAPI3REF: Find the next prepared statement
5360 ** ^This interface returns a pointer to the next [prepared statement] after
5361 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5362 ** then this interface returns a pointer to the first prepared statement
5363 ** associated with the database connection pDb. ^If no prepared statement
5364 ** satisfies the conditions of this routine, it returns NULL.
5366 ** The [database connection] pointer D in a call to
5367 ** [sqlite3_next_stmt(D,S)] must refer to an open database
5368 ** connection and in particular must not be a NULL pointer.
5370 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5373 ** CAPI3REF: Commit And Rollback Notification Callbacks
5376 ** ^The sqlite3_commit_hook() interface registers a callback
5377 ** function to be invoked whenever a transaction is [COMMIT | committed].
5378 ** ^Any callback set by a previous call to sqlite3_commit_hook()
5379 ** for the same database connection is overridden.
5380 ** ^The sqlite3_rollback_hook() interface registers a callback
5381 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5382 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
5383 ** for the same database connection is overridden.
5384 ** ^The pArg argument is passed through to the callback.
5385 ** ^If the callback on a commit hook function returns non-zero,
5386 ** then the commit is converted into a rollback.
5388 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5389 ** return the P argument from the previous call of the same function
5390 ** on the same [database connection] D, or NULL for
5391 ** the first call for each function on D.
5393 ** The commit and rollback hook callbacks are not reentrant.
5394 ** The callback implementation must not do anything that will modify
5395 ** the database connection that invoked the callback. Any actions
5396 ** to modify the database connection must be deferred until after the
5397 ** completion of the [sqlite3_step()] call that triggered the commit
5398 ** or rollback hook in the first place.
5399 ** Note that running any other SQL statements, including SELECT statements,
5400 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5401 ** the database connections for the meaning of "modify" in this paragraph.
5403 ** ^Registering a NULL function disables the callback.
5405 ** ^When the commit hook callback routine returns zero, the [COMMIT]
5406 ** operation is allowed to continue normally. ^If the commit hook
5407 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5408 ** ^The rollback hook is invoked on a rollback that results from a commit
5409 ** hook returning non-zero, just as it would be with any other rollback.
5411 ** ^For the purposes of this API, a transaction is said to have been
5412 ** rolled back if an explicit "ROLLBACK" statement is executed, or
5413 ** an error or constraint causes an implicit rollback to occur.
5414 ** ^The rollback callback is not invoked if a transaction is
5415 ** automatically rolled back because the database connection is closed.
5417 ** See also the [sqlite3_update_hook()] interface.
5419 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5420 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5423 ** CAPI3REF: Data Change Notification Callbacks
5426 ** ^The sqlite3_update_hook() interface registers a callback function
5427 ** with the [database connection] identified by the first argument
5428 ** to be invoked whenever a row is updated, inserted or deleted in
5430 ** ^Any callback set by a previous call to this function
5431 ** for the same database connection is overridden.
5433 ** ^The second argument is a pointer to the function to invoke when a
5434 ** row is updated, inserted or deleted in a rowid table.
5435 ** ^The first argument to the callback is a copy of the third argument
5436 ** to sqlite3_update_hook().
5437 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5438 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
5440 ** ^The third and fourth arguments to the callback contain pointers to the
5441 ** database and table name containing the affected row.
5442 ** ^The final callback parameter is the [rowid] of the row.
5443 ** ^In the case of an update, this is the [rowid] after the update takes place.
5445 ** ^(The update hook is not invoked when internal system tables are
5446 ** modified (i.e. sqlite_master and sqlite_sequence).)^
5447 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5449 ** ^In the current implementation, the update hook
5450 ** is not invoked when conflicting rows are deleted because of an
5451 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5452 ** invoked when rows are deleted using the [truncate optimization].
5453 ** The exceptions defined in this paragraph might change in a future
5454 ** release of SQLite.
5456 ** The update hook implementation must not do anything that will modify
5457 ** the database connection that invoked the update hook. Any actions
5458 ** to modify the database connection must be deferred until after the
5459 ** completion of the [sqlite3_step()] call that triggered the update hook.
5460 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5461 ** database connections for the meaning of "modify" in this paragraph.
5463 ** ^The sqlite3_update_hook(D,C,P) function
5464 ** returns the P argument from the previous call
5465 ** on the same [database connection] D, or NULL for
5466 ** the first call on D.
5468 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5469 ** and [sqlite3_preupdate_hook()] interfaces.
5471 SQLITE_API void *sqlite3_update_hook(
5473 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5478 ** CAPI3REF: Enable Or Disable Shared Pager Cache
5480 ** ^(This routine enables or disables the sharing of the database cache
5481 ** and schema data structures between [database connection | connections]
5482 ** to the same database. Sharing is enabled if the argument is true
5483 ** and disabled if the argument is false.)^
5485 ** ^Cache sharing is enabled and disabled for an entire process.
5486 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5487 ** In prior versions of SQLite,
5488 ** sharing was enabled or disabled for each thread separately.
5490 ** ^(The cache sharing mode set by this interface effects all subsequent
5491 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5492 ** Existing database connections continue use the sharing mode
5493 ** that was in effect at the time they were opened.)^
5495 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5496 ** successfully. An [error code] is returned otherwise.)^
5498 ** ^Shared cache is disabled by default. But this might change in
5499 ** future releases of SQLite. Applications that care about shared
5500 ** cache setting should set it explicitly.
5502 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5503 ** and will always return SQLITE_MISUSE. On those systems,
5504 ** shared cache mode should be enabled per-database connection via
5505 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5507 ** This interface is threadsafe on processors where writing a
5508 ** 32-bit integer is atomic.
5510 ** See Also: [SQLite Shared-Cache Mode]
5512 SQLITE_API int sqlite3_enable_shared_cache(int);
5515 ** CAPI3REF: Attempt To Free Heap Memory
5517 ** ^The sqlite3_release_memory() interface attempts to free N bytes
5518 ** of heap memory by deallocating non-essential memory allocations
5519 ** held by the database library. Memory used to cache database
5520 ** pages to improve performance is an example of non-essential memory.
5521 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
5522 ** which might be more or less than the amount requested.
5523 ** ^The sqlite3_release_memory() routine is a no-op returning zero
5524 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5526 ** See also: [sqlite3_db_release_memory()]
5528 SQLITE_API int sqlite3_release_memory(int);
5531 ** CAPI3REF: Free Memory Used By A Database Connection
5534 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5535 ** memory as possible from database connection D. Unlike the
5536 ** [sqlite3_release_memory()] interface, this interface is in effect even
5537 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5540 ** See also: [sqlite3_release_memory()]
5542 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5545 ** CAPI3REF: Impose A Limit On Heap Size
5547 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5548 ** soft limit on the amount of heap memory that may be allocated by SQLite.
5549 ** ^SQLite strives to keep heap memory utilization below the soft heap
5550 ** limit by reducing the number of pages held in the page cache
5551 ** as heap memory usages approaches the limit.
5552 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
5553 ** below the limit, it will exceed the limit rather than generate
5554 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5555 ** is advisory only.
5557 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
5558 ** the soft heap limit prior to the call, or negative in the case of an
5559 ** error. ^If the argument N is negative
5560 ** then no change is made to the soft heap limit. Hence, the current
5561 ** size of the soft heap limit can be determined by invoking
5562 ** sqlite3_soft_heap_limit64() with a negative argument.
5564 ** ^If the argument N is zero then the soft heap limit is disabled.
5566 ** ^(The soft heap limit is not enforced in the current implementation
5567 ** if one or more of following conditions are true:
5570 ** <li> The soft heap limit is set to zero.
5571 ** <li> Memory accounting is disabled using a combination of the
5572 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5573 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5574 ** <li> An alternative page cache implementation is specified using
5575 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5576 ** <li> The page cache allocates from its own memory pool supplied
5577 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5581 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
5582 ** the soft heap limit is enforced
5583 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5584 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5585 ** the soft heap limit is enforced on every memory allocation. Without
5586 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5587 ** when memory is allocated by the page cache. Testing suggests that because
5588 ** the page cache is the predominate memory user in SQLite, most
5589 ** applications will achieve adequate soft heap limit enforcement without
5590 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5592 ** The circumstances under which SQLite will enforce the soft heap limit may
5593 ** changes in future releases of SQLite.
5595 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5598 ** CAPI3REF: Deprecated Soft Heap Limit Interface
5601 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5602 ** interface. This routine is provided for historical compatibility
5603 ** only. All new applications should use the
5604 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
5606 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5610 ** CAPI3REF: Extract Metadata About A Column Of A Table
5613 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
5614 ** information about column C of table T in database D
5615 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
5616 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
5617 ** the final five arguments with appropriate values if the specified
5618 ** column exists. ^The sqlite3_table_column_metadata() interface returns
5619 ** SQLITE_ERROR and if the specified column does not exist.
5620 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
5621 ** NULL pointer, then this routine simply checks for the existence of the
5622 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
5625 ** ^The column is identified by the second, third and fourth parameters to
5626 ** this function. ^(The second parameter is either the name of the database
5627 ** (i.e. "main", "temp", or an attached database) containing the specified
5628 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
5629 ** for the table using the same algorithm used by the database engine to
5630 ** resolve unqualified table references.
5632 ** ^The third and fourth parameters to this function are the table and column
5633 ** name of the desired column, respectively.
5635 ** ^Metadata is returned by writing to the memory locations passed as the 5th
5636 ** and subsequent parameters to this function. ^Any of these arguments may be
5637 ** NULL, in which case the corresponding element of metadata is omitted.
5640 ** <table border="1">
5641 ** <tr><th> Parameter <th> Output<br>Type <th> Description
5643 ** <tr><td> 5th <td> const char* <td> Data type
5644 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5645 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5646 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5647 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
5651 ** ^The memory pointed to by the character pointers returned for the
5652 ** declaration type and collation sequence is valid until the next
5653 ** call to any SQLite API function.
5655 ** ^If the specified table is actually a view, an [error code] is returned.
5657 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
5658 ** is not a [WITHOUT ROWID] table and an
5659 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5660 ** parameters are set for the explicitly declared column. ^(If there is no
5661 ** [INTEGER PRIMARY KEY] column, then the outputs
5662 ** for the [rowid] are set as follows:
5665 ** data type: "INTEGER"
5666 ** collation sequence: "BINARY"
5669 ** auto increment: 0
5672 ** ^This function causes all database schemas to be read from disk and
5673 ** parsed, if that has not already been done, and returns an error if
5674 ** any errors are encountered while loading the schema.
5676 SQLITE_API int sqlite3_table_column_metadata(
5677 sqlite3 *db, /* Connection handle */
5678 const char *zDbName, /* Database name or NULL */
5679 const char *zTableName, /* Table name */
5680 const char *zColumnName, /* Column name */
5681 char const **pzDataType, /* OUTPUT: Declared data type */
5682 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5683 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5684 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5685 int *pAutoinc /* OUTPUT: True if column is auto-increment */
5689 ** CAPI3REF: Load An Extension
5692 ** ^This interface loads an SQLite extension library from the named file.
5694 ** ^The sqlite3_load_extension() interface attempts to load an
5695 ** [SQLite extension] library contained in the file zFile. If
5696 ** the file cannot be loaded directly, attempts are made to load
5697 ** with various operating-system specific extensions added.
5698 ** So for example, if "samplelib" cannot be loaded, then names like
5699 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5702 ** ^The entry point is zProc.
5703 ** ^(zProc may be 0, in which case SQLite will try to come up with an
5704 ** entry point name on its own. It first tries "sqlite3_extension_init".
5705 ** If that does not work, it constructs a name "sqlite3_X_init" where the
5706 ** X is consists of the lower-case equivalent of all ASCII alphabetic
5707 ** characters in the filename from the last "/" to the first following
5708 ** "." and omitting any initial "lib".)^
5709 ** ^The sqlite3_load_extension() interface returns
5710 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5711 ** ^If an error occurs and pzErrMsg is not 0, then the
5712 ** [sqlite3_load_extension()] interface shall attempt to
5713 ** fill *pzErrMsg with error message text stored in memory
5714 ** obtained from [sqlite3_malloc()]. The calling function
5715 ** should free this memory by calling [sqlite3_free()].
5717 ** ^Extension loading must be enabled using
5718 ** [sqlite3_enable_load_extension()] or
5719 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
5720 ** prior to calling this API,
5721 ** otherwise an error will be returned.
5723 ** <b>Security warning:</b> It is recommended that the
5724 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
5725 ** interface. The use of the [sqlite3_enable_load_extension()] interface
5726 ** should be avoided. This will keep the SQL function [load_extension()]
5727 ** disabled and prevent SQL injections from giving attackers
5728 ** access to extension loading capabilities.
5730 ** See also the [load_extension() SQL function].
5732 SQLITE_API int sqlite3_load_extension(
5733 sqlite3 *db, /* Load the extension into this database connection */
5734 const char *zFile, /* Name of the shared library containing extension */
5735 const char *zProc, /* Entry point. Derived from zFile if 0 */
5736 char **pzErrMsg /* Put error message here if not 0 */
5740 ** CAPI3REF: Enable Or Disable Extension Loading
5743 ** ^So as not to open security holes in older applications that are
5744 ** unprepared to deal with [extension loading], and as a means of disabling
5745 ** [extension loading] while evaluating user-entered SQL, the following API
5746 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5748 ** ^Extension loading is off by default.
5749 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5750 ** to turn extension loading on and call it with onoff==0 to turn
5751 ** it back off again.
5753 ** ^This interface enables or disables both the C-API
5754 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
5755 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
5756 ** to enable or disable only the C-API.)^
5758 ** <b>Security warning:</b> It is recommended that extension loading
5759 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
5760 ** rather than this interface, so the [load_extension()] SQL function
5761 ** remains disabled. This will prevent SQL injections from giving attackers
5762 ** access to extension loading capabilities.
5764 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5767 ** CAPI3REF: Automatically Load Statically Linked Extensions
5769 ** ^This interface causes the xEntryPoint() function to be invoked for
5770 ** each new [database connection] that is created. The idea here is that
5771 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5772 ** that is to be automatically loaded into all new database connections.
5774 ** ^(Even though the function prototype shows that xEntryPoint() takes
5775 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
5776 ** arguments and expects an integer result as if the signature of the
5777 ** entry point where as follows:
5779 ** <blockquote><pre>
5780 ** int xEntryPoint(
5781 ** sqlite3 *db,
5782 ** const char **pzErrMsg,
5783 ** const struct sqlite3_api_routines *pThunk
5785 ** </pre></blockquote>)^
5787 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5788 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5789 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5790 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5791 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5792 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5793 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5795 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5796 ** on the list of automatic extensions is a harmless no-op. ^No entry point
5797 ** will be called more than once for each database connection that is opened.
5799 ** See also: [sqlite3_reset_auto_extension()]
5800 ** and [sqlite3_cancel_auto_extension()]
5802 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
5805 ** CAPI3REF: Cancel Automatic Extension Loading
5807 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5808 ** initialization routine X that was registered using a prior call to
5809 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
5810 ** routine returns 1 if initialization routine X was successfully
5811 ** unregistered and it returns 0 if X was not on the list of initialization
5814 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
5817 ** CAPI3REF: Reset Automatic Extension Loading
5819 ** ^This interface disables all automatic extensions previously
5820 ** registered using [sqlite3_auto_extension()].
5822 SQLITE_API void sqlite3_reset_auto_extension(void);
5825 ** The interface to the virtual-table mechanism is currently considered
5826 ** to be experimental. The interface might change in incompatible ways.
5827 ** If this is a problem for you, do not use the interface at this time.
5829 ** When the virtual-table mechanism stabilizes, we will declare the
5830 ** interface fixed, support it indefinitely, and remove this comment.
5834 ** Structures used by the virtual table interface
5836 typedef struct sqlite3_vtab sqlite3_vtab;
5837 typedef struct sqlite3_index_info sqlite3_index_info;
5838 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5839 typedef struct sqlite3_module sqlite3_module;
5842 ** CAPI3REF: Virtual Table Object
5843 ** KEYWORDS: sqlite3_module {virtual table module}
5845 ** This structure, sometimes called a "virtual table module",
5846 ** defines the implementation of a [virtual tables].
5847 ** This structure consists mostly of methods for the module.
5849 ** ^A virtual table module is created by filling in a persistent
5850 ** instance of this structure and passing a pointer to that instance
5851 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5852 ** ^The registration remains valid until it is replaced by a different
5853 ** module or until the [database connection] closes. The content
5854 ** of this structure must not change while it is registered with
5855 ** any database connection.
5857 struct sqlite3_module {
5859 int (*xCreate)(sqlite3*, void *pAux,
5860 int argc, const char *const*argv,
5861 sqlite3_vtab **ppVTab, char**);
5862 int (*xConnect)(sqlite3*, void *pAux,
5863 int argc, const char *const*argv,
5864 sqlite3_vtab **ppVTab, char**);
5865 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5866 int (*xDisconnect)(sqlite3_vtab *pVTab);
5867 int (*xDestroy)(sqlite3_vtab *pVTab);
5868 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5869 int (*xClose)(sqlite3_vtab_cursor*);
5870 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5871 int argc, sqlite3_value **argv);
5872 int (*xNext)(sqlite3_vtab_cursor*);
5873 int (*xEof)(sqlite3_vtab_cursor*);
5874 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5875 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5876 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5877 int (*xBegin)(sqlite3_vtab *pVTab);
5878 int (*xSync)(sqlite3_vtab *pVTab);
5879 int (*xCommit)(sqlite3_vtab *pVTab);
5880 int (*xRollback)(sqlite3_vtab *pVTab);
5881 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5882 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5884 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5885 /* The methods above are in version 1 of the sqlite_module object. Those
5886 ** below are for version 2 and greater. */
5887 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5888 int (*xRelease)(sqlite3_vtab *pVTab, int);
5889 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5893 ** CAPI3REF: Virtual Table Indexing Information
5894 ** KEYWORDS: sqlite3_index_info
5896 ** The sqlite3_index_info structure and its substructures is used as part
5897 ** of the [virtual table] interface to
5898 ** pass information into and receive the reply from the [xBestIndex]
5899 ** method of a [virtual table module]. The fields under **Inputs** are the
5900 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
5901 ** results into the **Outputs** fields.
5903 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
5905 ** <blockquote>column OP expr</blockquote>
5907 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
5908 ** stored in aConstraint[].op using one of the
5909 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5910 ** ^(The index of the column is stored in
5911 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
5912 ** expr on the right-hand side can be evaluated (and thus the constraint
5913 ** is usable) and false if it cannot.)^
5915 ** ^The optimizer automatically inverts terms of the form "expr OP column"
5916 ** and makes other simplifications to the WHERE clause in an attempt to
5917 ** get as many WHERE clause terms into the form shown above as possible.
5918 ** ^The aConstraint[] array only reports WHERE clause terms that are
5919 ** relevant to the particular virtual table being queried.
5921 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
5922 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
5924 ** The colUsed field indicates which columns of the virtual table may be
5925 ** required by the current scan. Virtual table columns are numbered from
5926 ** zero in the order in which they appear within the CREATE TABLE statement
5927 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
5928 ** the corresponding bit is set within the colUsed mask if the column may be
5929 ** required by SQLite. If the table has at least 64 columns and any column
5930 ** to the right of the first 63 is required, then bit 63 of colUsed is also
5931 ** set. In other words, column iCol may be required if the expression
5932 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
5935 ** The [xBestIndex] method must fill aConstraintUsage[] with information
5936 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
5937 ** the right-hand side of the corresponding aConstraint[] is evaluated
5938 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
5939 ** is true, then the constraint is assumed to be fully handled by the
5940 ** virtual table and is not checked again by SQLite.)^
5942 ** ^The idxNum and idxPtr values are recorded and passed into the
5943 ** [xFilter] method.
5944 ** ^[sqlite3_free()] is used to free idxPtr if and only if
5945 ** needToFreeIdxPtr is true.
5947 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5948 ** the correct order to satisfy the ORDER BY clause so that no separate
5949 ** sorting step is required.
5951 ** ^The estimatedCost value is an estimate of the cost of a particular
5952 ** strategy. A cost of N indicates that the cost of the strategy is similar
5953 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
5954 ** indicates that the expense of the operation is similar to that of a
5955 ** binary search on a unique indexed field of an SQLite table with N rows.
5957 ** ^The estimatedRows value is an estimate of the number of rows that
5958 ** will be returned by the strategy.
5960 ** The xBestIndex method may optionally populate the idxFlags field with a
5961 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
5962 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
5963 ** assumes that the strategy may visit at most one row.
5965 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
5966 ** SQLite also assumes that if a call to the xUpdate() method is made as
5967 ** part of the same statement to delete or update a virtual table row and the
5968 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
5969 ** any database changes. In other words, if the xUpdate() returns
5970 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
5971 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
5972 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
5973 ** the xUpdate method are automatically rolled back by SQLite.
5975 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5976 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
5977 ** If a virtual table extension is
5978 ** used with an SQLite version earlier than 3.8.2, the results of attempting
5979 ** to read or write the estimatedRows field are undefined (but are likely
5980 ** to included crashing the application). The estimatedRows field should
5981 ** therefore only be used if [sqlite3_libversion_number()] returns a
5982 ** value greater than or equal to 3008002. Similarly, the idxFlags field
5983 ** was added for [version 3.9.0] ([dateof:3.9.0]).
