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Mon Feb 4 17:41:59 2013 UTC (7 years, 6 months ago) by zoff99
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new map version, lots of fixes and experimental new features
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
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.
10 **
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.
17 **
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.
23 **
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 suppose to operate.
27 **
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.
32 */
33 #ifndef _SQLITE3_H_
34 #define _SQLITE3_H_
35 #include <stdarg.h> /* Needed for the definition of va_list */
36
37 /*
38 ** Make sure we can call this stuff from C++.
39 */
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43
44
45 /*
46 ** Add the ability to override 'extern'
47 */
48 #ifndef SQLITE_EXTERN
49 # define SQLITE_EXTERN extern
50 #endif
51
52 #ifndef SQLITE_API
53 # define SQLITE_API
54 #endif
55
56
57 /*
58 ** These no-op macros are used in front of interfaces to mark those
59 ** interfaces as either deprecated or experimental. New applications
60 ** should not use deprecated interfaces - they are support for backwards
61 ** compatibility only. Application writers should be aware that
62 ** experimental interfaces are subject to change in point releases.
63 **
64 ** These macros used to resolve to various kinds of compiler magic that
65 ** would generate warning messages when they were used. But that
66 ** compiler magic ended up generating such a flurry of bug reports
67 ** that we have taken it all out and gone back to using simple
68 ** noop macros.
69 */
70 #define SQLITE_DEPRECATED
71 #define SQLITE_EXPERIMENTAL
72
73 /*
74 ** Ensure these symbols were not defined by some previous header file.
75 */
76 #ifdef SQLITE_VERSION
77 # undef SQLITE_VERSION
78 #endif
79 #ifdef SQLITE_VERSION_NUMBER
80 # undef SQLITE_VERSION_NUMBER
81 #endif
82
83 /*
84 ** CAPI3REF: Compile-Time Library Version Numbers
85 **
86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
87 ** evaluates to a string literal that is the SQLite version in the
88 ** format "X.Y.Z" where X is the major version number (always 3 for
89 ** SQLite3) and Y is the minor version number and Z is the release number.)^
90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
92 ** numbers used in [SQLITE_VERSION].)^
93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
94 ** be larger than the release from which it is derived. Either Y will
95 ** be held constant and Z will be incremented or else Y will be incremented
96 ** and Z will be reset to zero.
97 **
98 ** Since version 3.6.18, SQLite source code has been stored in the
99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
101 ** a string which identifies a particular check-in of SQLite
102 ** within its configuration management system. ^The SQLITE_SOURCE_ID
103 ** string contains the date and time of the check-in (UTC) and an SHA1
104 ** hash of the entire source tree.
105 **
106 ** See also: [sqlite3_libversion()],
107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
108 ** [sqlite_version()] and [sqlite_source_id()].
109 */
110 #define SQLITE_VERSION "3.7.15"
111 #define SQLITE_VERSION_NUMBER 3007015
112 #define SQLITE_SOURCE_ID "2012-11-09 21:40:02 5a3b07f0f5dfae7eea870303f52f37d6a17f1da2"
113
114 /*
115 ** CAPI3REF: Run-Time Library Version Numbers
116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
117 **
118 ** These interfaces provide the same information as the [SQLITE_VERSION],
119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
120 ** but are associated with the library instead of the header file. ^(Cautious
121 ** programmers might include assert() statements in their application to
122 ** verify that values returned by these interfaces match the macros in
123 ** the header, and thus insure that the application is
124 ** compiled with matching library and header files.
125 **
126 ** <blockquote><pre>
127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
130 ** </pre></blockquote>)^
131 **
132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
133 ** macro. ^The sqlite3_libversion() function returns a pointer to the
134 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
135 ** function is provided for use in DLLs since DLL users usually do not have
136 ** direct access to string constants within the DLL. ^The
137 ** sqlite3_libversion_number() function returns an integer equal to
138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
139 ** a pointer to a string constant whose value is the same as the
140 ** [SQLITE_SOURCE_ID] C preprocessor macro.
141 **
142 ** See also: [sqlite_version()] and [sqlite_source_id()].
143 */
144 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
145 SQLITE_API const char *sqlite3_libversion(void);
146 SQLITE_API const char *sqlite3_sourceid(void);
147 SQLITE_API int sqlite3_libversion_number(void);
148
149 /*
150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
151 **
152 ** ^The sqlite3_compileoption_used() function returns 0 or 1
153 ** indicating whether the specified option was defined at
154 ** compile time. ^The SQLITE_ prefix may be omitted from the
155 ** option name passed to sqlite3_compileoption_used().
156 **
157 ** ^The sqlite3_compileoption_get() function allows iterating
158 ** over the list of options that were defined at compile time by
159 ** returning the N-th compile time option string. ^If N is out of range,
160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
161 ** prefix is omitted from any strings returned by
162 ** sqlite3_compileoption_get().
163 **
164 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
165 ** and sqlite3_compileoption_get() may be omitted by specifying the
166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
167 **
168 ** See also: SQL functions [sqlite_compileoption_used()] and
169 ** [sqlite_compileoption_get()] and the [compile_options pragma].
170 */
171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
173 SQLITE_API const char *sqlite3_compileoption_get(int N);
174 #endif
175
176 /*
177 ** CAPI3REF: Test To See If The Library Is Threadsafe
178 **
179 ** ^The sqlite3_threadsafe() function returns zero if and only if
180 ** SQLite was compiled with mutexing code omitted due to the
181 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
182 **
183 ** SQLite can be compiled with or without mutexes. When
184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
185 ** are enabled and SQLite is threadsafe. When the
186 ** [SQLITE_THREADSAFE] macro is 0,
187 ** the mutexes are omitted. Without the mutexes, it is not safe
188 ** to use SQLite concurrently from more than one thread.
189 **
190 ** Enabling mutexes incurs a measurable performance penalty.
191 ** So if speed is of utmost importance, it makes sense to disable
192 ** the mutexes. But for maximum safety, mutexes should be enabled.
193 ** ^The default behavior is for mutexes to be enabled.
194 **
195 ** This interface can be used by an application to make sure that the
196 ** version of SQLite that it is linking against was compiled with
197 ** the desired setting of the [SQLITE_THREADSAFE] macro.
198 **
199 ** This interface only reports on the compile-time mutex setting
200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
202 ** can be fully or partially disabled using a call to [sqlite3_config()]
203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the
205 ** sqlite3_threadsafe() function shows only the compile-time setting of
206 ** thread safety, not any run-time changes to that setting made by
207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
208 ** is unchanged by calls to sqlite3_config().)^
209 **
210 ** See the [threading mode] documentation for additional information.
211 */
212 SQLITE_API int sqlite3_threadsafe(void);
213
214 /*
215 ** CAPI3REF: Database Connection Handle
216 ** KEYWORDS: {database connection} {database connections}
217 **
218 ** Each open SQLite database is represented by a pointer to an instance of
219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
222 ** and [sqlite3_close_v2()] are its destructors. There are many other
223 ** interfaces (such as
224 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
225 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
226 ** sqlite3 object.
227 */
228 typedef struct sqlite3 sqlite3;
229
230 /*
231 ** CAPI3REF: 64-Bit Integer Types
232 ** KEYWORDS: sqlite_int64 sqlite_uint64
233 **
234 ** Because there is no cross-platform way to specify 64-bit integer types
235 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
236 **
237 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
238 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
239 ** compatibility only.
240 **
241 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
242 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
243 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
244 ** between 0 and +18446744073709551615 inclusive.