5984 ** It may therefore only be used if
5985 ** sqlite3_libversion_number() returns a value greater than or equal to
5988 struct sqlite3_index_info {
5990 int nConstraint; /* Number of entries in aConstraint */
5991 struct sqlite3_index_constraint {
5992 int iColumn; /* Column constrained. -1 for ROWID */
5993 unsigned char op; /* Constraint operator */
5994 unsigned char usable; /* True if this constraint is usable */
5995 int iTermOffset; /* Used internally - xBestIndex should ignore */
5996 } *aConstraint; /* Table of WHERE clause constraints */
5997 int nOrderBy; /* Number of terms in the ORDER BY clause */
5998 struct sqlite3_index_orderby {
5999 int iColumn; /* Column number */
6000 unsigned char desc; /* True for DESC. False for ASC. */
6001 } *aOrderBy; /* The ORDER BY clause */
6003 struct sqlite3_index_constraint_usage {
6004 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6005 unsigned char omit; /* Do not code a test for this constraint */
6006 } *aConstraintUsage;
6007 int idxNum; /* Number used to identify the index */
6008 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6009 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6010 int orderByConsumed; /* True if output is already ordered */
6011 double estimatedCost; /* Estimated cost of using this index */
6012 /* Fields below are only available in SQLite 3.8.2 and later */
6013 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6014 /* Fields below are only available in SQLite 3.9.0 and later */
6015 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6016 /* Fields below are only available in SQLite 3.10.0 and later */
6017 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6021 ** CAPI3REF: Virtual Table Scan Flags
6023 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6026 ** CAPI3REF: Virtual Table Constraint Operator Codes
6028 ** These macros defined the allowed values for the
6029 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
6030 ** an operator that is part of a constraint term in the wHERE clause of
6031 ** a query that uses a [virtual table].
6033 #define SQLITE_INDEX_CONSTRAINT_EQ 2
6034 #define SQLITE_INDEX_CONSTRAINT_GT 4
6035 #define SQLITE_INDEX_CONSTRAINT_LE 8
6036 #define SQLITE_INDEX_CONSTRAINT_LT 16
6037 #define SQLITE_INDEX_CONSTRAINT_GE 32
6038 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
6039 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
6040 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
6041 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6044 ** CAPI3REF: Register A Virtual Table Implementation
6047 ** ^These routines are used to register a new [virtual table module] name.
6048 ** ^Module names must be registered before
6049 ** creating a new [virtual table] using the module and before using a
6050 ** preexisting [virtual table] for the module.
6052 ** ^The module name is registered on the [database connection] specified
6053 ** by the first parameter. ^The name of the module is given by the
6054 ** second parameter. ^The third parameter is a pointer to
6055 ** the implementation of the [virtual table module]. ^The fourth
6056 ** parameter is an arbitrary client data pointer that is passed through
6057 ** into the [xCreate] and [xConnect] methods of the virtual table module
6058 ** when a new virtual table is be being created or reinitialized.
6060 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6061 ** is a pointer to a destructor for the pClientData. ^SQLite will
6062 ** invoke the destructor function (if it is not NULL) when SQLite
6063 ** no longer needs the pClientData pointer. ^The destructor will also
6064 ** be invoked if the call to sqlite3_create_module_v2() fails.
6065 ** ^The sqlite3_create_module()
6066 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
6069 SQLITE_API int sqlite3_create_module(
6070 sqlite3 *db, /* SQLite connection to register module with */
6071 const char *zName, /* Name of the module */
6072 const sqlite3_module *p, /* Methods for the module */
6073 void *pClientData /* Client data for xCreate/xConnect */
6075 SQLITE_API int sqlite3_create_module_v2(
6076 sqlite3 *db, /* SQLite connection to register module with */
6077 const char *zName, /* Name of the module */
6078 const sqlite3_module *p, /* Methods for the module */
6079 void *pClientData, /* Client data for xCreate/xConnect */
6080 void(*xDestroy)(void*) /* Module destructor function */
6084 ** CAPI3REF: Virtual Table Instance Object
6085 ** KEYWORDS: sqlite3_vtab
6087 ** Every [virtual table module] implementation uses a subclass
6088 ** of this object to describe a particular instance
6089 ** of the [virtual table]. Each subclass will
6090 ** be tailored to the specific needs of the module implementation.
6091 ** The purpose of this superclass is to define certain fields that are
6092 ** common to all module implementations.
6094 ** ^Virtual tables methods can set an error message by assigning a
6095 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6096 ** take care that any prior string is freed by a call to [sqlite3_free()]
6097 ** prior to assigning a new string to zErrMsg. ^After the error message
6098 ** is delivered up to the client application, the string will be automatically
6099 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6101 struct sqlite3_vtab {
6102 const sqlite3_module *pModule; /* The module for this virtual table */
6103 int nRef; /* Number of open cursors */
6104 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6105 /* Virtual table implementations will typically add additional fields */
6109 ** CAPI3REF: Virtual Table Cursor Object
6110 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6112 ** Every [virtual table module] implementation uses a subclass of the
6113 ** following structure to describe cursors that point into the
6114 ** [virtual table] and are used
6115 ** to loop through the virtual table. Cursors are created using the
6116 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6117 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6118 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6119 ** of the module. Each module implementation will define
6120 ** the content of a cursor structure to suit its own needs.
6122 ** This superclass exists in order to define fields of the cursor that
6123 ** are common to all implementations.
6125 struct sqlite3_vtab_cursor {
6126 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6127 /* Virtual table implementations will typically add additional fields */
6131 ** CAPI3REF: Declare The Schema Of A Virtual Table
6133 ** ^The [xCreate] and [xConnect] methods of a
6134 ** [virtual table module] call this interface
6135 ** to declare the format (the names and datatypes of the columns) of
6136 ** the virtual tables they implement.
6138 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6141 ** CAPI3REF: Overload A Function For A Virtual Table
6144 ** ^(Virtual tables can provide alternative implementations of functions
6145 ** using the [xFindFunction] method of the [virtual table module].
6146 ** But global versions of those functions
6147 ** must exist in order to be overloaded.)^
6149 ** ^(This API makes sure a global version of a function with a particular
6150 ** name and number of parameters exists. If no such function exists
6151 ** before this API is called, a new function is created.)^ ^The implementation
6152 ** of the new function always causes an exception to be thrown. So
6153 ** the new function is not good for anything by itself. Its only
6154 ** purpose is to be a placeholder function that can be overloaded
6155 ** by a [virtual table].
6157 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6160 ** The interface to the virtual-table mechanism defined above (back up
6161 ** to a comment remarkably similar to this one) is currently considered
6162 ** to be experimental. The interface might change in incompatible ways.
6163 ** If this is a problem for you, do not use the interface at this time.
6165 ** When the virtual-table mechanism stabilizes, we will declare the
6166 ** interface fixed, support it indefinitely, and remove this comment.
6170 ** CAPI3REF: A Handle To An Open BLOB
6171 ** KEYWORDS: {BLOB handle} {BLOB handles}
6173 ** An instance of this object represents an open BLOB on which
6174 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6175 ** ^Objects of this type are created by [sqlite3_blob_open()]
6176 ** and destroyed by [sqlite3_blob_close()].
6177 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6178 ** can be used to read or write small subsections of the BLOB.
6179 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6181 typedef struct sqlite3_blob sqlite3_blob;
6184 ** CAPI3REF: Open A BLOB For Incremental I/O
6186 ** CONSTRUCTOR: sqlite3_blob
6188 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6189 ** in row iRow, column zColumn, table zTable in database zDb;
6190 ** in other words, the same BLOB that would be selected by:
6193 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6196 ** ^(Parameter zDb is not the filename that contains the database, but
6197 ** rather the symbolic name of the database. For attached databases, this is
6198 ** the name that appears after the AS keyword in the [ATTACH] statement.
6199 ** For the main database file, the database name is "main". For TEMP
6200 ** tables, the database name is "temp".)^
6202 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
6203 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
6204 ** read-only access.
6206 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6207 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6208 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6209 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6210 ** on *ppBlob after this function it returns.
6212 ** This function fails with SQLITE_ERROR if any of the following are true:
6214 ** <li> ^(Database zDb does not exist)^,
6215 ** <li> ^(Table zTable does not exist within database zDb)^,
6216 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6217 ** <li> ^(Column zColumn does not exist)^,
6218 ** <li> ^(Row iRow is not present in the table)^,
6219 ** <li> ^(The specified column of row iRow contains a value that is not
6220 ** a TEXT or BLOB value)^,
6221 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6222 ** constraint and the blob is being opened for read/write access)^,
6223 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6224 ** column zColumn is part of a [child key] definition and the blob is
6225 ** being opened for read/write access)^.
6228 ** ^Unless it returns SQLITE_MISUSE, this function sets the
6229 ** [database connection] error code and message accessible via
6230 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6232 ** A BLOB referenced by sqlite3_blob_open() may be read using the
6233 ** [sqlite3_blob_read()] interface and modified by using
6234 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6235 ** different row of the same table using the [sqlite3_blob_reopen()]
6236 ** interface. However, the column, table, or database of a [BLOB handle]
6237 ** cannot be changed after the [BLOB handle] is opened.
6239 ** ^(If the row that a BLOB handle points to is modified by an
6240 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6241 ** then the BLOB handle is marked as "expired".
6242 ** This is true if any column of the row is changed, even a column
6243 ** other than the one the BLOB handle is open on.)^
6244 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6245 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6246 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
6247 ** rolled back by the expiration of the BLOB. Such changes will eventually
6248 ** commit if the transaction continues to completion.)^
6250 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6251 ** the opened blob. ^The size of a blob may not be changed by this
6252 ** interface. Use the [UPDATE] SQL command to change the size of a
6255 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6256 ** and the built-in [zeroblob] SQL function may be used to create a
6257 ** zero-filled blob to read or write using the incremental-blob interface.
6259 ** To avoid a resource leak, every open [BLOB handle] should eventually
6260 ** be released by a call to [sqlite3_blob_close()].
6262 ** See also: [sqlite3_blob_close()],
6263 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6264 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6266 SQLITE_API int sqlite3_blob_open(
6270 const char *zColumn,
6273 sqlite3_blob **ppBlob
6277 ** CAPI3REF: Move a BLOB Handle to a New Row
6278 ** METHOD: sqlite3_blob
6280 ** ^This function is used to move an existing [BLOB handle] so that it points
6281 ** to a different row of the same database table. ^The new row is identified
6282 ** by the rowid value passed as the second argument. Only the row can be
6283 ** changed. ^The database, table and column on which the blob handle is open
6284 ** remain the same. Moving an existing [BLOB handle] to a new row is
6285 ** faster than closing the existing handle and opening a new one.
6287 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6288 ** it must exist and there must be either a blob or text value stored in
6289 ** the nominated column.)^ ^If the new row is not present in the table, or if
6290 ** it does not contain a blob or text value, or if another error occurs, an
6291 ** SQLite error code is returned and the blob handle is considered aborted.
6292 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6293 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6294 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6295 ** always returns zero.
6297 ** ^This function sets the database handle error code and message.
6299 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6302 ** CAPI3REF: Close A BLOB Handle
6303 ** DESTRUCTOR: sqlite3_blob
6305 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6306 ** unconditionally. Even if this routine returns an error code, the
6307 ** handle is still closed.)^
6309 ** ^If the blob handle being closed was opened for read-write access, and if
6310 ** the database is in auto-commit mode and there are no other open read-write
6311 ** blob handles or active write statements, the current transaction is
6312 ** committed. ^If an error occurs while committing the transaction, an error
6313 ** code is returned and the transaction rolled back.
6315 ** Calling this function with an argument that is not a NULL pointer or an
6316 ** open blob handle results in undefined behaviour. ^Calling this routine
6317 ** with a null pointer (such as would be returned by a failed call to
6318 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6319 ** is passed a valid open blob handle, the values returned by the
6320 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6322 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6325 ** CAPI3REF: Return The Size Of An Open BLOB
6326 ** METHOD: sqlite3_blob
6328 ** ^Returns the size in bytes of the BLOB accessible via the
6329 ** successfully opened [BLOB handle] in its only argument. ^The
6330 ** incremental blob I/O routines can only read or overwriting existing
6331 ** blob content; they cannot change the size of a blob.
6333 ** This routine only works on a [BLOB handle] which has been created
6334 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6335 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6336 ** to this routine results in undefined and probably undesirable behavior.
6338 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6341 ** CAPI3REF: Read Data From A BLOB Incrementally
6342 ** METHOD: sqlite3_blob
6344 ** ^(This function is used to read data from an open [BLOB handle] into a
6345 ** caller-supplied buffer. N bytes of data are copied into buffer Z
6346 ** from the open BLOB, starting at offset iOffset.)^
6348 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6349 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6350 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
6351 ** ^The size of the blob (and hence the maximum value of N+iOffset)
6352 ** can be determined using the [sqlite3_blob_bytes()] interface.
6354 ** ^An attempt to read from an expired [BLOB handle] fails with an
6355 ** error code of [SQLITE_ABORT].
6357 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6358 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6360 ** This routine only works on a [BLOB handle] which has been created
6361 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6362 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6363 ** to this routine results in undefined and probably undesirable behavior.
6365 ** See also: [sqlite3_blob_write()].
6367 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6370 ** CAPI3REF: Write Data Into A BLOB Incrementally
6371 ** METHOD: sqlite3_blob
6373 ** ^(This function is used to write data into an open [BLOB handle] from a
6374 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
6375 ** into the open BLOB, starting at offset iOffset.)^
6377 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6378 ** Otherwise, an [error code] or an [extended error code] is returned.)^
6379 ** ^Unless SQLITE_MISUSE is returned, this function sets the
6380 ** [database connection] error code and message accessible via
6381 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6383 ** ^If the [BLOB handle] passed as the first argument was not opened for
6384 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6385 ** this function returns [SQLITE_READONLY].
6387 ** This function may only modify the contents of the BLOB; it is
6388 ** not possible to increase the size of a BLOB using this API.
6389 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
6390 ** [SQLITE_ERROR] is returned and no data is written. The size of the
6391 ** BLOB (and hence the maximum value of N+iOffset) can be determined
6392 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6393 ** than zero [SQLITE_ERROR] is returned and no data is written.
6395 ** ^An attempt to write to an expired [BLOB handle] fails with an
6396 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6397 ** before the [BLOB handle] expired are not rolled back by the
6398 ** expiration of the handle, though of course those changes might
6399 ** have been overwritten by the statement that expired the BLOB handle
6400 ** or by other independent statements.
6402 ** This routine only works on a [BLOB handle] which has been created
6403 ** by a prior successful call to [sqlite3_blob_open()] and which has not
6404 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6405 ** to this routine results in undefined and probably undesirable behavior.
6407 ** See also: [sqlite3_blob_read()].
6409 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6412 ** CAPI3REF: Virtual File System Objects
6414 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6415 ** that SQLite uses to interact
6416 ** with the underlying operating system. Most SQLite builds come with a
6417 ** single default VFS that is appropriate for the host computer.
6418 ** New VFSes can be registered and existing VFSes can be unregistered.
6419 ** The following interfaces are provided.
6421 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6422 ** ^Names are case sensitive.
6423 ** ^Names are zero-terminated UTF-8 strings.
6424 ** ^If there is no match, a NULL pointer is returned.
6425 ** ^If zVfsName is NULL then the default VFS is returned.
6427 ** ^New VFSes are registered with sqlite3_vfs_register().
6428 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6429 ** ^The same VFS can be registered multiple times without injury.
6430 ** ^To make an existing VFS into the default VFS, register it again
6431 ** with the makeDflt flag set. If two different VFSes with the
6432 ** same name are registered, the behavior is undefined. If a
6433 ** VFS is registered with a name that is NULL or an empty string,
6434 ** then the behavior is undefined.
6436 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6437 ** ^(If the default VFS is unregistered, another VFS is chosen as
6438 ** the default. The choice for the new VFS is arbitrary.)^
6440 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6441 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6442 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6445 ** CAPI3REF: Mutexes
6447 ** The SQLite core uses these routines for thread
6448 ** synchronization. Though they are intended for internal
6449 ** use by SQLite, code that links against SQLite is
6450 ** permitted to use any of these routines.
6452 ** The SQLite source code contains multiple implementations
6453 ** of these mutex routines. An appropriate implementation
6454 ** is selected automatically at compile-time. The following
6455 ** implementations are available in the SQLite core:
6458 ** <li> SQLITE_MUTEX_PTHREADS
6459 ** <li> SQLITE_MUTEX_W32
6460 ** <li> SQLITE_MUTEX_NOOP
6463 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
6464 ** that does no real locking and is appropriate for use in
6465 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6466 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6469 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6470 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6471 ** implementation is included with the library. In this case the
6472 ** application must supply a custom mutex implementation using the
6473 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6474 ** before calling sqlite3_initialize() or any other public sqlite3_
6475 ** function that calls sqlite3_initialize().
6477 ** ^The sqlite3_mutex_alloc() routine allocates a new
6478 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6479 ** routine returns NULL if it is unable to allocate the requested
6480 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
6481 ** integer constants:
6484 ** <li> SQLITE_MUTEX_FAST
6485 ** <li> SQLITE_MUTEX_RECURSIVE
6486 ** <li> SQLITE_MUTEX_STATIC_MASTER
6487 ** <li> SQLITE_MUTEX_STATIC_MEM
6488 ** <li> SQLITE_MUTEX_STATIC_OPEN
6489 ** <li> SQLITE_MUTEX_STATIC_PRNG
6490 ** <li> SQLITE_MUTEX_STATIC_LRU
6491 ** <li> SQLITE_MUTEX_STATIC_PMEM
6492 ** <li> SQLITE_MUTEX_STATIC_APP1
6493 ** <li> SQLITE_MUTEX_STATIC_APP2
6494 ** <li> SQLITE_MUTEX_STATIC_APP3
6495 ** <li> SQLITE_MUTEX_STATIC_VFS1
6496 ** <li> SQLITE_MUTEX_STATIC_VFS2
6497 ** <li> SQLITE_MUTEX_STATIC_VFS3
6500 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6501 ** cause sqlite3_mutex_alloc() to create
6502 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6503 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6504 ** The mutex implementation does not need to make a distinction
6505 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6506 ** not want to. SQLite will only request a recursive mutex in
6507 ** cases where it really needs one. If a faster non-recursive mutex
6508 ** implementation is available on the host platform, the mutex subsystem
6509 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
6511 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6512 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6513 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
6514 ** used by the current version of SQLite. Future versions of SQLite
6515 ** may add additional static mutexes. Static mutexes are for internal
6516 ** use by SQLite only. Applications that use SQLite mutexes should
6517 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6518 ** SQLITE_MUTEX_RECURSIVE.
6520 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6521 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6522 ** returns a different mutex on every call. ^For the static
6523 ** mutex types, the same mutex is returned on every call that has
6524 ** the same type number.
6526 ** ^The sqlite3_mutex_free() routine deallocates a previously
6527 ** allocated dynamic mutex. Attempting to deallocate a static
6528 ** mutex results in undefined behavior.
6530 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6531 ** to enter a mutex. ^If another thread is already within the mutex,
6532 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6533 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6534 ** upon successful entry. ^(Mutexes created using
6535 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6536 ** In such cases, the
6537 ** mutex must be exited an equal number of times before another thread
6538 ** can enter.)^ If the same thread tries to enter any mutex other
6539 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6541 ** ^(Some systems (for example, Windows 95) do not support the operation
6542 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6543 ** will always return SQLITE_BUSY. The SQLite core only ever uses
6544 ** sqlite3_mutex_try() as an optimization so this is acceptable
6547 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
6548 ** previously entered by the same thread. The behavior
6549 ** is undefined if the mutex is not currently entered by the
6550 ** calling thread or is not currently allocated.
6552 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6553 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6554 ** behave as no-ops.
6556 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6558 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
6559 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
6560 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
6561 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
6562 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
6565 ** CAPI3REF: Mutex Methods Object
6567 ** An instance of this structure defines the low-level routines
6568 ** used to allocate and use mutexes.
6570 ** Usually, the default mutex implementations provided by SQLite are
6571 ** sufficient, however the application has the option of substituting a custom
6572 ** implementation for specialized deployments or systems for which SQLite
6573 ** does not provide a suitable implementation. In this case, the application
6574 ** creates and populates an instance of this structure to pass
6575 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6576 ** Additionally, an instance of this structure can be used as an
6577 ** output variable when querying the system for the current mutex
6578 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6580 ** ^The xMutexInit method defined by this structure is invoked as
6581 ** part of system initialization by the sqlite3_initialize() function.
6582 ** ^The xMutexInit routine is called by SQLite exactly once for each
6583 ** effective call to [sqlite3_initialize()].
6585 ** ^The xMutexEnd method defined by this structure is invoked as
6586 ** part of system shutdown by the sqlite3_shutdown() function. The
6587 ** implementation of this method is expected to release all outstanding
6588 ** resources obtained by the mutex methods implementation, especially
6589 ** those obtained by the xMutexInit method. ^The xMutexEnd()
6590 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6592 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6593 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6594 ** xMutexNotheld) implement the following interfaces (respectively):
6597 ** <li> [sqlite3_mutex_alloc()] </li>
6598 ** <li> [sqlite3_mutex_free()] </li>
6599 ** <li> [sqlite3_mutex_enter()] </li>
6600 ** <li> [sqlite3_mutex_try()] </li>
6601 ** <li> [sqlite3_mutex_leave()] </li>
6602 ** <li> [sqlite3_mutex_held()] </li>
6603 ** <li> [sqlite3_mutex_notheld()] </li>
6606 ** The only difference is that the public sqlite3_XXX functions enumerated
6607 ** above silently ignore any invocations that pass a NULL pointer instead
6608 ** of a valid mutex handle. The implementations of the methods defined
6609 ** by this structure are not required to handle this case, the results
6610 ** of passing a NULL pointer instead of a valid mutex handle are undefined
6611 ** (i.e. it is acceptable to provide an implementation that segfaults if
6612 ** it is passed a NULL pointer).
6614 ** The xMutexInit() method must be threadsafe. It must be harmless to
6615 ** invoke xMutexInit() multiple times within the same process and without
6616 ** intervening calls to xMutexEnd(). Second and subsequent calls to
6617 ** xMutexInit() must be no-ops.
6619 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6620 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
6621 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
6622 ** memory allocation for a fast or recursive mutex.
6624 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6625 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6626 ** If xMutexInit fails in any way, it is expected to clean up after itself
6627 ** prior to returning.
6629 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6630 struct sqlite3_mutex_methods {
6631 int (*xMutexInit)(void);
6632 int (*xMutexEnd)(void);
6633 sqlite3_mutex *(*xMutexAlloc)(int);
6634 void (*xMutexFree)(sqlite3_mutex *);
6635 void (*xMutexEnter)(sqlite3_mutex *);
6636 int (*xMutexTry)(sqlite3_mutex *);
6637 void (*xMutexLeave)(sqlite3_mutex *);
6638 int (*xMutexHeld)(sqlite3_mutex *);
6639 int (*xMutexNotheld)(sqlite3_mutex *);
6643 ** CAPI3REF: Mutex Verification Routines
6645 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6646 ** are intended for use inside assert() statements. The SQLite core
6647 ** never uses these routines except inside an assert() and applications
6648 ** are advised to follow the lead of the core. The SQLite core only
6649 ** provides implementations for these routines when it is compiled
6650 ** with the SQLITE_DEBUG flag. External mutex implementations
6651 ** are only required to provide these routines if SQLITE_DEBUG is
6652 ** defined and if NDEBUG is not defined.
6654 ** These routines should return true if the mutex in their argument
6655 ** is held or not held, respectively, by the calling thread.
6657 ** The implementation is not required to provide versions of these
6658 ** routines that actually work. If the implementation does not provide working
6659 ** versions of these routines, it should at least provide stubs that always
6660 ** return true so that one does not get spurious assertion failures.
6662 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
6663 ** the routine should return 1. This seems counter-intuitive since
6664 ** clearly the mutex cannot be held if it does not exist. But
6665 ** the reason the mutex does not exist is because the build is not
6666 ** using mutexes. And we do not want the assert() containing the
6667 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
6668 ** the appropriate thing to do. The sqlite3_mutex_notheld()
6669 ** interface should also return 1 when given a NULL pointer.
6672 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
6673 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
6677 ** CAPI3REF: Mutex Types
6679 ** The [sqlite3_mutex_alloc()] interface takes a single argument
6680 ** which is one of these integer constants.
6682 ** The set of static mutexes may change from one SQLite release to the
6683 ** next. Applications that override the built-in mutex logic must be
6684 ** prepared to accommodate additional static mutexes.
6686 #define SQLITE_MUTEX_FAST 0
6687 #define SQLITE_MUTEX_RECURSIVE 1
6688 #define SQLITE_MUTEX_STATIC_MASTER 2
6689 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
6690 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
6691 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
6692 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
6693 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
6694 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
6695 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
6696 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
6697 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
6698 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
6699 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
6700 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
6701 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
6704 ** CAPI3REF: Retrieve the mutex for a database connection
6707 ** ^This interface returns a pointer the [sqlite3_mutex] object that
6708 ** serializes access to the [database connection] given in the argument
6709 ** when the [threading mode] is Serialized.
6710 ** ^If the [threading mode] is Single-thread or Multi-thread then this
6711 ** routine returns a NULL pointer.
6713 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
6716 ** CAPI3REF: Low-Level Control Of Database Files
6719 ** ^The [sqlite3_file_control()] interface makes a direct call to the
6720 ** xFileControl method for the [sqlite3_io_methods] object associated
6721 ** with a particular database identified by the second argument. ^The
6722 ** name of the database is "main" for the main database or "temp" for the
6723 ** TEMP database, or the name that appears after the AS keyword for
6724 ** databases that are added using the [ATTACH] SQL command.
6725 ** ^A NULL pointer can be used in place of "main" to refer to the
6726 ** main database file.
6727 ** ^The third and fourth parameters to this routine
6728 ** are passed directly through to the second and third parameters of
6729 ** the xFileControl method. ^The return value of the xFileControl
6730 ** method becomes the return value of this routine.
6732 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6733 ** a pointer to the underlying [sqlite3_file] object to be written into
6734 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
6735 ** case is a short-circuit path which does not actually invoke the
6736 ** underlying sqlite3_io_methods.xFileControl method.
6738 ** ^If the second parameter (zDbName) does not match the name of any
6739 ** open database file, then SQLITE_ERROR is returned. ^This error
6740 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
6741 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
6742 ** also return SQLITE_ERROR. There is no way to distinguish between
6743 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6744 ** xFileControl method.
6746 ** See also: [SQLITE_FCNTL_LOCKSTATE]
6748 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6751 ** CAPI3REF: Testing Interface
6753 ** ^The sqlite3_test_control() interface is used to read out internal
6754 ** state of SQLite and to inject faults into SQLite for testing
6755 ** purposes. ^The first parameter is an operation code that determines
6756 ** the number, meaning, and operation of all subsequent parameters.
6758 ** This interface is not for use by applications. It exists solely
6759 ** for verifying the correct operation of the SQLite library. Depending
6760 ** on how the SQLite library is compiled, this interface might not exist.
6762 ** The details of the operation codes, their meanings, the parameters
6763 ** they take, and what they do are all subject to change without notice.
6764 ** Unlike most of the SQLite API, this function is not guaranteed to
6765 ** operate consistently from one release to the next.
6767 SQLITE_API int sqlite3_test_control(int op, ...);
6770 ** CAPI3REF: Testing Interface Operation Codes
6772 ** These constants are the valid operation code parameters used
6773 ** as the first argument to [sqlite3_test_control()].
6775 ** These parameters and their meanings are subject to change
6776 ** without notice. These values are for testing purposes only.
6777 ** Applications should not use any of these parameters or the
6778 ** [sqlite3_test_control()] interface.
6780 #define SQLITE_TESTCTRL_FIRST 5
6781 #define SQLITE_TESTCTRL_PRNG_SAVE 5
6782 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
6783 #define SQLITE_TESTCTRL_PRNG_RESET 7
6784 #define SQLITE_TESTCTRL_BITVEC_TEST 8
6785 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
6786 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6787 #define SQLITE_TESTCTRL_PENDING_BYTE 11
6788 #define SQLITE_TESTCTRL_ASSERT 12
6789 #define SQLITE_TESTCTRL_ALWAYS 13
6790 #define SQLITE_TESTCTRL_RESERVE 14
6791 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
6792 #define SQLITE_TESTCTRL_ISKEYWORD 16
6793 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17
6794 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
6795 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
6796 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
6797 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
6798 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
6799 #define SQLITE_TESTCTRL_BYTEORDER 22
6800 #define SQLITE_TESTCTRL_ISINIT 23
6801 #define SQLITE_TESTCTRL_SORTER_MMAP 24
6802 #define SQLITE_TESTCTRL_IMPOSTER 25
6803 #define SQLITE_TESTCTRL_LAST 25
6806 ** CAPI3REF: SQLite Runtime Status
6808 ** ^These interfaces are used to retrieve runtime status information
6809 ** about the performance of SQLite, and optionally to reset various
6810 ** highwater marks. ^The first argument is an integer code for
6811 ** the specific parameter to measure. ^(Recognized integer codes
6812 ** are of the form [status parameters | SQLITE_STATUS_...].)^
6813 ** ^The current value of the parameter is returned into *pCurrent.
6814 ** ^The highest recorded value is returned in *pHighwater. ^If the
6815 ** resetFlag is true, then the highest record value is reset after
6816 ** *pHighwater is written. ^(Some parameters do not record the highest
6817 ** value. For those parameters
6818 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
6819 ** ^(Other parameters record only the highwater mark and not the current
6820 ** value. For these latter parameters nothing is written into *pCurrent.)^
6822 ** ^The sqlite3_status() and sqlite3_status64() routines return
6823 ** SQLITE_OK on success and a non-zero [error code] on failure.
6825 ** If either the current value or the highwater mark is too large to
6826 ** be represented by a 32-bit integer, then the values returned by
6827 ** sqlite3_status() are undefined.
6829 ** See also: [sqlite3_db_status()]
6831 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6832 SQLITE_API int sqlite3_status64(
6834 sqlite3_int64 *pCurrent,
6835 sqlite3_int64 *pHighwater,
6841 ** CAPI3REF: Status Parameters
6842 ** KEYWORDS: {status parameters}
6844 ** These integer constants designate various run-time status parameters
6845 ** that can be returned by [sqlite3_status()].
6848 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6849 ** <dd>This parameter is the current amount of memory checked out
6850 ** using [sqlite3_malloc()], either directly or indirectly. The
6851 ** figure includes calls made to [sqlite3_malloc()] by the application
6852 ** and internal memory usage by the SQLite library. Scratch memory
6853 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6854 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6855 ** this parameter. The amount returned is the sum of the allocation
6856 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6858 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6859 ** <dd>This parameter records the largest memory allocation request
6860 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6861 ** internal equivalents). Only the value returned in the
6862 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6863 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6865 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6866 ** <dd>This parameter records the number of separate memory allocations
6867 ** currently checked out.</dd>)^
6869 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6870 ** <dd>This parameter returns the number of pages used out of the
6871 ** [pagecache memory allocator] that was configured using
6872 ** [SQLITE_CONFIG_PAGECACHE]. The
6873 ** value returned is in pages, not in bytes.</dd>)^
6875 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6876 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6877 ** <dd>This parameter returns the number of bytes of page cache
6878 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6879 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
6880 ** returned value includes allocations that overflowed because they
6881 ** where too large (they were larger than the "sz" parameter to
6882 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6883 ** no space was left in the page cache.</dd>)^
6885 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6886 ** <dd>This parameter records the largest memory allocation request
6887 ** handed to [pagecache memory allocator]. Only the value returned in the
6888 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6889 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6891 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6892 ** <dd>This parameter returns the number of allocations used out of the
6893 ** [scratch memory allocator] configured using
6894 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
6895 ** in bytes. Since a single thread may only have one scratch allocation
6896 ** outstanding at time, this parameter also reports the number of threads
6897 ** using scratch memory at the same time.</dd>)^
6899 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6900 ** <dd>This parameter returns the number of bytes of scratch memory
6901 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6902 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6903 ** returned include overflows because the requested allocation was too
6904 ** larger (that is, because the requested allocation was larger than the
6905 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6906 ** slots were available.
6909 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6910 ** <dd>This parameter records the largest memory allocation request
6911 ** handed to [scratch memory allocator]. Only the value returned in the
6912 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6913 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6915 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6916 ** <dd>The *pHighwater parameter records the deepest parser stack.
6917 ** The *pCurrent value is undefined. The *pHighwater value is only
6918 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6921 ** New status parameters may be added from time to time.
6923 #define SQLITE_STATUS_MEMORY_USED 0
6924 #define SQLITE_STATUS_PAGECACHE_USED 1
6925 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6926 #define SQLITE_STATUS_SCRATCH_USED 3
6927 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6928 #define SQLITE_STATUS_MALLOC_SIZE 5
6929 #define SQLITE_STATUS_PARSER_STACK 6
6930 #define SQLITE_STATUS_PAGECACHE_SIZE 7
6931 #define SQLITE_STATUS_SCRATCH_SIZE 8
6932 #define SQLITE_STATUS_MALLOC_COUNT 9
6935 ** CAPI3REF: Database Connection Status
6938 ** ^This interface is used to retrieve runtime status information
6939 ** about a single [database connection]. ^The first argument is the
6940 ** database connection object to be interrogated. ^The second argument
6941 ** is an integer constant, taken from the set of
6942 ** [SQLITE_DBSTATUS options], that
6943 ** determines the parameter to interrogate. The set of
6944 ** [SQLITE_DBSTATUS options] is likely
6945 ** to grow in future releases of SQLite.
6947 ** ^The current value of the requested parameter is written into *pCur
6948 ** and the highest instantaneous value is written into *pHiwtr. ^If
6949 ** the resetFlg is true, then the highest instantaneous value is
6950 ** reset back down to the current value.
6952 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6953 ** non-zero [error code] on failure.
6955 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6957 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6960 ** CAPI3REF: Status Parameters for database connections
6961 ** KEYWORDS: {SQLITE_DBSTATUS options}
6963 ** These constants are the available integer "verbs" that can be passed as
6964 ** the second argument to the [sqlite3_db_status()] interface.
6966 ** New verbs may be added in future releases of SQLite. Existing verbs
6967 ** might be discontinued. Applications should check the return code from
6968 ** [sqlite3_db_status()] to make sure that the call worked.
6969 ** The [sqlite3_db_status()] interface will return a non-zero error code
6970 ** if a discontinued or unsupported verb is invoked.
6973 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6974 ** <dd>This parameter returns the number of lookaside memory slots currently
6975 ** checked out.</dd>)^
6977 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6978 ** <dd>This parameter returns the number malloc attempts that were
6979 ** satisfied using lookaside memory. Only the high-water value is meaningful;
6980 ** the current value is always zero.)^
6982 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6983 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6984 ** <dd>This parameter returns the number malloc attempts that might have
6985 ** been satisfied using lookaside memory but failed due to the amount of
6986 ** memory requested being larger than the lookaside slot size.
6987 ** Only the high-water value is meaningful;
6988 ** the current value is always zero.)^
6990 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6991 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6992 ** <dd>This parameter returns the number malloc attempts that might have
6993 ** been satisfied using lookaside memory but failed due to all lookaside
6994 ** memory already being in use.
6995 ** Only the high-water value is meaningful;
6996 ** the current value is always zero.)^
6998 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6999 ** <dd>This parameter returns the approximate number of bytes of heap
7000 ** memory used by all pager caches associated with the database connection.)^
7001 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7003 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7004 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7005 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7006 ** pager cache is shared between two or more connections the bytes of heap
7007 ** memory used by that pager cache is divided evenly between the attached
7008 ** connections.)^ In other words, if none of the pager caches associated
7009 ** with the database connection are shared, this request returns the same
7010 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7011 ** shared, the value returned by this call will be smaller than that returned
7012 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7013 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7015 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7016 ** <dd>This parameter returns the approximate number of bytes of heap
7017 ** memory used to store the schema for all databases associated
7018 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7019 ** ^The full amount of memory used by the schemas is reported, even if the
7020 ** schema memory is shared with other database connections due to
7021 ** [shared cache mode] being enabled.
7022 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7024 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7025 ** <dd>This parameter returns the approximate number of bytes of heap
7026 ** and lookaside memory used by all prepared statements associated with
7027 ** the database connection.)^
7028 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7031 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7032 ** <dd>This parameter returns the number of pager cache hits that have
7033 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7037 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7038 ** <dd>This parameter returns the number of pager cache misses that have
7039 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7043 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7044 ** <dd>This parameter returns the number of dirty cache entries that have
7045 ** been written to disk. Specifically, the number of pages written to the
7046 ** wal file in wal mode databases, or the number of pages written to the
7047 ** database file in rollback mode databases. Any pages written as part of
7048 ** transaction rollback or database recovery operations are not included.
7049 ** If an IO or other error occurs while writing a page to disk, the effect
7050 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7051 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7054 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7055 ** <dd>This parameter returns zero for the current value if and only if
7056 ** all foreign key constraints (deferred or immediate) have been
7057 ** resolved.)^ ^The highwater mark is always 0.
7061 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7062 #define SQLITE_DBSTATUS_CACHE_USED 1
7063 #define SQLITE_DBSTATUS_SCHEMA_USED 2
7064 #define SQLITE_DBSTATUS_STMT_USED 3
7065 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7066 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7067 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7068 #define SQLITE_DBSTATUS_CACHE_HIT 7
7069 #define SQLITE_DBSTATUS_CACHE_MISS 8
7070 #define SQLITE_DBSTATUS_CACHE_WRITE 9
7071 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
7072 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7073 #define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */
7077 ** CAPI3REF: Prepared Statement Status
7078 ** METHOD: sqlite3_stmt
7080 ** ^(Each prepared statement maintains various
7081 ** [SQLITE_STMTSTATUS counters] that measure the number
7082 ** of times it has performed specific operations.)^ These counters can
7083 ** be used to monitor the performance characteristics of the prepared
7084 ** statements. For example, if the number of table steps greatly exceeds
7085 ** the number of table searches or result rows, that would tend to indicate
7086 ** that the prepared statement is using a full table scan rather than
7089 ** ^(This interface is used to retrieve and reset counter values from
7090 ** a [prepared statement]. The first argument is the prepared statement
7091 ** object to be interrogated. The second argument
7092 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7093 ** to be interrogated.)^
7094 ** ^The current value of the requested counter is returned.
7095 ** ^If the resetFlg is true, then the counter is reset to zero after this
7096 ** interface call returns.
7098 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
7100 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7103 ** CAPI3REF: Status Parameters for prepared statements
7104 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7106 ** These preprocessor macros define integer codes that name counter
7107 ** values associated with the [sqlite3_stmt_status()] interface.
7108 ** The meanings of the various counters are as follows:
7111 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7112 ** <dd>^This is the number of times that SQLite has stepped forward in
7113 ** a table as part of a full table scan. Large numbers for this counter
7114 ** may indicate opportunities for performance improvement through
7115 ** careful use of indices.</dd>
7117 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7118 ** <dd>^This is the number of sort operations that have occurred.
7119 ** A non-zero value in this counter may indicate an opportunity to
7120 ** improvement performance through careful use of indices.</dd>
7122 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7123 ** <dd>^This is the number of rows inserted into transient indices that
7124 ** were created automatically in order to help joins run faster.
7125 ** A non-zero value in this counter may indicate an opportunity to
7126 ** improvement performance by adding permanent indices that do not
7127 ** need to be reinitialized each time the statement is run.</dd>
7129 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7130 ** <dd>^This is the number of virtual machine operations executed
7131 ** by the prepared statement if that number is less than or equal
7132 ** to 2147483647. The number of virtual machine operations can be
7133 ** used as a proxy for the total work done by the prepared statement.
7134 ** If the number of virtual machine operations exceeds 2147483647
7135 ** then the value returned by this statement status code is undefined.
7139 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7140 #define SQLITE_STMTSTATUS_SORT 2
7141 #define SQLITE_STMTSTATUS_AUTOINDEX 3
7142 #define SQLITE_STMTSTATUS_VM_STEP 4
7145 ** CAPI3REF: Custom Page Cache Object
7147 ** The sqlite3_pcache type is opaque. It is implemented by
7148 ** the pluggable module. The SQLite core has no knowledge of
7149 ** its size or internal structure and never deals with the
7150 ** sqlite3_pcache object except by holding and passing pointers
7153 ** See [sqlite3_pcache_methods2] for additional information.
7155 typedef struct sqlite3_pcache sqlite3_pcache;
7158 ** CAPI3REF: Custom Page Cache Object
7160 ** The sqlite3_pcache_page object represents a single page in the
7161 ** page cache. The page cache will allocate instances of this
7162 ** object. Various methods of the page cache use pointers to instances
7163 ** of this object as parameters or as their return value.
7165 ** See [sqlite3_pcache_methods2] for additional information.
7167 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7168 struct sqlite3_pcache_page {
7169 void *pBuf; /* The content of the page */
7170 void *pExtra; /* Extra information associated with the page */
7174 ** CAPI3REF: Application Defined Page Cache.
7175 ** KEYWORDS: {page cache}
7177 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7178 ** register an alternative page cache implementation by passing in an
7179 ** instance of the sqlite3_pcache_methods2 structure.)^
7180 ** In many applications, most of the heap memory allocated by
7181 ** SQLite is used for the page cache.
7182 ** By implementing a
7183 ** custom page cache using this API, an application can better control
7184 ** the amount of memory consumed by SQLite, the way in which
7185 ** that memory is allocated and released, and the policies used to
7186 ** determine exactly which parts of a database file are cached and for
7189 ** The alternative page cache mechanism is an
7190 ** extreme measure that is only needed by the most demanding applications.
7191 ** The built-in page cache is recommended for most uses.
7193 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7194 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7195 ** the application may discard the parameter after the call to
7196 ** [sqlite3_config()] returns.)^
7198 ** [[the xInit() page cache method]]
7199 ** ^(The xInit() method is called once for each effective
7200 ** call to [sqlite3_initialize()])^
7201 ** (usually only once during the lifetime of the process). ^(The xInit()
7202 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7203 ** The intent of the xInit() method is to set up global data structures
7204 ** required by the custom page cache implementation.
7205 ** ^(If the xInit() method is NULL, then the
7206 ** built-in default page cache is used instead of the application defined
7209 ** [[the xShutdown() page cache method]]
7210 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
7211 ** It can be used to clean up
7212 ** any outstanding resources before process shutdown, if required.
7213 ** ^The xShutdown() method may be NULL.
7215 ** ^SQLite automatically serializes calls to the xInit method,
7216 ** so the xInit method need not be threadsafe. ^The
7217 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
7218 ** not need to be threadsafe either. All other methods must be threadsafe
7219 ** in multithreaded applications.
7221 ** ^SQLite will never invoke xInit() more than once without an intervening
7222 ** call to xShutdown().
7224 ** [[the xCreate() page cache methods]]
7225 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
7226 ** SQLite will typically create one cache instance for each open database file,
7227 ** though this is not guaranteed. ^The
7228 ** first parameter, szPage, is the size in bytes of the pages that must
7229 ** be allocated by the cache. ^szPage will always a power of two. ^The
7230 ** second parameter szExtra is a number of bytes of extra storage
7231 ** associated with each page cache entry. ^The szExtra parameter will
7232 ** a number less than 250. SQLite will use the
7233 ** extra szExtra bytes on each page to store metadata about the underlying
7234 ** database page on disk. The value passed into szExtra depends
7235 ** on the SQLite version, the target platform, and how SQLite was compiled.
7236 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7237 ** created will be used to cache database pages of a file stored on disk, or
7238 ** false if it is used for an in-memory database. The cache implementation
7239 ** does not have to do anything special based with the value of bPurgeable;
7240 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7241 ** never invoke xUnpin() except to deliberately delete a page.