245 */
246 #ifdef SQLITE_INT64_TYPE
247 typedef SQLITE_INT64_TYPE sqlite_int64;
248 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
249 #elif defined(_MSC_VER) || defined(__BORLANDC__)
250 typedef __int64 sqlite_int64;
251 typedef unsigned __int64 sqlite_uint64;
252 #else
253 typedef long long int sqlite_int64;
254 typedef unsigned long long int sqlite_uint64;
255 #endif
256 typedef sqlite_int64 sqlite3_int64;
257 typedef sqlite_uint64 sqlite3_uint64;
258
259 /*
260 ** If compiling for a processor that lacks floating point support,
261 ** substitute integer for floating-point.
262 */
263 #ifdef SQLITE_OMIT_FLOATING_POINT
264 # define double sqlite3_int64
265 #endif
266
267 /*
268 ** CAPI3REF: Closing A Database Connection
269 **
270 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
271 ** for the [sqlite3] object.
272 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return SQLITE_OK if
273 ** the [sqlite3] object is successfully destroyed and all associated
274 ** resources are deallocated.
275 **
276 ** ^If the database connection is associated with unfinalized prepared
277 ** statements or unfinished sqlite3_backup objects then sqlite3_close()
278 ** will leave the database connection open and return [SQLITE_BUSY].
279 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements
280 ** and unfinished sqlite3_backups, then the database connection becomes
281 ** an unusable "zombie" which will automatically be deallocated when the
282 ** last prepared statement is finalized or the last sqlite3_backup is
283 ** finished. The sqlite3_close_v2() interface is intended for use with
284 ** host languages that are garbage collected, and where the order in which
285 ** destructors are called is arbitrary.
286 **
287 ** Applications should [sqlite3_finalize | finalize] all [prepared statements],
288 ** [sqlite3_blob_close | close] all [BLOB handles], and
289 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
290 ** with the [sqlite3] object prior to attempting to close the object. ^If
291 ** sqlite3_close() is called on a [database connection] that still has
292 ** outstanding [prepared statements], [BLOB handles], and/or
293 ** [sqlite3_backup] objects then it returns SQLITE_OK but the deallocation
294 ** of resources is deferred until all [prepared statements], [BLOB handles],
295 ** and [sqlite3_backup] objects are also destroyed.
296 **
297 ** ^If an [sqlite3] object is destroyed while a transaction is open,
298 ** the transaction is automatically rolled back.
299 **
300 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
301 ** must be either a NULL
302 ** pointer or an [sqlite3] object pointer obtained
303 ** from [sqlite3_open()], [sqlite3_open16()], or
304 ** [sqlite3_open_v2()], and not previously closed.
305 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
306 ** argument is a harmless no-op.
307 */
308 SQLITE_API int sqlite3_close(sqlite3*);
309 SQLITE_API int sqlite3_close_v2(sqlite3*);
310
311 /*
312 ** The type for a callback function.
313 ** This is legacy and deprecated. It is included for historical
314 ** compatibility and is not documented.
315 */
316 typedef int (*sqlite3_callback)(void*,int,char**, char**);
317
318 /*
319 ** CAPI3REF: One-Step Query Execution Interface
320 **
321 ** The sqlite3_exec() interface is a convenience wrapper around
322 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
323 ** that allows an application to run multiple statements of SQL
324 ** without having to use a lot of C code.
325 **
326 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
327 ** semicolon-separate SQL statements passed into its 2nd argument,
328 ** in the context of the [database connection] passed in as its 1st
329 ** argument. ^If the callback function of the 3rd argument to
330 ** sqlite3_exec() is not NULL, then it is invoked for each result row
331 ** coming out of the evaluated SQL statements. ^The 4th argument to
332 ** sqlite3_exec() is relayed through to the 1st argument of each
333 ** callback invocation. ^If the callback pointer to sqlite3_exec()
334 ** is NULL, then no callback is ever invoked and result rows are
335 ** ignored.
336 **
337 ** ^If an error occurs while evaluating the SQL statements passed into
338 ** sqlite3_exec(), then execution of the current statement stops and
339 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
340 ** is not NULL then any error message is written into memory obtained
341 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
342 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
343 ** on error message strings returned through the 5th parameter of
344 ** of sqlite3_exec() after the error message string is no longer needed.
345 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
346 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
347 ** NULL before returning.
348 **
349 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
350 ** routine returns SQLITE_ABORT without invoking the callback again and
351 ** without running any subsequent SQL statements.
352 **
353 ** ^The 2nd argument to the sqlite3_exec() callback function is the
354 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
355 ** callback is an array of pointers to strings obtained as if from
356 ** [sqlite3_column_text()], one for each column. ^If an element of a
357 ** result row is NULL then the corresponding string pointer for the
358 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
359 ** sqlite3_exec() callback is an array of pointers to strings where each
360 ** entry represents the name of corresponding result column as obtained
361 ** from [sqlite3_column_name()].
362 **
363 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
364 ** to an empty string, or a pointer that contains only whitespace and/or
365 ** SQL comments, then no SQL statements are evaluated and the database
366 ** is not changed.
367 **
368 ** Restrictions:
369 **
370 ** <ul>
371 ** <li> The application must insure that the 1st parameter to sqlite3_exec()
372 ** is a valid and open [database connection].
373 ** <li> The application must not close [database connection] specified by
374 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
375 ** <li> The application must not modify the SQL statement text passed into
376 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
377 ** </ul>
378 */
379 SQLITE_API int sqlite3_exec(
380 sqlite3*, /* An open database */
381 const char *sql, /* SQL to be evaluated */
382 int (*callback)(void*,int,char**,char**), /* Callback function */
383 void *, /* 1st argument to callback */
384 char **errmsg /* Error msg written here */
385 );
386
387 /*
388 ** CAPI3REF: Result Codes
389 ** KEYWORDS: SQLITE_OK {error code} {error codes}
390 ** KEYWORDS: {result code} {result codes}
391 **
392 ** Many SQLite functions return an integer result code from the set shown
393 ** here in order to indicate success or failure.
394 **
395 ** New error codes may be added in future versions of SQLite.
396 **
397 ** See also: [SQLITE_IOERR_READ | extended result codes],
398 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes].
399 */
400 #define SQLITE_OK 0 /* Successful result */
401 /* beginning-of-error-codes */
402 #define SQLITE_ERROR 1 /* SQL error or missing database */
403 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
404 #define SQLITE_PERM 3 /* Access permission denied */
405 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
406 #define SQLITE_BUSY 5 /* The database file is locked */
407 #define SQLITE_LOCKED 6 /* A table in the database is locked */
408 #define SQLITE_NOMEM 7 /* A malloc() failed */
409 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
410 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
411 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
412 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
413 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
414 #define SQLITE_FULL 13 /* Insertion failed because database is full */
415 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
416 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
417 #define SQLITE_EMPTY 16 /* Database is empty */
418 #define SQLITE_SCHEMA 17 /* The database schema changed */
419 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
420 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
421 #define SQLITE_MISMATCH 20 /* Data type mismatch */
422 #define SQLITE_MISUSE 21 /* Library used incorrectly */
423 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
424 #define SQLITE_AUTH 23 /* Authorization denied */
425 #define SQLITE_FORMAT 24 /* Auxiliary database format error */
426 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
427 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
428 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
429 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
430 /* end-of-error-codes */
431
432 /*
433 ** CAPI3REF: Extended Result Codes
434 ** KEYWORDS: {extended error code} {extended error codes}
435 ** KEYWORDS: {extended result code} {extended result codes}
436 **
437 ** In its default configuration, SQLite API routines return one of 26 integer
438 ** [SQLITE_OK | result codes]. However, experience has shown that many of
439 ** these result codes are too coarse-grained. They do not provide as
440 ** much information about problems as programmers might like. In an effort to
441 ** address this, newer versions of SQLite (version 3.3.8 and later) include
442 ** support for additional result codes that provide more detailed information
443 ** about errors. The extended result codes are enabled or disabled
444 ** on a per database connection basis using the
445 ** [sqlite3_extended_result_codes()] API.