7242 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7243 ** false will always have the "discard" flag set to true.
7244 ** ^Hence, a cache created with bPurgeable false will
7245 ** never contain any unpinned pages.
7247 ** [[the xCachesize() page cache method]]
7248 ** ^(The xCachesize() method may be called at any time by SQLite to set the
7249 ** suggested maximum cache-size (number of pages stored by) the cache
7250 ** instance passed as the first argument. This is the value configured using
7251 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7252 ** parameter, the implementation is not required to do anything with this
7253 ** value; it is advisory only.
7255 ** [[the xPagecount() page cache methods]]
7256 ** The xPagecount() method must return the number of pages currently
7257 ** stored in the cache, both pinned and unpinned.
7259 ** [[the xFetch() page cache methods]]
7260 ** The xFetch() method locates a page in the cache and returns a pointer to
7261 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7262 ** The pBuf element of the returned sqlite3_pcache_page object will be a
7263 ** pointer to a buffer of szPage bytes used to store the content of a
7264 ** single database page. The pExtra element of sqlite3_pcache_page will be
7265 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
7266 ** for each entry in the page cache.
7268 ** The page to be fetched is determined by the key. ^The minimum key value
7269 ** is 1. After it has been retrieved using xFetch, the page is considered
7272 ** If the requested page is already in the page cache, then the page cache
7273 ** implementation must return a pointer to the page buffer with its content
7274 ** intact. If the requested page is not already in the cache, then the
7275 ** cache implementation should use the value of the createFlag
7276 ** parameter to help it determined what action to take:
7278 ** <table border=1 width=85% align=center>
7279 ** <tr><th> createFlag <th> Behavior when page is not already in cache
7280 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7281 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7282 ** Otherwise return NULL.
7283 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7284 ** NULL if allocating a new page is effectively impossible.
7287 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7288 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
7289 ** failed.)^ In between the to xFetch() calls, SQLite may
7290 ** attempt to unpin one or more cache pages by spilling the content of
7291 ** pinned pages to disk and synching the operating system disk cache.
7293 ** [[the xUnpin() page cache method]]
7294 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7295 ** as its second argument. If the third parameter, discard, is non-zero,
7296 ** then the page must be evicted from the cache.
7297 ** ^If the discard parameter is
7298 ** zero, then the page may be discarded or retained at the discretion of
7299 ** page cache implementation. ^The page cache implementation
7300 ** may choose to evict unpinned pages at any time.
7302 ** The cache must not perform any reference counting. A single
7303 ** call to xUnpin() unpins the page regardless of the number of prior calls
7306 ** [[the xRekey() page cache methods]]
7307 ** The xRekey() method is used to change the key value associated with the
7308 ** page passed as the second argument. If the cache
7309 ** previously contains an entry associated with newKey, it must be
7310 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7313 ** When SQLite calls the xTruncate() method, the cache must discard all
7314 ** existing cache entries with page numbers (keys) greater than or equal
7315 ** to the value of the iLimit parameter passed to xTruncate(). If any
7316 ** of these pages are pinned, they are implicitly unpinned, meaning that
7317 ** they can be safely discarded.
7319 ** [[the xDestroy() page cache method]]
7320 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7321 ** All resources associated with the specified cache should be freed. ^After
7322 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7323 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7326 ** [[the xShrink() page cache method]]
7327 ** ^SQLite invokes the xShrink() method when it wants the page cache to
7328 ** free up as much of heap memory as possible. The page cache implementation
7329 ** is not obligated to free any memory, but well-behaved implementations should
7332 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7333 struct sqlite3_pcache_methods2 {
7336 int (*xInit)(void*);
7337 void (*xShutdown)(void*);
7338 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7339 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7340 int (*xPagecount)(sqlite3_pcache*);
7341 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7342 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7343 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7344 unsigned oldKey, unsigned newKey);
7345 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7346 void (*xDestroy)(sqlite3_pcache*);
7347 void (*xShrink)(sqlite3_pcache*);
7351 ** This is the obsolete pcache_methods object that has now been replaced
7352 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
7353 ** retained in the header file for backwards compatibility only.
7355 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7356 struct sqlite3_pcache_methods {
7358 int (*xInit)(void*);
7359 void (*xShutdown)(void*);
7360 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7361 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7362 int (*xPagecount)(sqlite3_pcache*);
7363 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7364 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7365 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7366 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7367 void (*xDestroy)(sqlite3_pcache*);
7372 ** CAPI3REF: Online Backup Object
7374 ** The sqlite3_backup object records state information about an ongoing
7375 ** online backup operation. ^The sqlite3_backup object is created by
7376 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
7377 ** [sqlite3_backup_finish()].
7379 ** See Also: [Using the SQLite Online Backup API]
7381 typedef struct sqlite3_backup sqlite3_backup;
7384 ** CAPI3REF: Online Backup API.
7386 ** The backup API copies the content of one database into another.
7387 ** It is useful either for creating backups of databases or
7388 ** for copying in-memory databases to or from persistent files.
7390 ** See Also: [Using the SQLite Online Backup API]
7392 ** ^SQLite holds a write transaction open on the destination database file
7393 ** for the duration of the backup operation.
7394 ** ^The source database is read-locked only while it is being read;
7395 ** it is not locked continuously for the entire backup operation.
7396 ** ^Thus, the backup may be performed on a live source database without
7397 ** preventing other database connections from
7398 ** reading or writing to the source database while the backup is underway.
7400 ** ^(To perform a backup operation:
7402 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
7404 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
7405 ** the data between the two databases, and finally
7406 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
7407 ** associated with the backup operation.
7409 ** There should be exactly one call to sqlite3_backup_finish() for each
7410 ** successful call to sqlite3_backup_init().
7412 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
7414 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
7415 ** [database connection] associated with the destination database
7416 ** and the database name, respectively.
7417 ** ^The database name is "main" for the main database, "temp" for the
7418 ** temporary database, or the name specified after the AS keyword in
7419 ** an [ATTACH] statement for an attached database.
7420 ** ^The S and M arguments passed to
7421 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
7422 ** and database name of the source database, respectively.
7423 ** ^The source and destination [database connections] (parameters S and D)
7424 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
7427 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
7428 ** there is already a read or read-write transaction open on the
7429 ** destination database.
7431 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
7432 ** returned and an error code and error message are stored in the
7433 ** destination [database connection] D.
7434 ** ^The error code and message for the failed call to sqlite3_backup_init()
7435 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
7436 ** [sqlite3_errmsg16()] functions.
7437 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
7438 ** [sqlite3_backup] object.
7439 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
7440 ** sqlite3_backup_finish() functions to perform the specified backup
7443 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
7445 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
7446 ** the source and destination databases specified by [sqlite3_backup] object B.
7447 ** ^If N is negative, all remaining source pages are copied.
7448 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
7449 ** are still more pages to be copied, then the function returns [SQLITE_OK].
7450 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
7451 ** from source to destination, then it returns [SQLITE_DONE].
7452 ** ^If an error occurs while running sqlite3_backup_step(B,N),
7453 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
7454 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
7455 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
7456 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
7458 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
7460 ** <li> the destination database was opened read-only, or
7461 ** <li> the destination database is using write-ahead-log journaling
7462 ** and the destination and source page sizes differ, or
7463 ** <li> the destination database is an in-memory database and the
7464 ** destination and source page sizes differ.
7467 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
7468 ** the [sqlite3_busy_handler | busy-handler function]
7469 ** is invoked (if one is specified). ^If the
7470 ** busy-handler returns non-zero before the lock is available, then
7471 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
7472 ** sqlite3_backup_step() can be retried later. ^If the source
7473 ** [database connection]
7474 ** is being used to write to the source database when sqlite3_backup_step()
7475 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
7476 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
7477 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
7478 ** [SQLITE_READONLY] is returned, then
7479 ** there is no point in retrying the call to sqlite3_backup_step(). These
7480 ** errors are considered fatal.)^ The application must accept
7481 ** that the backup operation has failed and pass the backup operation handle
7482 ** to the sqlite3_backup_finish() to release associated resources.
7484 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
7485 ** on the destination file. ^The exclusive lock is not released until either
7486 ** sqlite3_backup_finish() is called or the backup operation is complete
7487 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
7488 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
7489 ** lasts for the duration of the sqlite3_backup_step() call.
7490 ** ^Because the source database is not locked between calls to
7491 ** sqlite3_backup_step(), the source database may be modified mid-way
7492 ** through the backup process. ^If the source database is modified by an
7493 ** external process or via a database connection other than the one being
7494 ** used by the backup operation, then the backup will be automatically
7495 ** restarted by the next call to sqlite3_backup_step(). ^If the source
7496 ** database is modified by the using the same database connection as is used
7497 ** by the backup operation, then the backup database is automatically
7498 ** updated at the same time.
7500 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
7502 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
7503 ** application wishes to abandon the backup operation, the application
7504 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
7505 ** ^The sqlite3_backup_finish() interfaces releases all
7506 ** resources associated with the [sqlite3_backup] object.
7507 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
7508 ** active write-transaction on the destination database is rolled back.
7509 ** The [sqlite3_backup] object is invalid
7510 ** and may not be used following a call to sqlite3_backup_finish().
7512 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
7513 ** sqlite3_backup_step() errors occurred, regardless or whether or not
7514 ** sqlite3_backup_step() completed.
7515 ** ^If an out-of-memory condition or IO error occurred during any prior
7516 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
7517 ** sqlite3_backup_finish() returns the corresponding [error code].
7519 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
7520 ** is not a permanent error and does not affect the return value of
7521 ** sqlite3_backup_finish().
7523 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
7524 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
7526 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
7527 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
7528 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
7529 ** in the source database at the conclusion of the most recent
7530 ** sqlite3_backup_step().
7531 ** ^(The values returned by these functions are only updated by
7532 ** sqlite3_backup_step(). If the source database is modified in a way that
7533 ** changes the size of the source database or the number of pages remaining,
7534 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
7535 ** and sqlite3_backup_remaining() until after the next
7536 ** sqlite3_backup_step().)^
7538 ** <b>Concurrent Usage of Database Handles</b>
7540 ** ^The source [database connection] may be used by the application for other
7541 ** purposes while a backup operation is underway or being initialized.
7542 ** ^If SQLite is compiled and configured to support threadsafe database
7543 ** connections, then the source database connection may be used concurrently
7544 ** from within other threads.
7546 ** However, the application must guarantee that the destination
7547 ** [database connection] is not passed to any other API (by any thread) after
7548 ** sqlite3_backup_init() is called and before the corresponding call to
7549 ** sqlite3_backup_finish(). SQLite does not currently check to see
7550 ** if the application incorrectly accesses the destination [database connection]
7551 ** and so no error code is reported, but the operations may malfunction
7552 ** nevertheless. Use of the destination database connection while a
7553 ** backup is in progress might also also cause a mutex deadlock.
7555 ** If running in [shared cache mode], the application must
7556 ** guarantee that the shared cache used by the destination database
7557 ** is not accessed while the backup is running. In practice this means
7558 ** that the application must guarantee that the disk file being
7559 ** backed up to is not accessed by any connection within the process,
7560 ** not just the specific connection that was passed to sqlite3_backup_init().
7562 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
7563 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
7564 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
7565 ** APIs are not strictly speaking threadsafe. If they are invoked at the
7566 ** same time as another thread is invoking sqlite3_backup_step() it is
7567 ** possible that they return invalid values.
7569 SQLITE_API sqlite3_backup *sqlite3_backup_init(
7570 sqlite3 *pDest, /* Destination database handle */
7571 const char *zDestName, /* Destination database name */
7572 sqlite3 *pSource, /* Source database handle */
7573 const char *zSourceName /* Source database name */
7575 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
7576 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
7577 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
7578 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
7581 ** CAPI3REF: Unlock Notification
7584 ** ^When running in shared-cache mode, a database operation may fail with
7585 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7586 ** individual tables within the shared-cache cannot be obtained. See
7587 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7588 ** ^This API may be used to register a callback that SQLite will invoke
7589 ** when the connection currently holding the required lock relinquishes it.
7590 ** ^This API is only available if the library was compiled with the
7591 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7593 ** See Also: [Using the SQLite Unlock Notification Feature].
7595 ** ^Shared-cache locks are released when a database connection concludes
7596 ** its current transaction, either by committing it or rolling it back.
7598 ** ^When a connection (known as the blocked connection) fails to obtain a
7599 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7600 ** identity of the database connection (the blocking connection) that
7601 ** has locked the required resource is stored internally. ^After an
7602 ** application receives an SQLITE_LOCKED error, it may call the
7603 ** sqlite3_unlock_notify() method with the blocked connection handle as
7604 ** the first argument to register for a callback that will be invoked
7605 ** when the blocking connections current transaction is concluded. ^The
7606 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7607 ** call that concludes the blocking connections transaction.
7609 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7610 ** there is a chance that the blocking connection will have already
7611 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7612 ** If this happens, then the specified callback is invoked immediately,
7613 ** from within the call to sqlite3_unlock_notify().)^
7615 ** ^If the blocked connection is attempting to obtain a write-lock on a
7616 ** shared-cache table, and more than one other connection currently holds
7617 ** a read-lock on the same table, then SQLite arbitrarily selects one of
7618 ** the other connections to use as the blocking connection.
7620 ** ^(There may be at most one unlock-notify callback registered by a
7621 ** blocked connection. If sqlite3_unlock_notify() is called when the
7622 ** blocked connection already has a registered unlock-notify callback,
7623 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7624 ** called with a NULL pointer as its second argument, then any existing
7625 ** unlock-notify callback is canceled. ^The blocked connections
7626 ** unlock-notify callback may also be canceled by closing the blocked
7627 ** connection using [sqlite3_close()].
7629 ** The unlock-notify callback is not reentrant. If an application invokes
7630 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
7631 ** crash or deadlock may be the result.
7633 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7634 ** returns SQLITE_OK.
7636 ** <b>Callback Invocation Details</b>
7638 ** When an unlock-notify callback is registered, the application provides a
7639 ** single void* pointer that is passed to the callback when it is invoked.
7640 ** However, the signature of the callback function allows SQLite to pass
7641 ** it an array of void* context pointers. The first argument passed to
7642 ** an unlock-notify callback is a pointer to an array of void* pointers,
7643 ** and the second is the number of entries in the array.
7645 ** When a blocking connections transaction is concluded, there may be
7646 ** more than one blocked connection that has registered for an unlock-notify
7647 ** callback. ^If two or more such blocked connections have specified the
7648 ** same callback function, then instead of invoking the callback function
7649 ** multiple times, it is invoked once with the set of void* context pointers
7650 ** specified by the blocked connections bundled together into an array.
7651 ** This gives the application an opportunity to prioritize any actions
7652 ** related to the set of unblocked database connections.
7654 ** <b>Deadlock Detection</b>
7656 ** Assuming that after registering for an unlock-notify callback a
7657 ** database waits for the callback to be issued before taking any further
7658 ** action (a reasonable assumption), then using this API may cause the
7659 ** application to deadlock. For example, if connection X is waiting for
7660 ** connection Y's transaction to be concluded, and similarly connection
7661 ** Y is waiting on connection X's transaction, then neither connection
7662 ** will proceed and the system may remain deadlocked indefinitely.
7664 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7665 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
7666 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7667 ** unlock-notify callback is registered. The system is said to be in
7668 ** a deadlocked state if connection A has registered for an unlock-notify
7669 ** callback on the conclusion of connection B's transaction, and connection
7670 ** B has itself registered for an unlock-notify callback when connection
7671 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
7672 ** the system is also considered to be deadlocked if connection B has
7673 ** registered for an unlock-notify callback on the conclusion of connection
7674 ** C's transaction, where connection C is waiting on connection A. ^Any
7675 ** number of levels of indirection are allowed.
7677 ** <b>The "DROP TABLE" Exception</b>
7679 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7680 ** always appropriate to call sqlite3_unlock_notify(). There is however,
7681 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7682 ** SQLite checks if there are any currently executing SELECT statements
7683 ** that belong to the same connection. If there are, SQLITE_LOCKED is
7684 ** returned. In this case there is no "blocking connection", so invoking
7685 ** sqlite3_unlock_notify() results in the unlock-notify callback being
7686 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
7687 ** or "DROP INDEX" query, an infinite loop might be the result.
7689 ** One way around this problem is to check the extended error code returned
7690 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7691 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7692 ** the special "DROP TABLE/INDEX" case, the extended error code is just
7695 SQLITE_API int sqlite3_unlock_notify(
7696 sqlite3 *pBlocked, /* Waiting connection */
7697 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
7698 void *pNotifyArg /* Argument to pass to xNotify */
7703 ** CAPI3REF: String Comparison
7705 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7706 ** and extensions to compare the contents of two buffers containing UTF-8
7707 ** strings in a case-independent fashion, using the same definition of "case
7708 ** independence" that SQLite uses internally when comparing identifiers.
7710 SQLITE_API int sqlite3_stricmp(const char *, const char *);
7711 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
7714 ** CAPI3REF: String Globbing
7716 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
7717 ** string X matches the [GLOB] pattern P.
7718 ** ^The definition of [GLOB] pattern matching used in
7719 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7720 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
7721 ** is case sensitive.
7723 ** Note that this routine returns zero on a match and non-zero if the strings
7724 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7726 ** See also: [sqlite3_strlike()].
7728 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
7731 ** CAPI3REF: String LIKE Matching
7733 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
7734 ** string X matches the [LIKE] pattern P with escape character E.
7735 ** ^The definition of [LIKE] pattern matching used in
7736 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
7737 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
7738 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
7739 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
7740 ** insensitive - equivalent upper and lower case ASCII characters match
7743 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
7744 ** only ASCII characters are case folded.
7746 ** Note that this routine returns zero on a match and non-zero if the strings
7747 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7749 ** See also: [sqlite3_strglob()].
7751 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
7754 ** CAPI3REF: Error Logging Interface
7756 ** ^The [sqlite3_log()] interface writes a message into the [error log]
7757 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7758 ** ^If logging is enabled, the zFormat string and subsequent arguments are
7759 ** used with [sqlite3_snprintf()] to generate the final output string.
7761 ** The sqlite3_log() interface is intended for use by extensions such as
7762 ** virtual tables, collating functions, and SQL functions. While there is
7763 ** nothing to prevent an application from calling sqlite3_log(), doing so
7764 ** is considered bad form.
7766 ** The zFormat string must not be NULL.
7768 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7769 ** will not use dynamically allocated memory. The log message is stored in
7770 ** a fixed-length buffer on the stack. If the log message is longer than
7771 ** a few hundred characters, it will be truncated to the length of the
7774 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
7777 ** CAPI3REF: Write-Ahead Log Commit Hook
7780 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
7781 ** is invoked each time data is committed to a database in wal mode.
7783 ** ^(The callback is invoked by SQLite after the commit has taken place and
7784 ** the associated write-lock on the database released)^, so the implementation
7785 ** may read, write or [checkpoint] the database as required.
7787 ** ^The first parameter passed to the callback function when it is invoked
7788 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
7789 ** registering the callback. ^The second is a copy of the database handle.
7790 ** ^The third parameter is the name of the database that was written to -
7791 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7792 ** is the number of pages currently in the write-ahead log file,
7793 ** including those that were just committed.
7795 ** The callback function should normally return [SQLITE_OK]. ^If an error
7796 ** code is returned, that error will propagate back up through the
7797 ** SQLite code base to cause the statement that provoked the callback
7798 ** to report an error, though the commit will have still occurred. If the
7799 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7800 ** that does not correspond to any valid SQLite error code, the results
7803 ** A single database handle may have at most a single write-ahead log callback
7804 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7805 ** previously registered write-ahead log callback. ^Note that the
7806 ** [sqlite3_wal_autocheckpoint()] interface and the
7807 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7808 ** overwrite any prior [sqlite3_wal_hook()] settings.
7810 SQLITE_API void *sqlite3_wal_hook(
7812 int(*)(void *,sqlite3*,const char*,int),
7817 ** CAPI3REF: Configure an auto-checkpoint
7820 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7821 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
7822 ** to automatically [checkpoint]
7823 ** after committing a transaction if there are N or
7824 ** more frames in the [write-ahead log] file. ^Passing zero or
7825 ** a negative value as the nFrame parameter disables automatic
7826 ** checkpoints entirely.
7828 ** ^The callback registered by this function replaces any existing callback
7829 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
7830 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7831 ** configured by this function.
7833 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7836 ** ^Checkpoints initiated by this mechanism are
7837 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
7839 ** ^Every new [database connection] defaults to having the auto-checkpoint
7840 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7841 ** pages. The use of this interface
7842 ** is only necessary if the default setting is found to be suboptimal
7843 ** for a particular application.
7845 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7848 ** CAPI3REF: Checkpoint a database
7851 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
7852 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
7854 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
7855 ** [write-ahead log] for database X on [database connection] D to be
7856 ** transferred into the database file and for the write-ahead log to
7857 ** be reset. See the [checkpointing] documentation for addition
7860 ** This interface used to be the only way to cause a checkpoint to
7861 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
7862 ** interface was added. This interface is retained for backwards
7863 ** compatibility and as a convenience for applications that need to manually
7864 ** start a callback but which do not need the full power (and corresponding
7865 ** complication) of [sqlite3_wal_checkpoint_v2()].
7867 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7870 ** CAPI3REF: Checkpoint a database
7873 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
7874 ** operation on database X of [database connection] D in mode M. Status
7875 ** information is written back into integers pointed to by L and C.)^
7876 ** ^(The M parameter must be a valid [checkpoint mode]:)^
7879 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7880 ** ^Checkpoint as many frames as possible without waiting for any database
7881 ** readers or writers to finish, then sync the database file if all frames
7882 ** in the log were checkpointed. ^The [busy-handler callback]
7883 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
7884 ** ^On the other hand, passive mode might leave the checkpoint unfinished
7885 ** if there are concurrent readers or writers.
7887 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
7888 ** ^This mode blocks (it invokes the
7889 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
7890 ** database writer and all readers are reading from the most recent database
7891 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
7892 ** database file. ^This mode blocks new database writers while it is pending,
7893 ** but new database readers are allowed to continue unimpeded.
7895 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7896 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
7897 ** that after checkpointing the log file it blocks (calls the
7898 ** [busy-handler callback])
7899 ** until all readers are reading from the database file only. ^This ensures
7900 ** that the next writer will restart the log file from the beginning.
7901 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
7902 ** database writer attempts while it is pending, but does not impede readers.
7904 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
7905 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
7906 ** addition that it also truncates the log file to zero bytes just prior
7907 ** to a successful return.
7910 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
7911 ** the log file or to -1 if the checkpoint could not run because
7912 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
7913 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
7914 ** log file (including any that were already checkpointed before the function
7915 ** was called) or to -1 if the checkpoint could not run due to an error or
7916 ** because the database is not in WAL mode. ^Note that upon successful
7917 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
7918 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
7920 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
7921 ** any other process is running a checkpoint operation at the same time, the
7922 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
7923 ** busy-handler configured, it will not be invoked in this case.
7925 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
7926 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
7927 ** obtained immediately, and a busy-handler is configured, it is invoked and
7928 ** the writer lock retried until either the busy-handler returns 0 or the lock
7929 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
7930 ** database readers as described above. ^If the busy-handler returns 0 before
7931 ** the writer lock is obtained or while waiting for database readers, the
7932 ** checkpoint operation proceeds from that point in the same way as
7933 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7934 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
7936 ** ^If parameter zDb is NULL or points to a zero length string, then the
7937 ** specified operation is attempted on all WAL databases [attached] to
7938 ** [database connection] db. In this case the
7939 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
7940 ** an SQLITE_BUSY error is encountered when processing one or more of the
7941 ** attached WAL databases, the operation is still attempted on any remaining
7942 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
7943 ** error occurs while processing an attached database, processing is abandoned
7944 ** and the error code is returned to the caller immediately. ^If no error
7945 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7946 ** databases, SQLITE_OK is returned.
7948 ** ^If database zDb is the name of an attached database that is not in WAL
7949 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
7950 ** zDb is not NULL (or a zero length string) and is not the name of any
7951 ** attached database, SQLITE_ERROR is returned to the caller.
7953 ** ^Unless it returns SQLITE_MISUSE,
7954 ** the sqlite3_wal_checkpoint_v2() interface
7955 ** sets the error information that is queried by
7956 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
7958 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
7961 SQLITE_API int sqlite3_wal_checkpoint_v2(
7962 sqlite3 *db, /* Database handle */
7963 const char *zDb, /* Name of attached database (or NULL) */
7964 int eMode, /* SQLITE_CHECKPOINT_* value */
7965 int *pnLog, /* OUT: Size of WAL log in frames */
7966 int *pnCkpt /* OUT: Total number of frames checkpointed */
7970 ** CAPI3REF: Checkpoint Mode Values
7971 ** KEYWORDS: {checkpoint mode}
7973 ** These constants define all valid values for the "checkpoint mode" passed
7974 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
7975 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
7976 ** meaning of each of these checkpoint modes.
7978 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
7979 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
7980 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
7981 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
7984 ** CAPI3REF: Virtual Table Interface Configuration
7986 ** This function may be called by either the [xConnect] or [xCreate] method
7987 ** of a [virtual table] implementation to configure
7988 ** various facets of the virtual table interface.
7990 ** If this interface is invoked outside the context of an xConnect or
7991 ** xCreate virtual table method then the behavior is undefined.
7993 ** At present, there is only one option that may be configured using
7994 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
7995 ** may be added in the future.
7997 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8000 ** CAPI3REF: Virtual Table Configuration Options
8002 ** These macros define the various options to the
8003 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
8004 ** can use to customize and optimize their behavior.
8007 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8008 ** <dd>Calls of the form
8009 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8010 ** where X is an integer. If X is zero, then the [virtual table] whose
8011 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8012 ** support constraints. In this configuration (which is the default) if
8013 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8014 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8015 ** specified as part of the users SQL statement, regardless of the actual
8016 ** ON CONFLICT mode specified.
8018 ** If X is non-zero, then the virtual table implementation guarantees
8019 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8020 ** any modifications to internal or persistent data structures have been made.
8021 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8022 ** is able to roll back a statement or database transaction, and abandon
8023 ** or continue processing the current SQL statement as appropriate.
8024 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8025 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8028 ** Virtual table implementations that are required to handle OR REPLACE
8029 ** must do so within the [xUpdate] method. If a call to the
8030 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8031 ** CONFLICT policy is REPLACE, the virtual table implementation should
8032 ** silently replace the appropriate rows within the xUpdate callback and
8033 ** return SQLITE_OK. Or, if this is not possible, it may return
8034 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8035 ** constraint handling.
8038 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8041 ** CAPI3REF: Determine The Virtual Table Conflict Policy
8043 ** This function may only be called from within a call to the [xUpdate] method
8044 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8045 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8046 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8047 ** of the SQL statement that triggered the call to the [xUpdate] method of the
8050 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8053 ** CAPI3REF: Conflict resolution modes
8054 ** KEYWORDS: {conflict resolution mode}
8056 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
8057 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
8058 ** is for the SQL statement being evaluated.
8060 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
8061 ** return value from the [sqlite3_set_authorizer()] callback and that
8062 ** [SQLITE_ABORT] is also a [result code].
8064 #define SQLITE_ROLLBACK 1
8065 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8066 #define SQLITE_FAIL 3
8067 /* #define SQLITE_ABORT 4 // Also an error code */
8068 #define SQLITE_REPLACE 5
8071 ** CAPI3REF: Prepared Statement Scan Status Opcodes
8072 ** KEYWORDS: {scanstatus options}
8074 ** The following constants can be used for the T parameter to the
8075 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8076 ** different metric for sqlite3_stmt_scanstatus() to return.
8078 ** When the value returned to V is a string, space to hold that string is
8079 ** managed by the prepared statement S and will be automatically freed when
8083 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8084 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8085 ** set to the total number of times that the X-th loop has run.</dd>
8087 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8088 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8089 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
8091 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8092 ** <dd>^The "double" variable pointed to by the T parameter will be set to the
8093 ** query planner's estimate for the average number of rows output from each
8094 ** iteration of the X-th loop. If the query planner's estimates was accurate,
8095 ** then this value will approximate the quotient NVISIT/NLOOP and the
8096 ** product of this value for all prior loops with the same SELECTID will
8097 ** be the NLOOP value for the current loop.
8099 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8100 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8101 ** to a zero-terminated UTF-8 string containing the name of the index or table
8102 ** used for the X-th loop.
8104 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8105 ** <dd>^The "const char *" variable pointed to by the T parameter will be set
8106 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8107 ** description for the X-th loop.
8109 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8110 ** <dd>^The "int" variable pointed to by the T parameter will be set to the
8111 ** "select-id" for the X-th loop. The select-id identifies which query or
8112 ** subquery the loop is part of. The main query has a select-id of zero.
8113 ** The select-id is the same value as is output in the first column
8114 ** of an [EXPLAIN QUERY PLAN] query.
8117 #define SQLITE_SCANSTAT_NLOOP 0
8118 #define SQLITE_SCANSTAT_NVISIT 1
8119 #define SQLITE_SCANSTAT_EST 2
8120 #define SQLITE_SCANSTAT_NAME 3
8121 #define SQLITE_SCANSTAT_EXPLAIN 4
8122 #define SQLITE_SCANSTAT_SELECTID 5
8125 ** CAPI3REF: Prepared Statement Scan Status
8126 ** METHOD: sqlite3_stmt
8128 ** This interface returns information about the predicted and measured
8129 ** performance for pStmt. Advanced applications can use this
8130 ** interface to compare the predicted and the measured performance and
8131 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8133 ** Since this interface is expected to be rarely used, it is only
8134 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8135 ** compile-time option.
8137 ** The "iScanStatusOp" parameter determines which status information to return.
8138 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8139 ** of this interface is undefined.
8140 ** ^The requested measurement is written into a variable pointed to by
8141 ** the "pOut" parameter.
8142 ** Parameter "idx" identifies the specific loop to retrieve statistics for.
8143 ** Loops are numbered starting from zero. ^If idx is out of range - less than
8144 ** zero or greater than or equal to the total number of loops used to implement
8145 ** the statement - a non-zero value is returned and the variable that pOut
8146 ** points to is unchanged.
8148 ** ^Statistics might not be available for all loops in all statements. ^In cases
8149 ** where there exist loops with no available statistics, this function behaves
8150 ** as if the loop did not exist - it returns non-zero and leave the variable
8151 ** that pOut points to unchanged.
8153 ** See also: [sqlite3_stmt_scanstatus_reset()]
8155 SQLITE_API int sqlite3_stmt_scanstatus(
8156 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8157 int idx, /* Index of loop to report on */
8158 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8159 void *pOut /* Result written here */
8163 ** CAPI3REF: Zero Scan-Status Counters
8164 ** METHOD: sqlite3_stmt
8166 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8168 ** This API is only available if the library is built with pre-processor
8169 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8171 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8174 ** CAPI3REF: Flush caches to disk mid-transaction
8176 ** ^If a write-transaction is open on [database connection] D when the
8177 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8178 ** pages in the pager-cache that are not currently in use are written out
8179 ** to disk. A dirty page may be in use if a database cursor created by an
8180 ** active SQL statement is reading from it, or if it is page 1 of a database
8181 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8182 ** interface flushes caches for all schemas - "main", "temp", and
8183 ** any [attached] databases.
8185 ** ^If this function needs to obtain extra database locks before dirty pages
8186 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
8187 ** immediately and there is a busy-handler callback configured, it is invoked
8188 ** in the usual manner. ^If the required lock still cannot be obtained, then
8189 ** the database is skipped and an attempt made to flush any dirty pages
8190 ** belonging to the next (if any) database. ^If any databases are skipped
8191 ** because locks cannot be obtained, but no other error occurs, this
8192 ** function returns SQLITE_BUSY.
8194 ** ^If any other error occurs while flushing dirty pages to disk (for
8195 ** example an IO error or out-of-memory condition), then processing is
8196 ** abandoned and an SQLite [error code] is returned to the caller immediately.
8198 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8200 ** ^This function does not set the database handle error code or message
8201 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8203 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8206 ** CAPI3REF: The pre-update hook.
8208 ** ^These interfaces are only available if SQLite is compiled using the
8209 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8211 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8212 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8213 ** on a database table.
8214 ** ^At most one preupdate hook may be registered at a time on a single
8215 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8216 ** the previous setting.
8217 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8218 ** with a NULL pointer as the second parameter.
8219 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8220 ** the first parameter to callbacks.
8222 ** ^The preupdate hook only fires for changes to real database tables; the
8223 ** preupdate hook is not invoked for changes to [virtual tables] or to
8224 ** system tables like sqlite_master or sqlite_stat1.
8226 ** ^The second parameter to the preupdate callback is a pointer to
8227 ** the [database connection] that registered the preupdate hook.
8228 ** ^The third parameter to the preupdate callback is one of the constants
8229 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8230 ** kind of update operation that is about to occur.
8231 ** ^(The fourth parameter to the preupdate callback is the name of the
8232 ** database within the database connection that is being modified. This
8233 ** will be "main" for the main database or "temp" for TEMP tables or
8234 ** the name given after the AS keyword in the [ATTACH] statement for attached
8236 ** ^The fifth parameter to the preupdate callback is the name of the
8237 ** table that is being modified.
8239 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
8240 ** parameter passed to the preupdate callback is the initial [rowid] of the
8241 ** row being modified or deleted. For an INSERT operation on a rowid table,
8242 ** or any operation on a WITHOUT ROWID table, the value of the sixth
8243 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8244 ** seventh parameter is the final rowid value of the row being inserted
8245 ** or updated. The value of the seventh parameter passed to the callback
8246 ** function is not defined for operations on WITHOUT ROWID tables, or for
8247 ** INSERT operations on rowid tables.
8249 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8250 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8251 ** provide additional information about a preupdate event. These routines
8252 ** may only be called from within a preupdate callback. Invoking any of
8253 ** these routines from outside of a preupdate callback or with a
8254 ** [database connection] pointer that is different from the one supplied
8255 ** to the preupdate callback results in undefined and probably undesirable
8258 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8259 ** in the row that is being inserted, updated, or deleted.
8261 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8262 ** a [protected sqlite3_value] that contains the value of the Nth column of
8263 ** the table row before it is updated. The N parameter must be between 0
8264 ** and one less than the number of columns or the behavior will be
8265 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8266 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8267 ** behavior is undefined. The [sqlite3_value] that P points to
8268 ** will be destroyed when the preupdate callback returns.
8270 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8271 ** a [protected sqlite3_value] that contains the value of the Nth column of
8272 ** the table row after it is updated. The N parameter must be between 0
8273 ** and one less than the number of columns or the behavior will be
8274 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8275 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8276 ** behavior is undefined. The [sqlite3_value] that P points to
8277 ** will be destroyed when the preupdate callback returns.
8279 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8280 ** callback was invoked as a result of a direct insert, update, or delete
8281 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
8282 ** triggers; or 2 for changes resulting from triggers called by top-level
8283 ** triggers; and so forth.
8285 ** See also: [sqlite3_update_hook()]
8287 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
8288 SQLITE_API void *sqlite3_preupdate_hook(
8291 void *pCtx, /* Copy of third arg to preupdate_hook() */
8292 sqlite3 *db, /* Database handle */
8293 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8294 char const *zDb, /* Database name */
8295 char const *zName, /* Table name */
8296 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8297 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8301 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8302 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
8303 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
8304 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8308 ** CAPI3REF: Low-level system error code
8310 ** ^Attempt to return the underlying operating system error code or error
8311 ** number that caused the most recent I/O error or failure to open a file.
8312 ** The return value is OS-dependent. For example, on unix systems, after
8313 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
8314 ** called to get back the underlying "errno" that caused the problem, such
8315 ** as ENOSPC, EAUTH, EISDIR, and so forth.
8317 SQLITE_API int sqlite3_system_errno(sqlite3*);
8320 ** CAPI3REF: Database Snapshot
8321 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
8324 ** An instance of the snapshot object records the state of a [WAL mode]
8325 ** database for some specific point in history.
8327 ** In [WAL mode], multiple [database connections] that are open on the
8328 ** same database file can each be reading a different historical version
8329 ** of the database file. When a [database connection] begins a read
8330 ** transaction, that connection sees an unchanging copy of the database
8331 ** as it existed for the point in time when the transaction first started.
8332 ** Subsequent changes to the database from other connections are not seen
8333 ** by the reader until a new read transaction is started.
8335 ** The sqlite3_snapshot object records state information about an historical
8336 ** version of the database file so that it is possible to later open a new read
8337 ** transaction that sees that historical version of the database rather than
8338 ** the most recent version.
8340 ** The constructor for this object is [sqlite3_snapshot_get()]. The
8341 ** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
8342 ** to an historical snapshot (if possible). The destructor for
8343 ** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
8345 typedef struct sqlite3_snapshot {
8346 unsigned char hidden[48];
8350 ** CAPI3REF: Record A Database Snapshot
8353 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
8354 ** new [sqlite3_snapshot] object that records the current state of
8355 ** schema S in database connection D. ^On success, the
8356 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
8357 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
8358 ** If there is not already a read-transaction open on schema S when
8359 ** this function is called, one is opened automatically.
8361 ** The following must be true for this function to succeed. If any of
8362 ** the following statements are false when sqlite3_snapshot_get() is
8363 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
8367 ** <li> The database handle must be in [autocommit mode].
8369 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
8371 ** <li> There must not be a write transaction open on schema S of database
8374 ** <li> One or more transactions must have been written to the current wal
8375 ** file since it was created on disk (by any connection). This means
8376 ** that a snapshot cannot be taken on a wal mode database with no wal
8377 ** file immediately after it is first opened. At least one transaction
8378 ** must be written to it first.
8381 ** This function may also return SQLITE_NOMEM. If it is called with the
8382 ** database handle in autocommit mode but fails for some other reason,
8383 ** whether or not a read transaction is opened on schema S is undefined.
8385 ** The [sqlite3_snapshot] object returned from a successful call to
8386 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
8387 ** to avoid a memory leak.
8389 ** The [sqlite3_snapshot_get()] interface is only available when the
8390 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8392 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
8394 const char *zSchema,
8395 sqlite3_snapshot **ppSnapshot
8399 ** CAPI3REF: Start a read transaction on an historical snapshot
8402 ** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
8403 ** read transaction for schema S of
8404 ** [database connection] D such that the read transaction
8405 ** refers to historical [snapshot] P, rather than the most
8406 ** recent change to the database.
8407 ** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
8408 ** or an appropriate [error code] if it fails.
8410 ** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
8411 ** the first operation following the [BEGIN] that takes the schema S
8412 ** out of [autocommit mode].
8413 ** ^In other words, schema S must not currently be in
8414 ** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
8415 ** database connection D must be out of [autocommit mode].
8416 ** ^A [snapshot] will fail to open if it has been overwritten by a
8418 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
8419 ** database connection D does not know that the database file for
8420 ** schema S is in [WAL mode]. A database connection might not know
8421 ** that the database file is in [WAL mode] if there has been no prior
8422 ** I/O on that database connection, or if the database entered [WAL mode]
8423 ** after the most recent I/O on the database connection.)^
8424 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
8425 ** database connection in order to make it ready to use snapshots.)
8427 ** The [sqlite3_snapshot_open()] interface is only available when the
8428 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8430 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
8432 const char *zSchema,
8433 sqlite3_snapshot *pSnapshot
8437 ** CAPI3REF: Destroy a snapshot
8440 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
8441 ** The application must eventually free every [sqlite3_snapshot] object
8442 ** using this routine to avoid a memory leak.
8444 ** The [sqlite3_snapshot_free()] interface is only available when the
8445 ** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8447 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
8450 ** CAPI3REF: Compare the ages of two snapshot handles.
8453 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
8454 ** of two valid snapshot handles.
8456 ** If the two snapshot handles are not associated with the same database
8457 ** file, the result of the comparison is undefined.
8459 ** Additionally, the result of the comparison is only valid if both of the
8460 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
8461 ** last time the wal file was deleted. The wal file is deleted when the
8462 ** database is changed back to rollback mode or when the number of database
8463 ** clients drops to zero. If either snapshot handle was obtained before the
8464 ** wal file was last deleted, the value returned by this function
8467 ** Otherwise, this API returns a negative value if P1 refers to an older
8468 ** snapshot than P2, zero if the two handles refer to the same database
8469 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
8471 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
8472 sqlite3_snapshot *p1,
8473 sqlite3_snapshot *p2
8477 ** CAPI3REF: Recover snapshots from a wal file
8480 ** If all connections disconnect from a database file but do not perform
8481 ** a checkpoint, the existing wal file is opened along with the database
8482 ** file the next time the database is opened. At this point it is only
8483 ** possible to successfully call sqlite3_snapshot_open() to open the most
8484 ** recent snapshot of the database (the one at the head of the wal file),
8485 ** even though the wal file may contain other valid snapshots for which
8486 ** clients have sqlite3_snapshot handles.
8488 ** This function attempts to scan the wal file associated with database zDb
8489 ** of database handle db and make all valid snapshots available to
8490 ** sqlite3_snapshot_open(). It is an error if there is already a read
8491 ** transaction open on the database, or if the database is not a wal mode
8494 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
8496 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
8499 ** Undo the hack that converts floating point types to integer for
8500 ** builds on processors without floating point support.
8502 #ifdef SQLITE_OMIT_FLOATING_POINT
8507 } /* End of the 'extern "C"' block */
8509 #endif /* SQLITE3_H */
8511 /******** Begin file sqlite3rtree.h *********/
8515 ** The author disclaims copyright to this source code. In place of
8516 ** a legal notice, here is a blessing:
8518 ** May you do good and not evil.
8519 ** May you find forgiveness for yourself and forgive others.
8520 ** May you share freely, never taking more than you give.
8522 *************************************************************************
8525 #ifndef _SQLITE3RTREE_H_
8526 #define _SQLITE3RTREE_H_
8533 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
8534 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
8536 /* The double-precision datatype used by RTree depends on the
8537 ** SQLITE_RTREE_INT_ONLY compile-time option.
8539 #ifdef SQLITE_RTREE_INT_ONLY
8540 typedef sqlite3_int64 sqlite3_rtree_dbl;
8542 typedef double sqlite3_rtree_dbl;
8546 ** Register a geometry callback named zGeom that can be used as part of an
8547 ** R-Tree geometry query as follows:
8549 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
8551 SQLITE_API int sqlite3_rtree_geometry_callback(
8554 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
8560 ** A pointer to a structure of the following type is passed as the first
8561 ** argument to callbacks registered using rtree_geometry_callback().
8563 struct sqlite3_rtree_geometry {
8564 void *pContext; /* Copy of pContext passed to s_r_g_c() */
8565 int nParam; /* Size of array aParam[] */
8566 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
8567 void *pUser; /* Callback implementation user data */
8568 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
8572 ** Register a 2nd-generation geometry callback named zScore that can be
8573 ** used as part of an R-Tree geometry query as follows:
8575 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
8577 SQLITE_API int sqlite3_rtree_query_callback(
8579 const char *zQueryFunc,
8580 int (*xQueryFunc)(sqlite3_rtree_query_info*),
8582 void (*xDestructor)(void*)
8587 ** A pointer to a structure of the following type is passed as the
8588 ** argument to scored geometry callback registered using
8589 ** sqlite3_rtree_query_callback().
8591 ** Note that the first 5 fields of this structure are identical to
8592 ** sqlite3_rtree_geometry. This structure is a subclass of
8593 ** sqlite3_rtree_geometry.