446 **
447 ** Some of the available extended result codes are listed here.
448 ** One may expect the number of extended result codes will be expand
449 ** over time. Software that uses extended result codes should expect
450 ** to see new result codes in future releases of SQLite.
451 **
452 ** The SQLITE_OK result code will never be extended. It will always
453 ** be exactly zero.
454 */
455 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
456 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
457 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
458 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
459 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
460 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
461 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
462 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
463 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
464 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
465 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
466 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
467 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
468 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
469 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
470 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
471 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
472 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
473 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
474 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
475 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
476 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
477 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
478 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
479 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
480 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
481 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
482 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
483 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
484 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
485 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
486 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
487
488 /*
489 ** CAPI3REF: Flags For File Open Operations
490 **
491 ** These bit values are intended for use in the
492 ** 3rd parameter to the [sqlite3_open_v2()] interface and
493 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
494 */
495 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
496 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
497 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
498 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
499 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
500 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
501 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
502 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
503 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
504 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
505 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
506 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
507 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
508 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
509 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
510 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
511 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
512 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
513 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
514 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
515
516 /* Reserved: 0x00F00000 */
517
518 /*
519 ** CAPI3REF: Device Characteristics
520 **
521 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
522 ** object returns an integer which is a vector of these
523 ** bit values expressing I/O characteristics of the mass storage
524 ** device that holds the file that the [sqlite3_io_methods]
525 ** refers to.
526 **
527 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
528 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
529 ** mean that writes of blocks that are nnn bytes in size and
530 ** are aligned to an address which is an integer multiple of
531 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
532 ** that when data is appended to a file, the data is appended
533 ** first then the size of the file is extended, never the other
534 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
535 ** information is written to disk in the same order as calls
536 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
537 ** after reboot following a crash or power loss, the only bytes in a
538 ** file that were written at the application level might have changed
539 ** and that adjacent bytes, even bytes within the same sector are
540 ** guaranteed to be unchanged.
541 */
542 #define SQLITE_IOCAP_ATOMIC 0x00000001
543 #define SQLITE_IOCAP_ATOMIC512 0x00000002
544 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
545 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
546 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
547 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
548 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
549 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
550 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
551 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
552 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
553 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
554 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
555
556 /*
557 ** CAPI3REF: File Locking Levels
558 **
559 ** SQLite uses one of these integer values as the second
560 ** argument to calls it makes to the xLock() and xUnlock() methods
561 ** of an [sqlite3_io_methods] object.
562 */
563 #define SQLITE_LOCK_NONE 0
564 #define SQLITE_LOCK_SHARED 1
565 #define SQLITE_LOCK_RESERVED 2
566 #define SQLITE_LOCK_PENDING 3
567 #define SQLITE_LOCK_EXCLUSIVE 4
568
569 /*
570 ** CAPI3REF: Synchronization Type Flags
571 **
572 ** When SQLite invokes the xSync() method of an
573 ** [sqlite3_io_methods] object it uses a combination of
574 ** these integer values as the second argument.
575 **
576 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
577 ** sync operation only needs to flush data to mass storage. Inode
578 ** information need not be flushed. If the lower four bits of the flag
579 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
580 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
581 ** to use Mac OS X style fullsync instead of fsync().
582 **
583 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
584 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
585 ** settings. The [synchronous pragma] determines when calls to the
586 ** xSync VFS method occur and applies uniformly across all platforms.
587 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
588 ** energetic or rigorous or forceful the sync operations are and
589 ** only make a difference on Mac OSX for the default SQLite code.
590 ** (Third-party VFS implementations might also make the distinction
591 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
592 ** operating systems natively supported by SQLite, only Mac OSX
593 ** cares about the difference.)
594 */
595 #define SQLITE_SYNC_NORMAL 0x00002
596 #define SQLITE_SYNC_FULL 0x00003
597 #define SQLITE_SYNC_DATAONLY 0x00010
598
599 /*
600 ** CAPI3REF: OS Interface Open File Handle
601 **
602 ** An [sqlite3_file] object represents an open file in the
603 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
604 ** implementations will
605 ** want to subclass this object by appending additional fields
606 ** for their own use. The pMethods entry is a pointer to an
607 ** [sqlite3_io_methods] object that defines methods for performing
608 ** I/O operations on the open file.
609 */
610 typedef struct sqlite3_file sqlite3_file;
611 struct sqlite3_file {
612 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
613 };
614
615 /*
616 ** CAPI3REF: OS Interface File Virtual Methods Object
617 **
618 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
619 ** [sqlite3_file] object (or, more commonly, a subclass of the
620 ** [sqlite3_file] object) with a pointer to an instance of this object.
621 ** This object defines the methods used to perform various operations
622 ** against the open file represented by the [sqlite3_file] object.
623 **
624 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
625 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
626 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
627 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
628 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
629 ** to NULL.
630 **
631 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
632 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
633 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
634 ** flag may be ORed in to indicate that only the data of the file
635 ** and not its inode needs to be synced.
636 **
637 ** The integer values to xLock() and xUnlock() are one of
638 ** <ul>
639 ** <li> [SQLITE_LOCK_NONE],
640 ** <li> [SQLITE_LOCK_SHARED],
641 ** <li> [SQLITE_LOCK_RESERVED],
642 ** <li> [SQLITE_LOCK_PENDING], or
643 ** <li> [SQLITE_LOCK_EXCLUSIVE].
644 ** </ul>
645 ** xLock() increases the lock. xUnlock() decreases the lock.
646 ** The xCheckReservedLock() method checks whether any database connection,
647 ** either in this process or in some other process, is holding a RESERVED,
648 ** PENDING, or EXCLUSIVE lock on the file. It returns true
649 ** if such a lock exists and false otherwise.
650 **
651 ** The xFileControl() method is a generic interface that allows custom
652 ** VFS implementations to directly control an open file using the
653 ** [sqlite3_file_control()] interface. The second "op" argument is an
654 ** integer opcode. The third argument is a generic pointer intended to
655 ** point to a structure that may contain arguments or space in which to
656 ** write return values. Potential uses for xFileControl() might be
657 ** functions to enable blocking locks with timeouts, to change the
658 ** locking strategy (for example to use dot-file locks), to inquire
659 ** about the status of a lock, or to break stale locks. The SQLite
660 ** core reserves all opcodes less than 100 for its own use.
661 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
662 ** Applications that define a custom xFileControl method should use opcodes
663 ** greater than 100 to avoid conflicts. VFS implementations should
664 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
665 ** recognize.
666 **
667 ** The xSectorSize() method returns the sector size of the
668 ** device that underlies the file. The sector size is the
669 ** minimum write that can be performed without disturbing
670 ** other bytes in the file. The xDeviceCharacteristics()
671 ** method returns a bit vector describing behaviors of the
672 ** underlying device:
673 **
674 ** <ul>
675 ** <li> [SQLITE_IOCAP_ATOMIC]
676 ** <li> [SQLITE_IOCAP_ATOMIC512]
677 ** <li> [SQLITE_IOCAP_ATOMIC1K]
678 ** <li> [SQLITE_IOCAP_ATOMIC2K]
679 ** <li> [SQLITE_IOCAP_ATOMIC4K]
680 ** <li> [SQLITE_IOCAP_ATOMIC8K]
681 ** <li> [SQLITE_IOCAP_ATOMIC16K]
682 ** <li> [SQLITE_IOCAP_ATOMIC32K]
683 ** <li> [SQLITE_IOCAP_ATOMIC64K]
684 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
685 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
686 ** </ul>
687 **
688 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
689 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
690 ** mean that writes of blocks that are nnn bytes in size and
691 ** are aligned to an address which is an integer multiple of
692 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
693 ** that when data is appended to a file, the data is appended
694 ** first then the size of the file is extended, never the other
695 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
696 ** information is written to disk in the same order as calls
697 ** to xWrite().