8595 struct sqlite3_rtree_query_info {
8596 void *pContext; /* pContext from when function registered */
8597 int nParam; /* Number of function parameters */
8598 sqlite3_rtree_dbl *aParam; /* value of function parameters */
8599 void *pUser; /* callback can use this, if desired */
8600 void (*xDelUser)(void*); /* function to free pUser */
8601 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
8602 unsigned int *anQueue; /* Number of pending entries in the queue */
8603 int nCoord; /* Number of coordinates */
8604 int iLevel; /* Level of current node or entry */
8605 int mxLevel; /* The largest iLevel value in the tree */
8606 sqlite3_int64 iRowid; /* Rowid for current entry */
8607 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
8608 int eParentWithin; /* Visibility of parent node */
8609 int eWithin; /* OUT: Visiblity */
8610 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
8611 /* The following fields are only available in 3.8.11 and later */
8612 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
8616 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
8618 #define NOT_WITHIN 0 /* Object completely outside of query region */
8619 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
8620 #define FULLY_WITHIN 2 /* Object fully contained within query region */
8624 } /* end of the 'extern "C"' block */
8627 #endif /* ifndef _SQLITE3RTREE_H_ */
8629 /******** End of sqlite3rtree.h *********/
8630 /******** Begin file sqlite3session.h *********/
8632 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
8633 #define __SQLITESESSION_H_ 1
8636 ** Make sure we can call this stuff from C++.
8644 ** CAPI3REF: Session Object Handle
8646 typedef struct sqlite3_session sqlite3_session;
8649 ** CAPI3REF: Changeset Iterator Handle
8651 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
8654 ** CAPI3REF: Create A New Session Object
8656 ** Create a new session object attached to database handle db. If successful,
8657 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
8658 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
8659 ** error code (e.g. SQLITE_NOMEM) is returned.
8661 ** It is possible to create multiple session objects attached to a single
8664 ** Session objects created using this function should be deleted using the
8665 ** [sqlite3session_delete()] function before the database handle that they
8666 ** are attached to is itself closed. If the database handle is closed before
8667 ** the session object is deleted, then the results of calling any session
8668 ** module function, including [sqlite3session_delete()] on the session object
8671 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
8672 ** is not possible for an application to register a pre-update hook on a
8673 ** database handle that has one or more session objects attached. Nor is
8674 ** it possible to create a session object attached to a database handle for
8675 ** which a pre-update hook is already defined. The results of attempting
8676 ** either of these things are undefined.
8678 ** The session object will be used to create changesets for tables in
8679 ** database zDb, where zDb is either "main", or "temp", or the name of an
8680 ** attached database. It is not an error if database zDb is not attached
8681 ** to the database when the session object is created.
8683 SQLITE_API int sqlite3session_create(
8684 sqlite3 *db, /* Database handle */
8685 const char *zDb, /* Name of db (e.g. "main") */
8686 sqlite3_session **ppSession /* OUT: New session object */
8690 ** CAPI3REF: Delete A Session Object
8692 ** Delete a session object previously allocated using
8693 ** [sqlite3session_create()]. Once a session object has been deleted, the
8694 ** results of attempting to use pSession with any other session module
8695 ** function are undefined.
8697 ** Session objects must be deleted before the database handle to which they
8698 ** are attached is closed. Refer to the documentation for
8699 ** [sqlite3session_create()] for details.
8701 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
8705 ** CAPI3REF: Enable Or Disable A Session Object
8707 ** Enable or disable the recording of changes by a session object. When
8708 ** enabled, a session object records changes made to the database. When
8709 ** disabled - it does not. A newly created session object is enabled.
8710 ** Refer to the documentation for [sqlite3session_changeset()] for further
8711 ** details regarding how enabling and disabling a session object affects
8712 ** the eventual changesets.
8714 ** Passing zero to this function disables the session. Passing a value
8715 ** greater than zero enables it. Passing a value less than zero is a
8716 ** no-op, and may be used to query the current state of the session.
8718 ** The return value indicates the final state of the session object: 0 if
8719 ** the session is disabled, or 1 if it is enabled.
8721 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
8724 ** CAPI3REF: Set Or Clear the Indirect Change Flag
8726 ** Each change recorded by a session object is marked as either direct or
8727 ** indirect. A change is marked as indirect if either:
8730 ** <li> The session object "indirect" flag is set when the change is
8732 ** <li> The change is made by an SQL trigger or foreign key action
8733 ** instead of directly as a result of a users SQL statement.
8736 ** If a single row is affected by more than one operation within a session,
8737 ** then the change is considered indirect if all operations meet the criteria
8738 ** for an indirect change above, or direct otherwise.
8740 ** This function is used to set, clear or query the session object indirect
8741 ** flag. If the second argument passed to this function is zero, then the
8742 ** indirect flag is cleared. If it is greater than zero, the indirect flag
8743 ** is set. Passing a value less than zero does not modify the current value
8744 ** of the indirect flag, and may be used to query the current state of the
8745 ** indirect flag for the specified session object.
8747 ** The return value indicates the final state of the indirect flag: 0 if
8748 ** it is clear, or 1 if it is set.
8750 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
8753 ** CAPI3REF: Attach A Table To A Session Object
8755 ** If argument zTab is not NULL, then it is the name of a table to attach
8756 ** to the session object passed as the first argument. All subsequent changes
8757 ** made to the table while the session object is enabled will be recorded. See
8758 ** documentation for [sqlite3session_changeset()] for further details.
8760 ** Or, if argument zTab is NULL, then changes are recorded for all tables
8761 ** in the database. If additional tables are added to the database (by
8762 ** executing "CREATE TABLE" statements) after this call is made, changes for
8763 ** the new tables are also recorded.
8765 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
8766 ** defined as part of their CREATE TABLE statement. It does not matter if the
8767 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
8768 ** KEY may consist of a single column, or may be a composite key.
8770 ** It is not an error if the named table does not exist in the database. Nor
8771 ** is it an error if the named table does not have a PRIMARY KEY. However,
8772 ** no changes will be recorded in either of these scenarios.
8774 ** Changes are not recorded for individual rows that have NULL values stored
8775 ** in one or more of their PRIMARY KEY columns.
8777 ** SQLITE_OK is returned if the call completes without error. Or, if an error
8778 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
8780 SQLITE_API int sqlite3session_attach(
8781 sqlite3_session *pSession, /* Session object */
8782 const char *zTab /* Table name */
8786 ** CAPI3REF: Set a table filter on a Session Object.
8788 ** The second argument (xFilter) is the "filter callback". For changes to rows
8789 ** in tables that are not attached to the Session object, the filter is called
8790 ** to determine whether changes to the table's rows should be tracked or not.
8791 ** If xFilter returns 0, changes is not tracked. Note that once a table is
8792 ** attached, xFilter will not be called again.
8794 SQLITE_API void sqlite3session_table_filter(
8795 sqlite3_session *pSession, /* Session object */
8797 void *pCtx, /* Copy of third arg to _filter_table() */
8798 const char *zTab /* Table name */
8800 void *pCtx /* First argument passed to xFilter */
8804 ** CAPI3REF: Generate A Changeset From A Session Object
8806 ** Obtain a changeset containing changes to the tables attached to the
8807 ** session object passed as the first argument. If successful,
8808 ** set *ppChangeset to point to a buffer containing the changeset
8809 ** and *pnChangeset to the size of the changeset in bytes before returning
8810 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
8811 ** zero and return an SQLite error code.
8813 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
8814 ** each representing a change to a single row of an attached table. An INSERT
8815 ** change contains the values of each field of a new database row. A DELETE
8816 ** contains the original values of each field of a deleted database row. An
8817 ** UPDATE change contains the original values of each field of an updated
8818 ** database row along with the updated values for each updated non-primary-key
8819 ** column. It is not possible for an UPDATE change to represent a change that
8820 ** modifies the values of primary key columns. If such a change is made, it
8821 ** is represented in a changeset as a DELETE followed by an INSERT.
8823 ** Changes are not recorded for rows that have NULL values stored in one or
8824 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
8825 ** no corresponding change is present in the changesets returned by this
8826 ** function. If an existing row with one or more NULL values stored in
8827 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
8828 ** only an INSERT is appears in the changeset. Similarly, if an existing row
8829 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
8830 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
8831 ** DELETE change only.
8833 ** The contents of a changeset may be traversed using an iterator created
8834 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
8835 ** a database with a compatible schema using the [sqlite3changeset_apply()]
8838 ** Within a changeset generated by this function, all changes related to a
8839 ** single table are grouped together. In other words, when iterating through
8840 ** a changeset or when applying a changeset to a database, all changes related
8841 ** to a single table are processed before moving on to the next table. Tables
8842 ** are sorted in the same order in which they were attached (or auto-attached)
8843 ** to the sqlite3_session object. The order in which the changes related to
8844 ** a single table are stored is undefined.
8846 ** Following a successful call to this function, it is the responsibility of
8847 ** the caller to eventually free the buffer that *ppChangeset points to using
8848 ** [sqlite3_free()].
8850 ** <h3>Changeset Generation</h3>
8852 ** Once a table has been attached to a session object, the session object
8853 ** records the primary key values of all new rows inserted into the table.
8854 ** It also records the original primary key and other column values of any
8855 ** deleted or updated rows. For each unique primary key value, data is only
8856 ** recorded once - the first time a row with said primary key is inserted,
8857 ** updated or deleted in the lifetime of the session.
8859 ** There is one exception to the previous paragraph: when a row is inserted,
8860 ** updated or deleted, if one or more of its primary key columns contain a
8861 ** NULL value, no record of the change is made.
8863 ** The session object therefore accumulates two types of records - those
8864 ** that consist of primary key values only (created when the user inserts
8865 ** a new record) and those that consist of the primary key values and the
8866 ** original values of other table columns (created when the users deletes
8867 ** or updates a record).
8869 ** When this function is called, the requested changeset is created using
8870 ** both the accumulated records and the current contents of the database
8871 ** file. Specifically:
8874 ** <li> For each record generated by an insert, the database is queried
8875 ** for a row with a matching primary key. If one is found, an INSERT
8876 ** change is added to the changeset. If no such row is found, no change
8877 ** is added to the changeset.
8879 ** <li> For each record generated by an update or delete, the database is
8880 ** queried for a row with a matching primary key. If such a row is
8881 ** found and one or more of the non-primary key fields have been
8882 ** modified from their original values, an UPDATE change is added to
8883 ** the changeset. Or, if no such row is found in the table, a DELETE
8884 ** change is added to the changeset. If there is a row with a matching
8885 ** primary key in the database, but all fields contain their original
8886 ** values, no change is added to the changeset.
8889 ** This means, amongst other things, that if a row is inserted and then later
8890 ** deleted while a session object is active, neither the insert nor the delete
8891 ** will be present in the changeset. Or if a row is deleted and then later a
8892 ** row with the same primary key values inserted while a session object is
8893 ** active, the resulting changeset will contain an UPDATE change instead of
8894 ** a DELETE and an INSERT.
8896 ** When a session object is disabled (see the [sqlite3session_enable()] API),
8897 ** it does not accumulate records when rows are inserted, updated or deleted.
8898 ** This may appear to have some counter-intuitive effects if a single row
8899 ** is written to more than once during a session. For example, if a row
8900 ** is inserted while a session object is enabled, then later deleted while
8901 ** the same session object is disabled, no INSERT record will appear in the
8902 ** changeset, even though the delete took place while the session was disabled.
8903 ** Or, if one field of a row is updated while a session is disabled, and
8904 ** another field of the same row is updated while the session is enabled, the
8905 ** resulting changeset will contain an UPDATE change that updates both fields.
8907 SQLITE_API int sqlite3session_changeset(
8908 sqlite3_session *pSession, /* Session object */
8909 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
8910 void **ppChangeset /* OUT: Buffer containing changeset */
8914 ** CAPI3REF: Load The Difference Between Tables Into A Session
8916 ** If it is not already attached to the session object passed as the first
8917 ** argument, this function attaches table zTbl in the same manner as the
8918 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
8919 ** does not have a primary key, this function is a no-op (but does not return
8922 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
8923 ** attached to the same database handle as the session object that contains
8924 ** a table compatible with the table attached to the session by this function.
8925 ** A table is considered compatible if it:
8928 ** <li> Has the same name,
8929 ** <li> Has the same set of columns declared in the same order, and
8930 ** <li> Has the same PRIMARY KEY definition.
8933 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
8934 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
8935 ** but no changes are added to the session object. As with other session
8936 ** APIs, tables without PRIMARY KEYs are simply ignored.
8938 ** This function adds a set of changes to the session object that could be
8939 ** used to update the table in database zFrom (call this the "from-table")
8940 ** so that its content is the same as the table attached to the session
8941 ** object (call this the "to-table"). Specifically:
8944 ** <li> For each row (primary key) that exists in the to-table but not in
8945 ** the from-table, an INSERT record is added to the session object.
8947 ** <li> For each row (primary key) that exists in the to-table but not in
8948 ** the from-table, a DELETE record is added to the session object.
8950 ** <li> For each row (primary key) that exists in both tables, but features
8951 ** different non-PK values in each, an UPDATE record is added to the
8955 ** To clarify, if this function is called and then a changeset constructed
8956 ** using [sqlite3session_changeset()], then after applying that changeset to
8957 ** database zFrom the contents of the two compatible tables would be
8960 ** It an error if database zFrom does not exist or does not contain the
8961 ** required compatible table.
8963 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
8964 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
8965 ** may be set to point to a buffer containing an English language error
8966 ** message. It is the responsibility of the caller to free this buffer using
8969 SQLITE_API int sqlite3session_diff(
8970 sqlite3_session *pSession,
8971 const char *zFromDb,
8978 ** CAPI3REF: Generate A Patchset From A Session Object
8980 ** The differences between a patchset and a changeset are that:
8983 ** <li> DELETE records consist of the primary key fields only. The
8984 ** original values of other fields are omitted.
8985 ** <li> The original values of any modified fields are omitted from
8989 ** A patchset blob may be used with up to date versions of all
8990 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
8991 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
8992 ** attempting to use a patchset blob with old versions of the
8993 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
8995 ** Because the non-primary key "old.*" fields are omitted, no
8996 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
8997 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
8998 ** in the same way as for changesets.
9000 ** Changes within a patchset are ordered in the same way as for changesets
9001 ** generated by the sqlite3session_changeset() function (i.e. all changes for
9002 ** a single table are grouped together, tables appear in the order in which
9003 ** they were attached to the session object).
9005 SQLITE_API int sqlite3session_patchset(
9006 sqlite3_session *pSession, /* Session object */
9007 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */
9008 void **ppPatchset /* OUT: Buffer containing changeset */
9012 ** CAPI3REF: Test if a changeset has recorded any changes.
9014 ** Return non-zero if no changes to attached tables have been recorded by
9015 ** the session object passed as the first argument. Otherwise, if one or
9016 ** more changes have been recorded, return zero.
9018 ** Even if this function returns zero, it is possible that calling
9019 ** [sqlite3session_changeset()] on the session handle may still return a
9020 ** changeset that contains no changes. This can happen when a row in
9021 ** an attached table is modified and then later on the original values
9022 ** are restored. However, if this function returns non-zero, then it is
9023 ** guaranteed that a call to sqlite3session_changeset() will return a
9024 ** changeset containing zero changes.
9026 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9029 ** CAPI3REF: Create An Iterator To Traverse A Changeset
9031 ** Create an iterator used to iterate through the contents of a changeset.
9032 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9033 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9034 ** SQLite error code is returned.
9036 ** The following functions can be used to advance and query a changeset
9037 ** iterator created by this function:
9040 ** <li> [sqlite3changeset_next()]
9041 ** <li> [sqlite3changeset_op()]
9042 ** <li> [sqlite3changeset_new()]
9043 ** <li> [sqlite3changeset_old()]
9046 ** It is the responsibility of the caller to eventually destroy the iterator
9047 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9048 ** changeset (pChangeset) must remain valid until after the iterator is
9051 ** Assuming the changeset blob was created by one of the
9052 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9053 ** [sqlite3changeset_invert()] functions, all changes within the changeset
9054 ** that apply to a single table are grouped together. This means that when
9055 ** an application iterates through a changeset using an iterator created by
9056 ** this function, all changes that relate to a single table are visited
9057 ** consecutively. There is no chance that the iterator will visit a change
9058 ** the applies to table X, then one for table Y, and then later on visit
9059 ** another change for table X.
9061 SQLITE_API int sqlite3changeset_start(
9062 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9063 int nChangeset, /* Size of changeset blob in bytes */
9064 void *pChangeset /* Pointer to blob containing changeset */
9069 ** CAPI3REF: Advance A Changeset Iterator
9071 ** This function may only be used with iterators created by function
9072 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
9073 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9074 ** is returned and the call has no effect.
9076 ** Immediately after an iterator is created by sqlite3changeset_start(), it
9077 ** does not point to any change in the changeset. Assuming the changeset
9078 ** is not empty, the first call to this function advances the iterator to
9079 ** point to the first change in the changeset. Each subsequent call advances
9080 ** the iterator to point to the next change in the changeset (if any). If
9081 ** no error occurs and the iterator points to a valid change after a call
9082 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
9083 ** Otherwise, if all changes in the changeset have already been visited,
9084 ** SQLITE_DONE is returned.
9086 ** If an error occurs, an SQLite error code is returned. Possible error
9087 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
9090 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
9093 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
9095 ** The pIter argument passed to this function may either be an iterator
9096 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9097 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9098 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
9099 ** is not the case, this function returns [SQLITE_MISUSE].
9101 ** If argument pzTab is not NULL, then *pzTab is set to point to a
9102 ** nul-terminated utf-8 encoded string containing the name of the table
9103 ** affected by the current change. The buffer remains valid until either
9104 ** sqlite3changeset_next() is called on the iterator or until the
9105 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
9106 ** set to the number of columns in the table affected by the change. If
9107 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
9108 ** is an indirect change, or false (0) otherwise. See the documentation for
9109 ** [sqlite3session_indirect()] for a description of direct and indirect
9110 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of
9111 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
9112 ** type of change that the iterator currently points to.
9114 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
9115 ** SQLite error code is returned. The values of the output variables may not
9116 ** be trusted in this case.
9118 SQLITE_API int sqlite3changeset_op(
9119 sqlite3_changeset_iter *pIter, /* Iterator object */
9120 const char **pzTab, /* OUT: Pointer to table name */
9121 int *pnCol, /* OUT: Number of columns in table */
9122 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
9123 int *pbIndirect /* OUT: True for an 'indirect' change */
9127 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
9129 ** For each modified table, a changeset includes the following:
9132 ** <li> The number of columns in the table, and
9133 ** <li> Which of those columns make up the tables PRIMARY KEY.
9136 ** This function is used to find which columns comprise the PRIMARY KEY of
9137 ** the table modified by the change that iterator pIter currently points to.
9138 ** If successful, *pabPK is set to point to an array of nCol entries, where
9139 ** nCol is the number of columns in the table. Elements of *pabPK are set to
9140 ** 0x01 if the corresponding column is part of the tables primary key, or
9141 ** 0x00 if it is not.
9143 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
9146 ** If this function is called when the iterator does not point to a valid
9147 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
9148 ** SQLITE_OK is returned and the output variables populated as described
9151 SQLITE_API int sqlite3changeset_pk(
9152 sqlite3_changeset_iter *pIter, /* Iterator object */
9153 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
9154 int *pnCol /* OUT: Number of entries in output array */
9158 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
9160 ** The pIter argument passed to this function may either be an iterator
9161 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9162 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9163 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9164 ** Furthermore, it may only be called if the type of change that the iterator
9165 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
9166 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9168 ** Argument iVal must be greater than or equal to 0, and less than the number
9169 ** of columns in the table affected by the current change. Otherwise,
9170 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9172 ** If successful, this function sets *ppValue to point to a protected
9173 ** sqlite3_value object containing the iVal'th value from the vector of
9174 ** original row values stored as part of the UPDATE or DELETE change and
9175 ** returns SQLITE_OK. The name of the function comes from the fact that this
9176 ** is similar to the "old.*" columns available to update or delete triggers.
9178 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9179 ** is returned and *ppValue is set to NULL.
9181 SQLITE_API int sqlite3changeset_old(
9182 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9183 int iVal, /* Column number */
9184 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
9188 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
9190 ** The pIter argument passed to this function may either be an iterator
9191 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9192 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
9193 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9194 ** Furthermore, it may only be called if the type of change that the iterator
9195 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
9196 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9198 ** Argument iVal must be greater than or equal to 0, and less than the number
9199 ** of columns in the table affected by the current change. Otherwise,
9200 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9202 ** If successful, this function sets *ppValue to point to a protected
9203 ** sqlite3_value object containing the iVal'th value from the vector of
9204 ** new row values stored as part of the UPDATE or INSERT change and
9205 ** returns SQLITE_OK. If the change is an UPDATE and does not include
9206 ** a new value for the requested column, *ppValue is set to NULL and
9207 ** SQLITE_OK returned. The name of the function comes from the fact that
9208 ** this is similar to the "new.*" columns available to update or delete
9211 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9212 ** is returned and *ppValue is set to NULL.
9214 SQLITE_API int sqlite3changeset_new(
9215 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9216 int iVal, /* Column number */
9217 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
9221 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
9223 ** This function should only be used with iterator objects passed to a
9224 ** conflict-handler callback by [sqlite3changeset_apply()] with either
9225 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
9226 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
9229 ** Argument iVal must be greater than or equal to 0, and less than the number
9230 ** of columns in the table affected by the current change. Otherwise,
9231 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9233 ** If successful, this function sets *ppValue to point to a protected
9234 ** sqlite3_value object containing the iVal'th value from the
9235 ** "conflicting row" associated with the current conflict-handler callback
9236 ** and returns SQLITE_OK.
9238 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
9239 ** is returned and *ppValue is set to NULL.
9241 SQLITE_API int sqlite3changeset_conflict(
9242 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9243 int iVal, /* Column number */
9244 sqlite3_value **ppValue /* OUT: Value from conflicting row */
9248 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
9250 ** This function may only be called with an iterator passed to an
9251 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
9252 ** it sets the output variable to the total number of known foreign key
9253 ** violations in the destination database and returns SQLITE_OK.
9255 ** In all other cases this function returns SQLITE_MISUSE.
9257 SQLITE_API int sqlite3changeset_fk_conflicts(
9258 sqlite3_changeset_iter *pIter, /* Changeset iterator */
9259 int *pnOut /* OUT: Number of FK violations */
9264 ** CAPI3REF: Finalize A Changeset Iterator
9266 ** This function is used to finalize an iterator allocated with
9267 ** [sqlite3changeset_start()].
9269 ** This function should only be called on iterators created using the
9270 ** [sqlite3changeset_start()] function. If an application calls this
9271 ** function with an iterator passed to a conflict-handler by
9272 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
9273 ** call has no effect.
9275 ** If an error was encountered within a call to an sqlite3changeset_xxx()
9276 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
9277 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
9278 ** to that error is returned by this function. Otherwise, SQLITE_OK is
9279 ** returned. This is to allow the following pattern (pseudo-code):
9281 ** sqlite3changeset_start();
9282 ** while( SQLITE_ROW==sqlite3changeset_next() ){
9283 ** // Do something with change.
9285 ** rc = sqlite3changeset_finalize();
9286 ** if( rc!=SQLITE_OK ){
9287 ** // An error has occurred
9290 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
9293 ** CAPI3REF: Invert A Changeset
9295 ** This function is used to "invert" a changeset object. Applying an inverted
9296 ** changeset to a database reverses the effects of applying the uninverted
9297 ** changeset. Specifically:
9300 ** <li> Each DELETE change is changed to an INSERT, and
9301 ** <li> Each INSERT change is changed to a DELETE, and
9302 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
9305 ** This function does not change the order in which changes appear within
9306 ** the changeset. It merely reverses the sense of each individual change.
9308 ** If successful, a pointer to a buffer containing the inverted changeset
9309 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
9310 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
9311 ** zeroed and an SQLite error code returned.
9313 ** It is the responsibility of the caller to eventually call sqlite3_free()
9314 ** on the *ppOut pointer to free the buffer allocation following a successful
9315 ** call to this function.
9317 ** WARNING/TODO: This function currently assumes that the input is a valid
9318 ** changeset. If it is not, the results are undefined.
9320 SQLITE_API int sqlite3changeset_invert(
9321 int nIn, const void *pIn, /* Input changeset */
9322 int *pnOut, void **ppOut /* OUT: Inverse of input */
9326 ** CAPI3REF: Concatenate Two Changeset Objects
9328 ** This function is used to concatenate two changesets, A and B, into a
9329 ** single changeset. The result is a changeset equivalent to applying
9330 ** changeset A followed by changeset B.
9332 ** This function combines the two input changesets using an
9333 ** sqlite3_changegroup object. Calling it produces similar results as the
9334 ** following code fragment:
9336 ** sqlite3_changegroup *pGrp;
9337 ** rc = sqlite3_changegroup_new(&pGrp);
9338 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
9339 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
9340 ** if( rc==SQLITE_OK ){
9341 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
9347 ** Refer to the sqlite3_changegroup documentation below for details.
9349 SQLITE_API int sqlite3changeset_concat(
9350 int nA, /* Number of bytes in buffer pA */
9351 void *pA, /* Pointer to buffer containing changeset A */
9352 int nB, /* Number of bytes in buffer pB */
9353 void *pB, /* Pointer to buffer containing changeset B */
9354 int *pnOut, /* OUT: Number of bytes in output changeset */
9355 void **ppOut /* OUT: Buffer containing output changeset */
9360 ** CAPI3REF: Changegroup Handle
9362 typedef struct sqlite3_changegroup sqlite3_changegroup;
9365 ** CAPI3REF: Create A New Changegroup Object
9367 ** An sqlite3_changegroup object is used to combine two or more changesets
9368 ** (or patchsets) into a single changeset (or patchset). A single changegroup
9369 ** object may combine changesets or patchsets, but not both. The output is
9370 ** always in the same format as the input.
9372 ** If successful, this function returns SQLITE_OK and populates (*pp) with
9373 ** a pointer to a new sqlite3_changegroup object before returning. The caller
9374 ** should eventually free the returned object using a call to
9375 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
9376 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
9378 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
9381 ** <li> It is created using a call to sqlite3changegroup_new().
9383 ** <li> Zero or more changesets (or patchsets) are added to the object
9384 ** by calling sqlite3changegroup_add().
9386 ** <li> The result of combining all input changesets together is obtained
9387 ** by the application via a call to sqlite3changegroup_output().
9389 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
9392 ** Any number of calls to add() and output() may be made between the calls to
9393 ** new() and delete(), and in any order.
9395 ** As well as the regular sqlite3changegroup_add() and
9396 ** sqlite3changegroup_output() functions, also available are the streaming
9397 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
9399 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
9402 ** CAPI3REF: Add A Changeset To A Changegroup
9404 ** Add all changes within the changeset (or patchset) in buffer pData (size
9405 ** nData bytes) to the changegroup.
9407 ** If the buffer contains a patchset, then all prior calls to this function
9408 ** on the same changegroup object must also have specified patchsets. Or, if
9409 ** the buffer contains a changeset, so must have the earlier calls to this
9410 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
9411 ** to the changegroup.
9413 ** Rows within the changeset and changegroup are identified by the values in
9414 ** their PRIMARY KEY columns. A change in the changeset is considered to
9415 ** apply to the same row as a change already present in the changegroup if
9416 ** the two rows have the same primary key.
9418 ** Changes to rows that do not already appear in the changegroup are
9419 ** simply copied into it. Or, if both the new changeset and the changegroup
9420 ** contain changes that apply to a single row, the final contents of the
9421 ** changegroup depends on the type of each change, as follows:
9423 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
9424 ** <tr><th style="white-space:pre">Existing Change </th>
9425 ** <th style="white-space:pre">New Change </th>
9426 ** <th>Output Change
9427 ** <tr><td>INSERT <td>INSERT <td>
9428 ** The new change is ignored. This case does not occur if the new
9429 ** changeset was recorded immediately after the changesets already
9430 ** added to the changegroup.
9431 ** <tr><td>INSERT <td>UPDATE <td>
9432 ** The INSERT change remains in the changegroup. The values in the
9433 ** INSERT change are modified as if the row was inserted by the
9434 ** existing change and then updated according to the new change.
9435 ** <tr><td>INSERT <td>DELETE <td>
9436 ** The existing INSERT is removed from the changegroup. The DELETE is
9438 ** <tr><td>UPDATE <td>INSERT <td>
9439 ** The new change is ignored. This case does not occur if the new
9440 ** changeset was recorded immediately after the changesets already
9441 ** added to the changegroup.
9442 ** <tr><td>UPDATE <td>UPDATE <td>
9443 ** The existing UPDATE remains within the changegroup. It is amended
9444 ** so that the accompanying values are as if the row was updated once
9445 ** by the existing change and then again by the new change.
9446 ** <tr><td>UPDATE <td>DELETE <td>
9447 ** The existing UPDATE is replaced by the new DELETE within the
9449 ** <tr><td>DELETE <td>INSERT <td>
9450 ** If one or more of the column values in the row inserted by the
9451 ** new change differ from those in the row deleted by the existing
9452 ** change, the existing DELETE is replaced by an UPDATE within the
9453 ** changegroup. Otherwise, if the inserted row is exactly the same
9454 ** as the deleted row, the existing DELETE is simply discarded.
9455 ** <tr><td>DELETE <td>UPDATE <td>
9456 ** The new change is ignored. This case does not occur if the new
9457 ** changeset was recorded immediately after the changesets already
9458 ** added to the changegroup.
9459 ** <tr><td>DELETE <td>DELETE <td>
9460 ** The new change is ignored. This case does not occur if the new
9461 ** changeset was recorded immediately after the changesets already
9462 ** added to the changegroup.
9465 ** If the new changeset contains changes to a table that is already present
9466 ** in the changegroup, then the number of columns and the position of the
9467 ** primary key columns for the table must be consistent. If this is not the
9468 ** case, this function fails with SQLITE_SCHEMA. If the input changeset
9469 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
9470 ** returned. Or, if an out-of-memory condition occurs during processing, this
9471 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the
9472 ** final contents of the changegroup is undefined.
9474 ** If no error occurs, SQLITE_OK is returned.
9476 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
9479 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
9481 ** Obtain a buffer containing a changeset (or patchset) representing the
9482 ** current contents of the changegroup. If the inputs to the changegroup
9483 ** were themselves changesets, the output is a changeset. Or, if the
9484 ** inputs were patchsets, the output is also a patchset.
9486 ** As with the output of the sqlite3session_changeset() and
9487 ** sqlite3session_patchset() functions, all changes related to a single
9488 ** table are grouped together in the output of this function. Tables appear
9489 ** in the same order as for the very first changeset added to the changegroup.
9490 ** If the second or subsequent changesets added to the changegroup contain
9491 ** changes for tables that do not appear in the first changeset, they are
9492 ** appended onto the end of the output changeset, again in the order in
9493 ** which they are first encountered.
9495 ** If an error occurs, an SQLite error code is returned and the output
9496 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
9497 ** is returned and the output variables are set to the size of and a
9498 ** pointer to the output buffer, respectively. In this case it is the
9499 ** responsibility of the caller to eventually free the buffer using a
9500 ** call to sqlite3_free().
9502 SQLITE_API int sqlite3changegroup_output(
9503 sqlite3_changegroup*,
9504 int *pnData, /* OUT: Size of output buffer in bytes */
9505 void **ppData /* OUT: Pointer to output buffer */
9509 ** CAPI3REF: Delete A Changegroup Object
9511 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
9514 ** CAPI3REF: Apply A Changeset To A Database
9516 ** Apply a changeset to a database. This function attempts to update the
9517 ** "main" database attached to handle db with the changes found in the
9518 ** changeset passed via the second and third arguments.
9520 ** The fourth argument (xFilter) passed to this function is the "filter
9521 ** callback". If it is not NULL, then for each table affected by at least one
9522 ** change in the changeset, the filter callback is invoked with
9523 ** the table name as the second argument, and a copy of the context pointer
9524 ** passed as the sixth argument to this function as the first. If the "filter
9525 ** callback" returns zero, then no attempt is made to apply any changes to
9526 ** the table. Otherwise, if the return value is non-zero or the xFilter
9527 ** argument to this function is NULL, all changes related to the table are
9530 ** For each table that is not excluded by the filter callback, this function
9531 ** tests that the target database contains a compatible table. A table is
9532 ** considered compatible if all of the following are true:
9535 ** <li> The table has the same name as the name recorded in the
9537 ** <li> The table has at least as many columns as recorded in the
9539 ** <li> The table has primary key columns in the same position as
9540 ** recorded in the changeset.
9543 ** If there is no compatible table, it is not an error, but none of the
9544 ** changes associated with the table are applied. A warning message is issued
9545 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
9546 ** one such warning is issued for each table in the changeset.
9548 ** For each change for which there is a compatible table, an attempt is made
9549 ** to modify the table contents according to the UPDATE, INSERT or DELETE
9550 ** change. If a change cannot be applied cleanly, the conflict handler
9551 ** function passed as the fifth argument to sqlite3changeset_apply() may be
9552 ** invoked. A description of exactly when the conflict handler is invoked for
9553 ** each type of change is below.
9555 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
9556 ** of passing anything other than a valid function pointer as the xConflict
9557 ** argument are undefined.
9559 ** Each time the conflict handler function is invoked, it must return one
9560 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
9561 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
9562 ** if the second argument passed to the conflict handler is either
9563 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
9564 ** returns an illegal value, any changes already made are rolled back and
9565 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
9566 ** actions are taken by sqlite3changeset_apply() depending on the value
9567 ** returned by each invocation of the conflict-handler function. Refer to
9568 ** the documentation for the three
9569 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
9572 ** <dt>DELETE Changes<dd>
9573 ** For each DELETE change, this function checks if the target database
9574 ** contains a row with the same primary key value (or values) as the
9575 ** original row values stored in the changeset. If it does, and the values
9576 ** stored in all non-primary key columns also match the values stored in
9577 ** the changeset the row is deleted from the target database.
9579 ** If a row with matching primary key values is found, but one or more of
9580 ** the non-primary key fields contains a value different from the original
9581 ** row value stored in the changeset, the conflict-handler function is
9582 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
9583 ** database table has more columns than are recorded in the changeset,
9584 ** only the values of those non-primary key fields are compared against
9585 ** the current database contents - any trailing database table columns
9588 ** If no row with matching primary key values is found in the database,
9589 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9590 ** passed as the second argument.
9592 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
9593 ** (which can only happen if a foreign key constraint is violated), the
9594 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
9595 ** passed as the second argument. This includes the case where the DELETE
9596 ** operation is attempted because an earlier call to the conflict handler
9597 ** function returned [SQLITE_CHANGESET_REPLACE].
9599 ** <dt>INSERT Changes<dd>
9600 ** For each INSERT change, an attempt is made to insert the new row into
9601 ** the database. If the changeset row contains fewer fields than the
9602 ** database table, the trailing fields are populated with their default
9605 ** If the attempt to insert the row fails because the database already
9606 ** contains a row with the same primary key values, the conflict handler
9607 ** function is invoked with the second argument set to
9608 ** [SQLITE_CHANGESET_CONFLICT].
9610 ** If the attempt to insert the row fails because of some other constraint
9611 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
9612 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
9613 ** This includes the case where the INSERT operation is re-attempted because
9614 ** an earlier call to the conflict handler function returned
9615 ** [SQLITE_CHANGESET_REPLACE].
9617 ** <dt>UPDATE Changes<dd>
9618 ** For each UPDATE change, this function checks if the target database
9619 ** contains a row with the same primary key value (or values) as the
9620 ** original row values stored in the changeset. If it does, and the values
9621 ** stored in all modified non-primary key columns also match the values
9622 ** stored in the changeset the row is updated within the target database.
9624 ** If a row with matching primary key values is found, but one or more of
9625 ** the modified non-primary key fields contains a value different from an
9626 ** original row value stored in the changeset, the conflict-handler function
9627 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
9628 ** UPDATE changes only contain values for non-primary key fields that are
9629 ** to be modified, only those fields need to match the original values to
9630 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
9632 ** If no row with matching primary key values is found in the database,
9633 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9634 ** passed as the second argument.
9636 ** If the UPDATE operation is attempted, but SQLite returns
9637 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
9638 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
9639 ** This includes the case where the UPDATE operation is attempted after
9640 ** an earlier call to the conflict handler function returned
9641 ** [SQLITE_CHANGESET_REPLACE].
9644 ** It is safe to execute SQL statements, including those that write to the
9645 ** table that the callback related to, from within the xConflict callback.
9646 ** This can be used to further customize the applications conflict
9647 ** resolution strategy.
9649 ** All changes made by this function are enclosed in a savepoint transaction.
9650 ** If any other error (aside from a constraint failure when attempting to
9651 ** write to the target database) occurs, then the savepoint transaction is
9652 ** rolled back, restoring the target database to its original state, and an
9653 ** SQLite error code returned.
9655 SQLITE_API int sqlite3changeset_apply(
9656 sqlite3 *db, /* Apply change to "main" db of this handle */
9657 int nChangeset, /* Size of changeset in bytes */
9658 void *pChangeset, /* Changeset blob */
9660 void *pCtx, /* Copy of sixth arg to _apply() */
9661 const char *zTab /* Table name */
9664 void *pCtx, /* Copy of sixth arg to _apply() */
9665 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9666 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9668 void *pCtx /* First argument passed to xConflict */
9672 ** CAPI3REF: Constants Passed To The Conflict Handler
9674 ** Values that may be passed as the second argument to a conflict-handler.
9677 ** <dt>SQLITE_CHANGESET_DATA<dd>
9678 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
9679 ** when processing a DELETE or UPDATE change if a row with the required
9680 ** PRIMARY KEY fields is present in the database, but one or more other
9681 ** (non primary-key) fields modified by the update do not contain the
9682 ** expected "before" values.
9684 ** The conflicting row, in this case, is the database row with the matching
9687 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
9688 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
9689 ** argument when processing a DELETE or UPDATE change if a row with the
9690 ** required PRIMARY KEY fields is not present in the database.
9692 ** There is no conflicting row in this case. The results of invoking the
9693 ** sqlite3changeset_conflict() API are undefined.
9695 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
9696 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
9697 ** handler while processing an INSERT change if the operation would result
9698 ** in duplicate primary key values.
9700 ** The conflicting row in this case is the database row with the matching
9703 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
9704 ** If foreign key handling is enabled, and applying a changeset leaves the
9705 ** database in a state containing foreign key violations, the conflict
9706 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
9707 ** exactly once before the changeset is committed. If the conflict handler
9708 ** returns CHANGESET_OMIT, the changes, including those that caused the
9709 ** foreign key constraint violation, are committed. Or, if it returns
9710 ** CHANGESET_ABORT, the changeset is rolled back.
9712 ** No current or conflicting row information is provided. The only function
9713 ** it is possible to call on the supplied sqlite3_changeset_iter handle
9714 ** is sqlite3changeset_fk_conflicts().
9716 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
9717 ** If any other constraint violation occurs while applying a change (i.e.
9718 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
9719 ** invoked with CHANGESET_CONSTRAINT as the second argument.
9721 ** There is no conflicting row in this case. The results of invoking the
9722 ** sqlite3changeset_conflict() API are undefined.
9726 #define SQLITE_CHANGESET_DATA 1
9727 #define SQLITE_CHANGESET_NOTFOUND 2
9728 #define SQLITE_CHANGESET_CONFLICT 3
9729 #define SQLITE_CHANGESET_CONSTRAINT 4
9730 #define SQLITE_CHANGESET_FOREIGN_KEY 5
9733 ** CAPI3REF: Constants Returned By The Conflict Handler
9735 ** A conflict handler callback must return one of the following three values.
9738 ** <dt>SQLITE_CHANGESET_OMIT<dd>
9739 ** If a conflict handler returns this value no special action is taken. The
9740 ** change that caused the conflict is not applied. The session module
9741 ** continues to the next change in the changeset.
9743 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
9744 ** This value may only be returned if the second argument to the conflict
9745 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
9746 ** is not the case, any changes applied so far are rolled back and the
9747 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
9749 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
9750 ** handler, then the conflicting row is either updated or deleted, depending
9751 ** on the type of change.
9753 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
9754 ** handler, then the conflicting row is removed from the database and a
9755 ** second attempt to apply the change is made. If this second attempt fails,
9756 ** the original row is restored to the database before continuing.
9758 ** <dt>SQLITE_CHANGESET_ABORT<dd>
9759 ** If this value is returned, any changes applied so far are rolled back
9760 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
9763 #define SQLITE_CHANGESET_OMIT 0
9764 #define SQLITE_CHANGESET_REPLACE 1
9765 #define SQLITE_CHANGESET_ABORT 2
9768 ** CAPI3REF: Streaming Versions of API functions.
9770 ** The six streaming API xxx_strm() functions serve similar purposes to the
9771 ** corresponding non-streaming API functions:
9773 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
9774 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
9775 ** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply]
9776 ** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat]
9777 ** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert]
9778 ** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start]
9779 ** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset]
9780 ** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset]
9783 ** Non-streaming functions that accept changesets (or patchsets) as input
9784 ** require that the entire changeset be stored in a single buffer in memory.
9785 ** Similarly, those that return a changeset or patchset do so by returning
9786 ** a pointer to a single large buffer allocated using sqlite3_malloc().
9787 ** Normally this is convenient. However, if an application running in a
9788 ** low-memory environment is required to handle very large changesets, the
9789 ** large contiguous memory allocations required can become onerous.
9791 ** In order to avoid this problem, instead of a single large buffer, input
9792 ** is passed to a streaming API functions by way of a callback function that
9793 ** the sessions module invokes to incrementally request input data as it is
9794 ** required. In all cases, a pair of API function parameters such as
9797 ** int nChangeset,
9798 ** void *pChangeset,
9804 ** int (*xInput)(void *pIn, void *pData, int *pnData),
9805 ** void *pIn,
9808 ** Each time the xInput callback is invoked by the sessions module, the first
9809 ** argument passed is a copy of the supplied pIn context pointer. The second
9810 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
9811 ** error occurs the xInput method should copy up to (*pnData) bytes of data
9812 ** into the buffer and set (*pnData) to the actual number of bytes copied
9813 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
9814 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
9815 ** error code should be returned. In all cases, if an xInput callback returns
9816 ** an error, all processing is abandoned and the streaming API function
9817 ** returns a copy of the error code to the caller.
9819 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
9820 ** invoked by the sessions module at any point during the lifetime of the
9821 ** iterator. If such an xInput callback returns an error, the iterator enters
9822 ** an error state, whereby all subsequent calls to iterator functions
9823 ** immediately fail with the same error code as returned by xInput.
9825 ** Similarly, streaming API functions that return changesets (or patchsets)
9826 ** return them in chunks by way of a callback function instead of via a
9827 ** pointer to a single large buffer. In this case, a pair of parameters such
9831 ** int *pnChangeset,
9832 ** void **ppChangeset,
9838 ** int (*xOutput)(void *pOut, const void *pData, int nData),
9839 ** void *pOut
9842 ** The xOutput callback is invoked zero or more times to return data to
9843 ** the application. The first parameter passed to each call is a copy of the
9844 ** pOut pointer supplied by the application. The second parameter, pData,
9845 ** points to a buffer nData bytes in size containing the chunk of output
9846 ** data being returned. If the xOutput callback successfully processes the
9847 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
9848 ** it should return some other SQLite error code. In this case processing
9849 ** is immediately abandoned and the streaming API function returns a copy
9850 ** of the xOutput error code to the application.