698 **
699 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
700 ** in the unread portions of the buffer with zeros. A VFS that
701 ** fails to zero-fill short reads might seem to work. However,
702 ** failure to zero-fill short reads will eventually lead to
703 ** database corruption.
704 */
705 typedef struct sqlite3_io_methods sqlite3_io_methods;
706 struct sqlite3_io_methods {
707 int iVersion;
708 int (*xClose)(sqlite3_file*);
709 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
710 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
711 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
712 int (*xSync)(sqlite3_file*, int flags);
713 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
714 int (*xLock)(sqlite3_file*, int);
715 int (*xUnlock)(sqlite3_file*, int);
716 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
717 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
718 int (*xSectorSize)(sqlite3_file*);
719 int (*xDeviceCharacteristics)(sqlite3_file*);
720 /* Methods above are valid for version 1 */
721 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
722 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
723 void (*xShmBarrier)(sqlite3_file*);
724 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
725 /* Methods above are valid for version 2 */
726 /* Additional methods may be added in future releases */
727 };
728
729 /*
730 ** CAPI3REF: Standard File Control Opcodes
731 **
732 ** These integer constants are opcodes for the xFileControl method
733 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
734 ** interface.
735 **
736 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
737 ** opcode causes the xFileControl method to write the current state of
738 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
739 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
740 ** into an integer that the pArg argument points to. This capability
741 ** is used during testing and only needs to be supported when SQLITE_TEST
742 ** is defined.
743 ** <ul>
744 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
745 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
746 ** layer a hint of how large the database file will grow to be during the
747 ** current transaction. This hint is not guaranteed to be accurate but it
748 ** is often close. The underlying VFS might choose to preallocate database
749 ** file space based on this hint in order to help writes to the database
750 ** file run faster.
751 **
752 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
753 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
754 ** extends and truncates the database file in chunks of a size specified
755 ** by the user. The fourth argument to [sqlite3_file_control()] should
756 ** point to an integer (type int) containing the new chunk-size to use
757 ** for the nominated database. Allocating database file space in large
758 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
759 ** improve performance on some systems.
760 **
761 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
762 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
763 ** to the [sqlite3_file] object associated with a particular database
764 ** connection. See the [sqlite3_file_control()] documentation for
765 ** additional information.
766 **
767 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
768 ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
769 ** SQLite and sent to all VFSes in place of a call to the xSync method
770 ** when the database connection has [PRAGMA synchronous] set to OFF.)^
771 ** Some specialized VFSes need this signal in order to operate correctly
772 ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most
773 ** VFSes do not need this signal and should silently ignore this opcode.
774 ** Applications should not call [sqlite3_file_control()] with this
775 ** opcode as doing so may disrupt the operation of the specialized VFSes
776 ** that do require it.
777 **
778 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
779 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
780 ** retry counts and intervals for certain disk I/O operations for the
781 ** windows [VFS] in order to provide robustness in the presence of
782 ** anti-virus programs. By default, the windows VFS will retry file read,
783 ** file write, and file delete operations up to 10 times, with a delay
784 ** of 25 milliseconds before the first retry and with the delay increasing
785 ** by an additional 25 milliseconds with each subsequent retry. This
786 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
787 ** to be adjusted. The values are changed for all database connections
788 ** within the same process. The argument is a pointer to an array of two
789 ** integers where the first integer i the new retry count and the second
790 ** integer is the delay. If either integer is negative, then the setting
791 ** is not changed but instead the prior value of that setting is written
792 ** into the array entry, allowing the current retry settings to be
793 ** interrogated. The zDbName parameter is ignored.
794 **
795 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
796 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
797 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
798 ** write ahead log and shared memory files used for transaction control
799 ** are automatically deleted when the latest connection to the database
800 ** closes. Setting persistent WAL mode causes those files to persist after
801 ** close. Persisting the files is useful when other processes that do not
802 ** have write permission on the directory containing the database file want
803 ** to read the database file, as the WAL and shared memory files must exist
804 ** in order for the database to be readable. The fourth parameter to
805 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
806 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
807 ** WAL mode. If the integer is -1, then it is overwritten with the current
808 ** WAL persistence setting.
809 **
810 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
811 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
812 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
813 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
814 ** xDeviceCharacteristics methods. The fourth parameter to
815 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
816 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
817 ** mode. If the integer is -1, then it is overwritten with the current
818 ** zero-damage mode setting.
819 **
820 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
821 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
822 ** a write transaction to indicate that, unless it is rolled back for some
823 ** reason, the entire database file will be overwritten by the current
824 ** transaction. This is used by VACUUM operations.
825 **
826 ** <li>[[SQLITE_FCNTL_VFSNAME]]
827 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
828 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
829 ** final bottom-level VFS are written into memory obtained from
830 ** [sqlite3_malloc()] and the result is stored in the char* variable
831 ** that the fourth parameter of [sqlite3_file_control()] points to.
832 ** The caller is responsible for freeing the memory when done. As with
833 ** all file-control actions, there is no guarantee that this will actually
834 ** do anything. Callers should initialize the char* variable to a NULL
835 ** pointer in case this file-control is not implemented. This file-control
836 ** is intended for diagnostic use only.
837 **
838 ** <li>[[SQLITE_FCNTL_PRAGMA]]
839 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
840 ** file control is sent to the open [sqlite3_file] object corresponding
841 ** to the database file to which the pragma statement refers. ^The argument
842 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
843 ** pointers to strings (char**) in which the second element of the array
844 ** is the name of the pragma and the third element is the argument to the
845 ** pragma or NULL if the pragma has no argument. ^The handler for an
846 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
847 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
848 ** or the equivalent and that string will become the result of the pragma or
849 ** the error message if the pragma fails. ^If the
850 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
851 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
852 ** file control returns [SQLITE_OK], then the parser assumes that the
853 ** VFS has handled the PRAGMA itself and the parser generates a no-op
854 ** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns
855 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
856 ** that the VFS encountered an error while handling the [PRAGMA] and the
857 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
858 ** file control occurs at the beginning of pragma statement analysis and so
859 ** it is able to override built-in [PRAGMA] statements.
860 ** </ul>
861 **
862 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
863 ** ^This file-control may be invoked by SQLite on the database file handle
864 ** shortly after it is opened in order to provide a custom VFS with access
865 ** to the connections busy-handler callback. The argument is of type (void **)
866 ** - an array of two (void *) values. The first (void *) actually points
867 ** to a function of type (int (*)(void *)). In order to invoke the connections
868 ** busy-handler, this function should be invoked with the second (void *) in
869 ** the array as the only argument. If it returns non-zero, then the operation
870 ** should be retried. If it returns zero, the custom VFS should abandon the
871 ** current operation.
872 */
873 #define SQLITE_FCNTL_LOCKSTATE 1
874 #define SQLITE_GET_LOCKPROXYFILE 2
875 #define SQLITE_SET_LOCKPROXYFILE 3
876 #define SQLITE_LAST_ERRNO 4
877 #define SQLITE_FCNTL_SIZE_HINT 5
878 #define SQLITE_FCNTL_CHUNK_SIZE 6
879 #define SQLITE_FCNTL_FILE_POINTER 7
880 #define SQLITE_FCNTL_SYNC_OMITTED 8
881 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
882 #define SQLITE_FCNTL_PERSIST_WAL 10
883 #define SQLITE_FCNTL_OVERWRITE 11
884 #define SQLITE_FCNTL_VFSNAME 12
885 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
886 #define SQLITE_FCNTL_PRAGMA 14
887 #define SQLITE_FCNTL_BUSYHANDLER 15
888
889 /*
890 ** CAPI3REF: Mutex Handle
891 **
892 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
893 ** abstract type for a mutex object. The SQLite core never looks
894 ** at the internal representation of an [sqlite3_mutex]. It only
895 ** deals with pointers to the [sqlite3_mutex] object.
896 **
897 ** Mutexes are created using [sqlite3_mutex_alloc()].
898 */
899 typedef struct sqlite3_mutex sqlite3_mutex;
900
901 /*
902 ** CAPI3REF: OS Interface Object
903 **
904 ** An instance of the sqlite3_vfs object defines the interface between
905 ** the SQLite core and the underlying operating system. The "vfs"
906 ** in the name of the object stands for "virtual file system". See
907 ** the [VFS | VFS documentation] for further information.
908 **
909 ** The value of the iVersion field is initially 1 but may be larger in
910 ** future versions of SQLite. Additional fields may be appended to this
911 ** object when the iVersion value is increased. Note that the structure
912 ** of the sqlite3_vfs object changes in the transaction between
913 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
914 ** modified.
915 **
916 ** The szOsFile field is the size of the subclassed [sqlite3_file]
917 ** structure used by this VFS. mxPathname is the maximum length of
918 ** a pathname in this VFS.
919 **
920 ** Registered sqlite3_vfs objects are kept on a linked list formed by
921 ** the pNext pointer. The [sqlite3_vfs_register()]
922 ** and [sqlite3_vfs_unregister()] interfaces manage this list
923 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
924 ** searches the list. Neither the application code nor the VFS
925 ** implementation should use the pNext pointer.
926 **
927 ** The pNext field is the only field in the sqlite3_vfs
928 ** structure that SQLite will ever modify. SQLite will only access
929 ** or modify this field while holding a particular static mutex.
930 ** The application should never modify anything within the sqlite3_vfs
931 ** object once the object has been registered.
932 **
933 ** The zName field holds the name of the VFS module. The name must
934 ** be unique across all VFS modules.
935 **
936 ** [[sqlite3_vfs.xOpen]]
937 ** ^SQLite guarantees that the zFilename parameter to xOpen
938 ** is either a NULL pointer or string obtained
939 ** from xFullPathname() with an optional suffix added.
940 ** ^If a suffix is added to the zFilename parameter, it will
941 ** consist of a single "-" character followed by no more than
942 ** 11 alphanumeric and/or "-" characters.
943 ** ^SQLite further guarantees that
944 ** the string will be valid and unchanged until xClose() is
945 ** called. Because of the previous sentence,
946 ** the [sqlite3_file] can safely store a pointer to the
947 ** filename if it needs to remember the filename for some reason.
948 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
949 ** must invent its own temporary name for the file. ^Whenever the
950 ** xFilename parameter is NULL it will also be the case that the
951 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
952 **
953 ** The flags argument to xOpen() includes all bits set in
954 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
955 ** or [sqlite3_open16()] is used, then flags includes at least
956 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
957 ** If xOpen() opens a file read-only then it sets *pOutFlags to
958 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
959 **
960 ** ^(SQLite will also add one of the following flags to the xOpen()
961 ** call, depending on the object being opened:
962 **
963 ** <ul>
964 ** <li> [SQLITE_OPEN_MAIN_DB]
965 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
966 ** <li> [SQLITE_OPEN_TEMP_DB]
967 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
968 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
969 ** <li> [SQLITE_OPEN_SUBJOURNAL]
970 ** <li> [SQLITE_OPEN_MASTER_JOURNAL]
971 ** <li> [SQLITE_OPEN_WAL]
972 ** </ul>)^
973 **
974 ** The file I/O implementation can use the object type flags to
975 ** change the way it deals with files. For example, an application
976 ** that does not care about crash recovery or rollback might make
977 ** the open of a journal file a no-op. Writes to this journal would
978 ** also be no-ops, and any attempt to read the journal would return
979 ** SQLITE_IOERR. Or the implementation might recognize that a database
980 ** file will be doing page-aligned sector reads and writes in a random
981 ** order and set up its I/O subsystem accordingly.
982 **
983 ** SQLite might also add one of the following flags to the xOpen method:
984 **
985 ** <ul>
986 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
987 ** <li> [SQLITE_OPEN_EXCLUSIVE]
988 ** </ul>
989 **
990 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
991 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
992 ** will be set for TEMP databases and their journals, transient
993 ** databases, and subjournals.
994 **
995 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
996 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
997 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
998 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
999 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1000 ** be created, and that it is an error if it already exists.
1001 ** It is <i>not</i> used to indicate the file should be opened
1002 ** for exclusive access.
1003 **
1004 ** ^At least szOsFile bytes of memory are allocated by SQLite
1005 ** to hold the [sqlite3_file] structure passed as the third
1006 ** argument to xOpen. The xOpen method does not have to
1007 ** allocate the structure; it should just fill it in. Note that
1008 ** the xOpen method must set the sqlite3_file.pMethods to either
1009 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1010 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1011 ** element will be valid after xOpen returns regardless of the success
1012 ** or failure of the xOpen call.
1013 **
1014 ** [[sqlite3_vfs.xAccess]]
1015 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1016 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1017 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1018 ** to test whether a file is at least readable. The file can be a
1019 ** directory.
1020 **
1021 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1022 ** output buffer xFullPathname. The exact size of the output buffer
1023 ** is also passed as a parameter to both methods. If the output buffer
1024 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1025 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1026 ** to prevent this by setting mxPathname to a sufficiently large value.
1027 **
1028 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1029 ** interfaces are not strictly a part of the filesystem, but they are
1030 ** included in the VFS structure for completeness.
1031 ** The xRandomness() function attempts to return nBytes bytes
1032 ** of good-quality randomness into zOut. The return value is
1033 ** the actual number of bytes of randomness obtained.
1034 ** The xSleep() method causes the calling thread to sleep for at
1035 ** least the number of microseconds given. ^The xCurrentTime()
1036 ** method returns a Julian Day Number for the current date and time as
1037 ** a floating point value.
1038 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1039 ** Day Number multiplied by 86400000 (the number of milliseconds in
1040 ** a 24-hour day).
1041 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1042 ** date and time if that method is available (if iVersion is 2 or
1043 ** greater and the function pointer is not NULL) and will fall back
1044 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1045 **
1046 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1047 ** are not used by the SQLite core. These optional interfaces are provided
1048 ** by some VFSes to facilitate testing of the VFS code. By overriding
1049 ** system calls with functions under its control, a test program can
1050 ** simulate faults and error conditions that would otherwise be difficult
1051 ** or impossible to induce. The set of system calls that can be overridden
1052 ** varies from one VFS to another, and from one version of the same VFS to the
1053 ** next. Applications that use these interfaces must be prepared for any
1054 ** or all of these interfaces to be NULL or for their behavior to change
1055 ** from one release to the next. Applications must not attempt to access
1056 ** any of these methods if the iVersion of the VFS is less than 3.