9852 ** The sessions module never invokes an xOutput callback with the third
9853 ** parameter set to a value less than or equal to zero. Other than this,
9854 ** no guarantees are made as to the size of the chunks of data returned.
9856 SQLITE_API int sqlite3changeset_apply_strm(
9857 sqlite3 *db, /* Apply change to "main" db of this handle */
9858 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
9859 void *pIn, /* First arg for xInput */
9861 void *pCtx, /* Copy of sixth arg to _apply() */
9862 const char *zTab /* Table name */
9865 void *pCtx, /* Copy of sixth arg to _apply() */
9866 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9867 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9869 void *pCtx /* First argument passed to xConflict */
9871 SQLITE_API int sqlite3changeset_concat_strm(
9872 int (*xInputA)(void *pIn, void *pData, int *pnData),
9874 int (*xInputB)(void *pIn, void *pData, int *pnData),
9876 int (*xOutput)(void *pOut, const void *pData, int nData),
9879 SQLITE_API int sqlite3changeset_invert_strm(
9880 int (*xInput)(void *pIn, void *pData, int *pnData),
9882 int (*xOutput)(void *pOut, const void *pData, int nData),
9885 SQLITE_API int sqlite3changeset_start_strm(
9886 sqlite3_changeset_iter **pp,
9887 int (*xInput)(void *pIn, void *pData, int *pnData),
9890 SQLITE_API int sqlite3session_changeset_strm(
9891 sqlite3_session *pSession,
9892 int (*xOutput)(void *pOut, const void *pData, int nData),
9895 SQLITE_API int sqlite3session_patchset_strm(
9896 sqlite3_session *pSession,
9897 int (*xOutput)(void *pOut, const void *pData, int nData),
9900 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
9901 int (*xInput)(void *pIn, void *pData, int *pnData),
9904 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
9905 int (*xOutput)(void *pOut, const void *pData, int nData),
9911 ** Make sure we can call this stuff from C++.
9917 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
9919 /******** End of sqlite3session.h *********/
9920 /******** Begin file fts5.h *********/
9924 ** The author disclaims copyright to this source code. In place of
9925 ** a legal notice, here is a blessing:
9927 ** May you do good and not evil.
9928 ** May you find forgiveness for yourself and forgive others.
9929 ** May you share freely, never taking more than you give.
9931 ******************************************************************************
9933 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
9934 ** FTS5 may be extended with:
9936 ** * custom tokenizers, and
9937 ** * custom auxiliary functions.
9949 /*************************************************************************
9950 ** CUSTOM AUXILIARY FUNCTIONS
9952 ** Virtual table implementations may overload SQL functions by implementing
9953 ** the sqlite3_module.xFindFunction() method.
9956 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
9957 typedef struct Fts5Context Fts5Context;
9958 typedef struct Fts5PhraseIter Fts5PhraseIter;
9960 typedef void (*fts5_extension_function)(
9961 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
9962 Fts5Context *pFts, /* First arg to pass to pApi functions */
9963 sqlite3_context *pCtx, /* Context for returning result/error */
9964 int nVal, /* Number of values in apVal[] array */
9965 sqlite3_value **apVal /* Array of trailing arguments */
9968 struct Fts5PhraseIter {
9969 const unsigned char *a;
9970 const unsigned char *b;
9974 ** EXTENSION API FUNCTIONS
9977 ** Return a copy of the context pointer the extension function was
9980 ** xColumnTotalSize(pFts, iCol, pnToken):
9981 ** If parameter iCol is less than zero, set output variable *pnToken
9982 ** to the total number of tokens in the FTS5 table. Or, if iCol is
9983 ** non-negative but less than the number of columns in the table, return
9984 ** the total number of tokens in column iCol, considering all rows in
9987 ** If parameter iCol is greater than or equal to the number of columns
9988 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
9989 ** an OOM condition or IO error), an appropriate SQLite error code is
9992 ** xColumnCount(pFts):
9993 ** Return the number of columns in the table.
9995 ** xColumnSize(pFts, iCol, pnToken):
9996 ** If parameter iCol is less than zero, set output variable *pnToken
9997 ** to the total number of tokens in the current row. Or, if iCol is
9998 ** non-negative but less than the number of columns in the table, set
9999 ** *pnToken to the number of tokens in column iCol of the current row.
10001 ** If parameter iCol is greater than or equal to the number of columns
10002 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
10003 ** an OOM condition or IO error), an appropriate SQLite error code is
10006 ** This function may be quite inefficient if used with an FTS5 table
10007 ** created with the "columnsize=0" option.
10010 ** This function attempts to retrieve the text of column iCol of the
10011 ** current document. If successful, (*pz) is set to point to a buffer
10012 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
10013 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
10014 ** if an error occurs, an SQLite error code is returned and the final values
10015 ** of (*pz) and (*pn) are undefined.
10018 ** Returns the number of phrases in the current query expression.
10021 ** Returns the number of tokens in phrase iPhrase of the query. Phrases
10022 ** are numbered starting from zero.
10025 ** Set *pnInst to the total number of occurrences of all phrases within
10026 ** the query within the current row. Return SQLITE_OK if successful, or
10027 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
10029 ** This API can be quite slow if used with an FTS5 table created with the
10030 ** "detail=none" or "detail=column" option. If the FTS5 table is created
10031 ** with either "detail=none" or "detail=column" and "content=" option
10032 ** (i.e. if it is a contentless table), then this API always returns 0.
10035 ** Query for the details of phrase match iIdx within the current row.
10036 ** Phrase matches are numbered starting from zero, so the iIdx argument
10037 ** should be greater than or equal to zero and smaller than the value
10038 ** output by xInstCount().
10040 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol
10041 ** to the column in which it occurs and *piOff the token offset of the
10042 ** first token of the phrase. The exception is if the table was created
10043 ** with the offsets=0 option specified. In this case *piOff is always
10046 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
10047 ** if an error occurs.
10049 ** This API can be quite slow if used with an FTS5 table created with the
10050 ** "detail=none" or "detail=column" option.
10053 ** Returns the rowid of the current row.
10056 ** Tokenize text using the tokenizer belonging to the FTS5 table.
10058 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
10059 ** This API function is used to query the FTS table for phrase iPhrase
10060 ** of the current query. Specifically, a query equivalent to:
10062 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
10064 ** with $p set to a phrase equivalent to the phrase iPhrase of the
10065 ** current query is executed. Any column filter that applies to
10066 ** phrase iPhrase of the current query is included in $p. For each
10067 ** row visited, the callback function passed as the fourth argument
10068 ** is invoked. The context and API objects passed to the callback
10069 ** function may be used to access the properties of each matched row.
10070 ** Invoking Api.xUserData() returns a copy of the pointer passed as
10071 ** the third argument to pUserData.
10073 ** If the callback function returns any value other than SQLITE_OK, the
10074 ** query is abandoned and the xQueryPhrase function returns immediately.
10075 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
10076 ** Otherwise, the error code is propagated upwards.
10078 ** If the query runs to completion without incident, SQLITE_OK is returned.
10079 ** Or, if some error occurs before the query completes or is aborted by
10080 ** the callback, an SQLite error code is returned.
10083 ** xSetAuxdata(pFts5, pAux, xDelete)
10085 ** Save the pointer passed as the second argument as the extension functions
10086 ** "auxiliary data". The pointer may then be retrieved by the current or any
10087 ** future invocation of the same fts5 extension function made as part of
10088 ** of the same MATCH query using the xGetAuxdata() API.
10090 ** Each extension function is allocated a single auxiliary data slot for
10091 ** each FTS query (MATCH expression). If the extension function is invoked
10092 ** more than once for a single FTS query, then all invocations share a
10093 ** single auxiliary data context.
10095 ** If there is already an auxiliary data pointer when this function is
10096 ** invoked, then it is replaced by the new pointer. If an xDelete callback
10097 ** was specified along with the original pointer, it is invoked at this
10100 ** The xDelete callback, if one is specified, is also invoked on the
10101 ** auxiliary data pointer after the FTS5 query has finished.
10103 ** If an error (e.g. an OOM condition) occurs within this function, an
10104 ** the auxiliary data is set to NULL and an error code returned. If the
10105 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
10106 ** pointer before returning.
10109 ** xGetAuxdata(pFts5, bClear)
10111 ** Returns the current auxiliary data pointer for the fts5 extension
10112 ** function. See the xSetAuxdata() method for details.
10114 ** If the bClear argument is non-zero, then the auxiliary data is cleared
10115 ** (set to NULL) before this function returns. In this case the xDelete,
10116 ** if any, is not invoked.
10119 ** xRowCount(pFts5, pnRow)
10121 ** This function is used to retrieve the total number of rows in the table.
10122 ** In other words, the same value that would be returned by:
10124 ** SELECT count(*) FROM ftstable;
10127 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
10128 ** method, to iterate through all instances of a single query phrase within
10129 ** the current row. This is the same information as is accessible via the
10130 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
10131 ** to use, this API may be faster under some circumstances. To iterate
10132 ** through instances of phrase iPhrase, use the following code:
10134 ** Fts5PhraseIter iter;
10136 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
10138 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
10140 ** // An instance of phrase iPhrase at offset iOff of column iCol
10143 ** The Fts5PhraseIter structure is defined above. Applications should not
10144 ** modify this structure directly - it should only be used as shown above
10145 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
10146 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
10148 ** This API can be quite slow if used with an FTS5 table created with the
10149 ** "detail=none" or "detail=column" option. If the FTS5 table is created
10150 ** with either "detail=none" or "detail=column" and "content=" option
10151 ** (i.e. if it is a contentless table), then this API always iterates
10152 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
10155 ** See xPhraseFirst above.
10157 ** xPhraseFirstColumn()
10158 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
10159 ** and xPhraseNext() APIs described above. The difference is that instead
10160 ** of iterating through all instances of a phrase in the current row, these
10161 ** APIs are used to iterate through the set of columns in the current row
10162 ** that contain one or more instances of a specified phrase. For example:
10164 ** Fts5PhraseIter iter;
10166 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
10168 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
10170 ** // Column iCol contains at least one instance of phrase iPhrase
10173 ** This API can be quite slow if used with an FTS5 table created with the
10174 ** "detail=none" option. If the FTS5 table is created with either
10175 ** "detail=none" "content=" option (i.e. if it is a contentless table),
10176 ** then this API always iterates through an empty set (all calls to
10177 ** xPhraseFirstColumn() set iCol to -1).
10179 ** The information accessed using this API and its companion
10180 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
10181 ** (or xInst/xInstCount). The chief advantage of this API is that it is
10182 ** significantly more efficient than those alternatives when used with
10183 ** "detail=column" tables.
10185 ** xPhraseNextColumn()
10186 ** See xPhraseFirstColumn above.
10188 struct Fts5ExtensionApi {
10189 int iVersion; /* Currently always set to 3 */
10191 void *(*xUserData)(Fts5Context*);
10193 int (*xColumnCount)(Fts5Context*);
10194 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
10195 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
10197 int (*xTokenize)(Fts5Context*,
10198 const char *pText, int nText, /* Text to tokenize */
10199 void *pCtx, /* Context passed to xToken() */
10200 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
10203 int (*xPhraseCount)(Fts5Context*);
10204 int (*xPhraseSize)(Fts5Context*, int iPhrase);
10206 int (*xInstCount)(Fts5Context*, int *pnInst);
10207 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
10209 sqlite3_int64 (*xRowid)(Fts5Context*);
10210 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
10211 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
10213 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
10214 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
10216 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
10217 void *(*xGetAuxdata)(Fts5Context*, int bClear);
10219 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
10220 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
10222 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
10223 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
10227 ** CUSTOM AUXILIARY FUNCTIONS
10228 *************************************************************************/
10230 /*************************************************************************
10231 ** CUSTOM TOKENIZERS
10233 ** Applications may also register custom tokenizer types. A tokenizer
10234 ** is registered by providing fts5 with a populated instance of the
10235 ** following structure. All structure methods must be defined, setting
10236 ** any member of the fts5_tokenizer struct to NULL leads to undefined
10237 ** behaviour. The structure methods are expected to function as follows:
10240 ** This function is used to allocate and initialize a tokenizer instance.
10241 ** A tokenizer instance is required to actually tokenize text.
10243 ** The first argument passed to this function is a copy of the (void*)
10244 ** pointer provided by the application when the fts5_tokenizer object
10245 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
10246 ** The second and third arguments are an array of nul-terminated strings
10247 ** containing the tokenizer arguments, if any, specified following the
10248 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
10249 ** to create the FTS5 table.
10251 ** The final argument is an output variable. If successful, (*ppOut)
10252 ** should be set to point to the new tokenizer handle and SQLITE_OK
10253 ** returned. If an error occurs, some value other than SQLITE_OK should
10254 ** be returned. In this case, fts5 assumes that the final value of *ppOut
10258 ** This function is invoked to delete a tokenizer handle previously
10259 ** allocated using xCreate(). Fts5 guarantees that this function will
10260 ** be invoked exactly once for each successful call to xCreate().
10263 ** This function is expected to tokenize the nText byte string indicated
10264 ** by argument pText. pText may or may not be nul-terminated. The first
10265 ** argument passed to this function is a pointer to an Fts5Tokenizer object
10266 ** returned by an earlier call to xCreate().
10268 ** The second argument indicates the reason that FTS5 is requesting
10269 ** tokenization of the supplied text. This is always one of the following
10272 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
10273 ** or removed from the FTS table. The tokenizer is being invoked to
10274 ** determine the set of tokens to add to (or delete from) the
10277 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
10278 ** against the FTS index. The tokenizer is being called to tokenize
10279 ** a bareword or quoted string specified as part of the query.
10281 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
10282 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
10283 ** followed by a "*" character, indicating that the last token
10284 ** returned by the tokenizer will be treated as a token prefix.
10286 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
10287 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
10288 ** function. Or an fts5_api.xColumnSize() request made by the same
10289 ** on a columnsize=0 database.
10292 ** For each token in the input string, the supplied callback xToken() must
10293 ** be invoked. The first argument to it should be a copy of the pointer
10294 ** passed as the second argument to xTokenize(). The third and fourth
10295 ** arguments are a pointer to a buffer containing the token text, and the
10296 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
10297 ** of the first byte of and first byte immediately following the text from
10298 ** which the token is derived within the input.
10300 ** The second argument passed to the xToken() callback ("tflags") should
10301 ** normally be set to 0. The exception is if the tokenizer supports
10302 ** synonyms. In this case see the discussion below for details.
10304 ** FTS5 assumes the xToken() callback is invoked for each token in the
10305 ** order that they occur within the input text.
10307 ** If an xToken() callback returns any value other than SQLITE_OK, then
10308 ** the tokenization should be abandoned and the xTokenize() method should
10309 ** immediately return a copy of the xToken() return value. Or, if the
10310 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
10311 ** if an error occurs with the xTokenize() implementation itself, it
10312 ** may abandon the tokenization and return any error code other than
10313 ** SQLITE_OK or SQLITE_DONE.
10317 ** Custom tokenizers may also support synonyms. Consider a case in which a
10318 ** user wishes to query for a phrase such as "first place". Using the
10319 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
10320 ** of "first place" within the document set, but not alternative forms
10321 ** such as "1st place". In some applications, it would be better to match
10322 ** all instances of "first place" or "1st place" regardless of which form
10323 ** the user specified in the MATCH query text.
10325 ** There are several ways to approach this in FTS5:
10327 ** <ol><li> By mapping all synonyms to a single token. In this case, the
10328 ** In the above example, this means that the tokenizer returns the
10329 ** same token for inputs "first" and "1st". Say that token is in
10330 ** fact "first", so that when the user inserts the document "I won
10331 ** 1st place" entries are added to the index for tokens "i", "won",
10332 ** "first" and "place". If the user then queries for '1st + place',
10333 ** the tokenizer substitutes "first" for "1st" and the query works
10336 ** <li> By adding multiple synonyms for a single term to the FTS index.
10337 ** In this case, when tokenizing query text, the tokenizer may
10338 ** provide multiple synonyms for a single term within the document.
10339 ** FTS5 then queries the index for each synonym individually. For
10340 ** example, faced with the query:
10343 ** ... MATCH 'first place'</codeblock>
10345 ** the tokenizer offers both "1st" and "first" as synonyms for the
10346 ** first token in the MATCH query and FTS5 effectively runs a query
10350 ** ... MATCH '(first OR 1st) place'</codeblock>
10352 ** except that, for the purposes of auxiliary functions, the query
10353 ** still appears to contain just two phrases - "(first OR 1st)"
10354 ** being treated as a single phrase.
10356 ** <li> By adding multiple synonyms for a single term to the FTS index.
10357 ** Using this method, when tokenizing document text, the tokenizer
10358 ** provides multiple synonyms for each token. So that when a
10359 ** document such as "I won first place" is tokenized, entries are
10360 ** added to the FTS index for "i", "won", "first", "1st" and
10363 ** This way, even if the tokenizer does not provide synonyms
10364 ** when tokenizing query text (it should not - to do would be
10365 ** inefficient), it doesn't matter if the user queries for
10366 ** 'first + place' or '1st + place', as there are entires in the
10367 ** FTS index corresponding to both forms of the first token.
10370 ** Whether it is parsing document or query text, any call to xToken that
10371 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
10372 ** is considered to supply a synonym for the previous token. For example,
10373 ** when parsing the document "I won first place", a tokenizer that supports
10374 ** synonyms would call xToken() 5 times, as follows:
10377 ** xToken(pCtx, 0, "i", 1, 0, 1);
10378 ** xToken(pCtx, 0, "won", 3, 2, 5);
10379 ** xToken(pCtx, 0, "first", 5, 6, 11);
10380 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
10381 ** xToken(pCtx, 0, "place", 5, 12, 17);
10384 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
10385 ** xToken() is called. Multiple synonyms may be specified for a single token
10386 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
10387 ** There is no limit to the number of synonyms that may be provided for a
10390 ** In many cases, method (1) above is the best approach. It does not add
10391 ** extra data to the FTS index or require FTS5 to query for multiple terms,
10392 ** so it is efficient in terms of disk space and query speed. However, it
10393 ** does not support prefix queries very well. If, as suggested above, the
10394 ** token "first" is subsituted for "1st" by the tokenizer, then the query:
10397 ** ... MATCH '1s*'</codeblock>
10399 ** will not match documents that contain the token "1st" (as the tokenizer
10400 ** will probably not map "1s" to any prefix of "first").
10402 ** For full prefix support, method (3) may be preferred. In this case,
10403 ** because the index contains entries for both "first" and "1st", prefix
10404 ** queries such as 'fi*' or '1s*' will match correctly. However, because
10405 ** extra entries are added to the FTS index, this method uses more space
10406 ** within the database.
10408 ** Method (2) offers a midpoint between (1) and (3). Using this method,
10409 ** a query such as '1s*' will match documents that contain the literal
10410 ** token "1st", but not "first" (assuming the tokenizer is not able to
10411 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
10412 ** will match against "1st" and "first". This method does not require
10413 ** extra disk space, as no extra entries are added to the FTS index.
10414 ** On the other hand, it may require more CPU cycles to run MATCH queries,
10415 ** as separate queries of the FTS index are required for each synonym.
10417 ** When using methods (2) or (3), it is important that the tokenizer only
10418 ** provide synonyms when tokenizing document text (method (2)) or query
10419 ** text (method (3)), not both. Doing so will not cause any errors, but is
10422 typedef struct Fts5Tokenizer Fts5Tokenizer;
10423 typedef struct fts5_tokenizer fts5_tokenizer;
10424 struct fts5_tokenizer {
10425 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
10426 void (*xDelete)(Fts5Tokenizer*);
10427 int (*xTokenize)(Fts5Tokenizer*,
10429 int flags, /* Mask of FTS5_TOKENIZE_* flags */
10430 const char *pText, int nText,
10432 void *pCtx, /* Copy of 2nd argument to xTokenize() */
10433 int tflags, /* Mask of FTS5_TOKEN_* flags */
10434 const char *pToken, /* Pointer to buffer containing token */
10435 int nToken, /* Size of token in bytes */
10436 int iStart, /* Byte offset of token within input text */
10437 int iEnd /* Byte offset of end of token within input text */
10442 /* Flags that may be passed as the third argument to xTokenize() */
10443 #define FTS5_TOKENIZE_QUERY 0x0001
10444 #define FTS5_TOKENIZE_PREFIX 0x0002
10445 #define FTS5_TOKENIZE_DOCUMENT 0x0004
10446 #define FTS5_TOKENIZE_AUX 0x0008
10448 /* Flags that may be passed by the tokenizer implementation back to FTS5
10449 ** as the third argument to the supplied xToken callback. */
10450 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
10453 ** END OF CUSTOM TOKENIZERS
10454 *************************************************************************/
10456 /*************************************************************************
10457 ** FTS5 EXTENSION REGISTRATION API
10459 typedef struct fts5_api fts5_api;
10461 int iVersion; /* Currently always set to 2 */
10463 /* Create a new tokenizer */
10464 int (*xCreateTokenizer)(
10468 fts5_tokenizer *pTokenizer,
10469 void (*xDestroy)(void*)
10472 /* Find an existing tokenizer */
10473 int (*xFindTokenizer)(
10477 fts5_tokenizer *pTokenizer
10480 /* Create a new auxiliary function */
10481 int (*xCreateFunction)(
10485 fts5_extension_function xFunction,
10486 void (*xDestroy)(void*)
10491 ** END OF REGISTRATION API
10492 *************************************************************************/
10495 } /* end of the 'extern "C"' block */
10498 #endif /* _FTS5_H */
10500 /******** End of fts5.h *********/