1057 */
1058 typedef struct sqlite3_vfs sqlite3_vfs;
1059 typedef void (*sqlite3_syscall_ptr)(void);
1060 struct sqlite3_vfs {
1061 int iVersion; /* Structure version number (currently 3) */
1062 int szOsFile; /* Size of subclassed sqlite3_file */
1063 int mxPathname; /* Maximum file pathname length */
1064 sqlite3_vfs *pNext; /* Next registered VFS */
1065 const char *zName; /* Name of this virtual file system */
1066 void *pAppData; /* Pointer to application-specific data */
1067 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1068 int flags, int *pOutFlags);
1069 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1070 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1071 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1072 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1073 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1074 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1075 void (*xDlClose)(sqlite3_vfs*, void*);
1076 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1077 int (*xSleep)(sqlite3_vfs*, int microseconds);
1078 int (*xCurrentTime)(sqlite3_vfs*, double*);
1079 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1080 /*
1081 ** The methods above are in version 1 of the sqlite_vfs object
1082 ** definition. Those that follow are added in version 2 or later
1083 */
1084 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1085 /*
1086 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1087 ** Those below are for version 3 and greater.
1088 */
1089 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1090 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1091 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1092 /*
1093 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1094 ** New fields may be appended in figure versions. The iVersion
1095 ** value will increment whenever this happens.
1096 */
1097 };
1098
1099 /*
1100 ** CAPI3REF: Flags for the xAccess VFS method
1101 **
1102 ** These integer constants can be used as the third parameter to
1103 ** the xAccess method of an [sqlite3_vfs] object. They determine
1104 ** what kind of permissions the xAccess method is looking for.
1105 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1106 ** simply checks whether the file exists.
1107 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1108 ** checks whether the named directory is both readable and writable
1109 ** (in other words, if files can be added, removed, and renamed within
1110 ** the directory).
1111 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1112 ** [temp_store_directory pragma], though this could change in a future
1113 ** release of SQLite.
1114 ** With SQLITE_ACCESS_READ, the xAccess method
1115 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1116 ** currently unused, though it might be used in a future release of
1117 ** SQLite.
1118 */
1119 #define SQLITE_ACCESS_EXISTS 0
1120 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1121 #define SQLITE_ACCESS_READ 2 /* Unused */
1122
1123 /*
1124 ** CAPI3REF: Flags for the xShmLock VFS method
1125 **
1126 ** These integer constants define the various locking operations
1127 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1128 ** following are the only legal combinations of flags to the
1129 ** xShmLock method:
1130 **
1131 ** <ul>
1132 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1133 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1134 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1135 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1136 ** </ul>
1137 **
1138 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1139 ** was given no the corresponding lock.
1140 **
1141 ** The xShmLock method can transition between unlocked and SHARED or
1142 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1143 ** and EXCLUSIVE.
1144 */
1145 #define SQLITE_SHM_UNLOCK 1
1146 #define SQLITE_SHM_LOCK 2
1147 #define SQLITE_SHM_SHARED 4
1148 #define SQLITE_SHM_EXCLUSIVE 8
1149
1150 /*
1151 ** CAPI3REF: Maximum xShmLock index
1152 **
1153 ** The xShmLock method on [sqlite3_io_methods] may use values
1154 ** between 0 and this upper bound as its "offset" argument.
1155 ** The SQLite core will never attempt to acquire or release a
1156 ** lock outside of this range
1157 */
1158 #define SQLITE_SHM_NLOCK 8
1159
1160
1161 /*
1162 ** CAPI3REF: Initialize The SQLite Library
1163 **
1164 ** ^The sqlite3_initialize() routine initializes the
1165 ** SQLite library. ^The sqlite3_shutdown() routine
1166 ** deallocates any resources that were allocated by sqlite3_initialize().
1167 ** These routines are designed to aid in process initialization and
1168 ** shutdown on embedded systems. Workstation applications using
1169 ** SQLite normally do not need to invoke either of these routines.
1170 **
1171 ** A call to sqlite3_initialize() is an "effective" call if it is
1172 ** the first time sqlite3_initialize() is invoked during the lifetime of
1173 ** the process, or if it is the first time sqlite3_initialize() is invoked
1174 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1175 ** of sqlite3_initialize() does any initialization. All other calls
1176 ** are harmless no-ops.)^
1177 **
1178 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1179 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1180 ** an effective call to sqlite3_shutdown() does any deinitialization.
1181 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1182 **
1183 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1184 ** is not. The sqlite3_shutdown() interface must only be called from a
1185 ** single thread. All open [database connections] must be closed and all
1186 ** other SQLite resources must be deallocated prior to invoking
1187 ** sqlite3_shutdown().
1188 **
1189 ** Among other things, ^sqlite3_initialize() will invoke
1190 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1191 ** will invoke sqlite3_os_end().
1192 **
1193 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1194 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1195 ** the library (perhaps it is unable to allocate a needed resource such
1196 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1197 **
1198 ** ^The sqlite3_initialize() routine is called internally by many other
1199 ** SQLite interfaces so that an application usually does not need to
1200 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1201 ** calls sqlite3_initialize() so the SQLite library will be automatically
1202 ** initialized when [sqlite3_open()] is called if it has not be initialized
1203 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1204 ** compile-time option, then the automatic calls to sqlite3_initialize()
1205 ** are omitted and the application must call sqlite3_initialize() directly
1206 ** prior to using any other SQLite interface. For maximum portability,
1207 ** it is recommended that applications always invoke sqlite3_initialize()
1208 ** directly prior to using any other SQLite interface. Future releases
1209 ** of SQLite may require this. In other words, the behavior exhibited
1210 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1211 ** default behavior in some future release of SQLite.
1212 **
1213 ** The sqlite3_os_init() routine does operating-system specific
1214 ** initialization of the SQLite library. The sqlite3_os_end()
1215 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1216 ** performed by these routines include allocation or deallocation
1217 ** of static resources, initialization of global variables,
1218 ** setting up a default [sqlite3_vfs] module, or setting up
1219 ** a default configuration using [sqlite3_config()].
1220 **
1221 ** The application should never invoke either sqlite3_os_init()
1222 ** or sqlite3_os_end() directly. The application should only invoke
1223 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1224 ** interface is called automatically by sqlite3_initialize() and
1225 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1226 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1227 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1228 ** When [custom builds | built for other platforms]
1229 ** (using the [SQLITE_OS_OTHER=1] compile-time
1230 ** option) the application must supply a suitable implementation for
1231 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1232 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1233 ** must return [SQLITE_OK] on success and some other [error code] upon
1234 ** failure.
1235 */
1236 SQLITE_API int sqlite3_initialize(void);
1237 SQLITE_API int sqlite3_shutdown(void);
1238 SQLITE_API int sqlite3_os_init(void);
1239 SQLITE_API int sqlite3_os_end(void);
1240
1241 /*
1242 ** CAPI3REF: Configuring The SQLite Library
1243 **
1244 ** The sqlite3_config() interface is used to make global configuration
1245 ** changes to SQLite in order to tune SQLite to the specific needs of
1246 ** the application. The default configuration is recommended for most
1247 ** applications and so this routine is usually not necessary. It is
1248 ** provided to support rare applications with unusual needs.
1249 **
1250 ** The sqlite3_config() interface is not threadsafe. The application
1251 ** must insure that no other SQLite interfaces are invoked by other
1252 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config()
1253 ** may only be invoked prior to library initialization using
1254 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1255 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1256 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1257 ** Note, however, that ^sqlite3_config() can be called as part of the
1258 ** implementation of an application-defined [sqlite3_os_init()].
1259 **
1260 ** The first argument to sqlite3_config() is an integer
1261 ** [configuration option] that determines
1262 ** what property of SQLite is to be configured. Subsequent arguments
1263 ** vary depending on the [configuration option]
1264 ** in the first argument.
1265 **
1266 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1267 ** ^If the option is unknown or SQLite is unable to set the option
1268 ** then this routine returns a non-zero [error code].
1269 */
1270 SQLITE_API int sqlite3_config(int, ...);
1271
1272 /*
1273 ** CAPI3REF: Configure database connections
1274 **
1275 ** The sqlite3_db_config() interface is used to make configuration
1276 ** changes to a [database connection]. The interface is similar to
1277 ** [sqlite3_config()] except that the changes apply to a single
1278 ** [database connection] (specified in the first argument).
1279 **
1280 ** The second argument to sqlite3_db_config(D,V,...) is the
1281 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1282 ** that indicates what aspect of the [database connection] is being configured.
1283 ** Subsequent arguments vary depending on the configuration verb.
1284 **
1285 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1286 ** the call is considered successful.
1287 */
1288 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1289
1290 /*
1291 ** CAPI3REF: Memory Allocation Routines
1292 **
1293 ** An instance of this object defines the interface between SQLite
1294 ** and low-level memory allocation routines.
1295 **
1296 ** This object is used in only one place in the SQLite interface.
1297 ** A pointer to an instance of this object is the argument to
1298 ** [sqlite3_config()] when the configuration option is
1299 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1300 ** By creating an instance of this object
1301 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1302 ** during configuration, an application can specify an alternative
1303 ** memory allocation subsystem for SQLite to use for all of its
1304 ** dynamic memory needs.
1305 **
1306 ** Note that SQLite comes with several [built-in memory allocators]
1307 ** that are perfectly adequate for the overwhelming majority of applications
1308 ** and that this object is only useful to a tiny minority of applications
1309 ** with specialized memory allocation requirements. This object is
1310 ** also used during testing of SQLite in order to specify an alternative
1311 ** memory allocator that simulates memory out-of-memory conditions in
1312 ** order to verify that SQLite recovers gracefully from such
1313 ** conditions.
1314 **
1315 ** The xMalloc, xRealloc, and xFree methods must work like the
1316 ** malloc(), realloc() and free() functions from the standard C library.
1317 ** ^SQLite guarantees that the second argument to
1318 ** xRealloc is always a value returned by a prior call to xRoundup.
1319 **
1320 ** xSize should return the allocated size of a memory allocation
1321 ** previously obtained from xMalloc or xRealloc. The allocated size
1322 ** is always at least as big as the requested size but may be larger.
1323 **
1324 ** The xRoundup method returns what would be the allocated size of
1325 ** a memory allocation given a particular requested size. Most memory
1326 ** allocators round up memory allocations at least to the next multiple
1327 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1328 ** Every memory allocation request coming in through [sqlite3_malloc()]
1329 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1330 ** that causes the corresponding memory allocation to fail.
1331 **
1332 ** The xInit method initializes the memory allocator. (For example,
1333 ** it might allocate any require mutexes or initialize internal data
1334 ** structures. The xShutdown method is invoked (indirectly) by
1335 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1336 ** by xInit. The pAppData pointer is used as the only parameter to
1337 ** xInit and xShutdown.
1338 **
1339 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1340 ** the xInit method, so the xInit method need not be threadsafe. The
1341 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1342 ** not need to be threadsafe either. For all other methods, SQLite
1343 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1344 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1345 ** it is by default) and so the methods are automatically serialized.
1346 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1347 ** methods must be threadsafe or else make their own arrangements for
1348 ** serialization.
1349 **
1350 ** SQLite will never invoke xInit() more than once without an intervening
1351 ** call to xShutdown().
1352 */
1353 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1354 struct sqlite3_mem_methods {
1355 void *(*xMalloc)(int); /* Memory allocation function */
1356 void (*xFree)(void*); /* Free a prior allocation */
1357 void *(*xRealloc)(void*,int); /* Resize an allocation */
1358 int (*xSize)(void*); /* Return the size of an allocation */
1359 int (*xRoundup)(int); /* Round up request size to allocation size */
1360 int (*xInit)(void*); /* Initialize the memory allocator */
1361 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1362 void *pAppData; /* Argument to xInit() and xShutdown() */
1363 };
1364
1365 /*
1366 ** CAPI3REF: Configuration Options
1367 ** KEYWORDS: {configuration option}
1368 **
1369 ** These constants are the available integer configuration options that
1370 ** can be passed as the first argument to the [sqlite3_config()] interface.
1371 **
1372 ** New configuration options may be added in future releases of SQLite.
1373 ** Existing configuration options might be discontinued. Applications
1374 ** should check the return code from [sqlite3_config()] to make sure that
1375 ** the call worked. The [sqlite3_config()] interface will return a
1376 ** non-zero [error code] if a discontinued or unsupported configuration option
1377 ** is invoked.
1378 **
1379 ** <dl>
1380 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1381 ** <dd>There are no arguments to this option. ^This option sets the
1382 ** [threading mode] to Single-thread. In other words, it disables
1383 ** all mutexing and puts SQLite into a mode where it can only be used
1384 ** by a single thread. ^If SQLite is compiled with
1385 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1386 ** it is not possible to change the [threading mode] from its default
1387 ** value of Single-thread and so [sqlite3_config()] will return
1388 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1389 ** configuration option.</dd>
1390 **
1391 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1392 ** <dd>There are no arguments to this option. ^This option sets the
1393 ** [threading mode] to Multi-thread. In other words, it disables
1394 ** mutexing on [database connection] and [prepared statement] objects.
1395 ** The application is responsible for serializing access to
1396 ** [database connections] and [prepared statements]. But other mutexes
1397 ** are enabled so that SQLite will be safe to use in a multi-threaded
1398 ** environment as long as no two threads attempt to use the same
1399 ** [database connection] at the same time. ^If SQLite is compiled with
1400 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1401 ** it is not possible to set the Multi-thread [threading mode] and
1402 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1403 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1404 **
1405 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1406 ** <dd>There are no arguments to this option. ^This option sets the
1407 ** [threading mode] to Serialized. In other words, this option enables
1408 ** all mutexes including the recursive
1409 ** mutexes on [database connection] and [prepared statement] objects.
1410 ** In this mode (which is the default when SQLite is compiled with
1411 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1412 ** to [database connections] and [prepared statements] so that the
1413 ** application is free to use the same [database connection] or the
1414 ** same [prepared statement] in different threads at the same time.
1415 ** ^If SQLite is compiled with
1416 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1417 ** it is not possible to set the Serialized [threading mode] and
1418 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1419 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1420 **
1421 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1422 ** <dd> ^(This option takes a single argument which is a pointer to an
1423 ** instance of the [sqlite3_mem_methods] structure. The argument specifies
1424 ** alternative low-level memory allocation routines to be used in place of
1425 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1426 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1427 ** before the [sqlite3_config()] call returns.</dd>
1428 **
1429 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1430 ** <dd> ^(This option takes a single argument which is a pointer to an
1431 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods]
1432 ** structure is filled with the currently defined memory allocation routines.)^
1433 ** This option can be used to overload the default memory allocation
1434 ** routines with a wrapper that simulations memory allocation failure or
1435 ** tracks memory usage, for example. </dd>
1436 **
1437 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1438 ** <dd> ^This option takes single argument of type int, interpreted as a
1439 ** boolean, which enables or disables the collection of memory allocation
1440 ** statistics. ^(When memory allocation statistics are disabled, the
1441 ** following SQLite interfaces become non-operational:
1442 ** <ul>
1443 ** <li> [sqlite3_memory_used()]
1444 ** <li> [sqlite3_memory_highwater()]
1445 ** <li> [sqlite3_soft_heap_limit64()]
1446 ** <li> [sqlite3_status()]
1447 ** </ul>)^
1448 ** ^Memory allocation statistics are enabled by default unless SQLite is
1449 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1450 ** allocation statistics are disabled by default.
1451 ** </dd>
1452 **
1453 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1454 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1455 ** scratch memory. There are three arguments: A pointer an 8-byte
1456 ** aligned memory buffer from which the scratch allocations will be
1457 ** drawn, the size of each scratch allocation (sz),
1458 ** and the maximum number of scratch allocations (N). The sz
1459 ** argument must be a multiple of 16.
1460 ** The first argument must be a pointer to an 8-byte aligned buffer
1461 ** of at least sz*N bytes of memory.
1462 ** ^SQLite will use no more than two scratch buffers per thread. So
1463 ** N should be set to twice the expected maximum number of threads.
1464 ** ^SQLite will never require a scratch buffer that is more than 6
1465 ** times the database page size. ^If SQLite needs needs additional
1466 ** scratch memory beyond what is provided by this configuration option, then
1467 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>
1468 **
1469 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1470 ** <dd> ^This option specifies a static memory buffer that SQLite can use for
1471 ** the database page cache with the default page cache implementation.
1472 ** This configuration should not be used if an application-define page
1473 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option.
1474 ** There are three arguments to this option: A pointer to 8-byte aligned
1475 ** memory, the size of each page buffer (sz), and the number of pages (N).
1476 ** The sz argument should be the size of the largest database page
1477 ** (a power of two between 512 and 32768) plus a little extra for each
1478 ** page header. ^The page header size is 20 to 40 bytes depending on
1479 ** the host architecture. ^It is harmless, apart from the wasted memory,
1480 ** to make sz a little too large. The first
1481 ** argument should point to an allocation of at least sz*N bytes of memory.
1482 ** ^SQLite will use the memory provided by the first argument to satisfy its
1483 ** memory needs for the first N pages that it adds to cache. ^If additional
1484 ** page cache memory is needed beyond what is provided by this option, then
1485 ** SQLite goes to [sqlite3_malloc()] for the additional storage space.
1486 ** The pointer in the first argument must
1487 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite
1488 ** will be undefined.</dd>
1489 **
1490 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1491 ** <dd> ^This option specifies a static memory buffer that SQLite will use
1492 ** for all of its dynamic memory allocation needs beyond those provided
1493 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
1494 ** There are three arguments: An 8-byte aligned pointer to the memory,
1495 ** the number of bytes in the memory buffer, and the minimum allocation size.
1496 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1497 ** to using its default memory allocator (the system malloc() implementation),
1498 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1499 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
1500 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
1501 ** allocator is engaged to handle all of SQLites memory allocation needs.
1502 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1503 ** boundary or subsequent behavior of SQLite will be undefined.
1504 ** The minimum allocation size is capped at 2**12. Reasonable values
1505 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1506 **
1507 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1508 ** <dd> ^(This option takes a single argument which is a pointer to an
1509 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies
1510 ** alternative low-level mutex routines to be used in place
1511 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the
1512 ** content of the [sqlite3_mutex_methods] structure before the call to
1513 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1514 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1515 ** the entire mutexing subsystem is omitted from the build and hence calls to
1516 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1517 ** return [SQLITE_ERROR].</dd>
1518 **
1519 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1520 ** <dd> ^(This option takes a single argument which is a pointer to an
1521 ** instance of the [sqlite3_mutex_methods] structure. The
1522 ** [sqlite3_mutex_methods]
1523 ** structure is filled with the currently defined mutex routines.)^
1524 ** This option can be used to overload the default mutex allocation
1525 ** routines with a wrapper used to track mutex usage for performance
1526 ** profiling or testing, for example. ^If SQLite is compiled with
1527 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1528 ** the entire mutexing subsystem is omitted from the build and hence calls to
1529 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1530 ** return [SQLITE_ERROR].</dd>
1531 **
1532 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1533 ** <dd> ^(This option takes two arguments that determine the default
1534 ** memory allocation for the lookaside memory allocator on each
1535 ** [database connection]. The first argument is the
1536 ** size of each lookaside buffer slot and the second is the number of
1537 ** slots allocated to each database connection.)^ ^(This option sets the
1538 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1539 ** verb to [sqlite3_db_config()] can be used to change the lookaside
1540 ** configuration on individual connections.)^ </dd>
1541 **
1542 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1543 ** <dd> ^(This option takes a single argument which is a pointer to
1544 ** an [sqlite3_pcache_methods2] object. This object specifies the interface
1545 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the
1546 ** object and uses it for page cache memory allocations.</dd>
1547 **
1548 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1549 ** <dd> ^(This option takes a single argument which is a pointer to an
1550 ** [sqlite3_pcache_methods2] object. SQLite copies of the current
1551 ** page cache implementation into that object.)^ </dd>
1552 **
1553 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1554 ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1555 ** function with a call signature of void(*)(void*,int,const char*),
1556 ** and a pointer to void. ^If the function pointer is not NULL, it is
1557 ** invoked by [sqlite3_log()] to process each logging event. ^If the
1558 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1559 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1560 ** passed through as the first parameter to the application-defined logger
1561 ** function whenever that function is invoked. ^The second parameter to
1562 ** the logger function is a copy of the first parameter to the corresponding
1563 ** [sqlite3_log()] call and is intended to be a [result code] or an
1564 ** [extended result code]. ^The third parameter passed to the logger is
1565 ** log message after formatting via [sqlite3_snprintf()].
1566 ** The SQLite logging interface is not reentrant; the logger function
1567 ** supplied by the application must not invoke any SQLite interface.
1568 ** In a multi-threaded application, the application-defined logger
1569 ** function must be threadsafe. </dd>
1570 **
1571 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1572 ** <dd> This option takes a single argument of type int. If non-zero, then
1573 ** URI handling is globally enabled. If the parameter is zero, then URI handling
1574 ** is globally disabled. If URI handling is globally enabled, all filenames
1575 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or
1576 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1577 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1578 ** connection is opened. If it is globally disabled, filenames are
1579 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1580 ** database connection is opened. By default, URI handling is globally
1581 ** disabled. The default value may be changed by compiling with the
1582 ** [SQLITE_USE_URI] symbol defined.
1583 **
1584 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1585 ** <dd> This option taks a single integer argument which is interpreted as
1586 ** a boolean in order to enable or disable the use of covering indices for
1587 ** full table scans in the query optimizer. The default setting is determined
1588 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1589 ** if that compile-time option is omitted.
1590 ** The ability to disable the use of covering indices for full table scans
1591 ** is because some incorrectly coded legacy applications might malfunction
1592 ** malfunction when the optimization is enabled. Providing the ability to
1593 ** disable the optimization allows the older, buggy application code to work
1594 ** without change even with newer versions of SQLite.
1595 **
1596 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1597 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1598 ** <dd> These options are obsolete and should not be used by new code.
1599 ** They are retained for backwards compatibility but are now no-ops.
1600 ** </dl>
1601 */
1602 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1603 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1604 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1605 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1606 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1607 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1608 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1609 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1610 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1611 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1612 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1613 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1614 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1615 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
1616 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1617 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1618 #define SQLITE_CONFIG_URI 17 /* int */
1619 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1620 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1621 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1622
1623 /*
1624 ** CAPI3REF: Database Connection Configuration Options
1625 **
1626 ** These constants are the available integer configuration options that
1627 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
1628 **
1629 ** New configuration options may be added in future releases of SQLite.
1630 ** Existing configuration options might be discontinued. Applications
1631 ** should check the return code from [sqlite3_db_config()] to make sure that
1632 ** the call worked. ^The [sqlite3_db_config()] interface will return a
1633 ** non-zero [error code] if a discontinued or unsupported configuration option
1634 ** is invoked.
1635 **
1636 ** <dl>
1637 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1638 ** <dd> ^This option takes three additional arguments that determine the
1639 ** [lookaside memory allocator] configuration for the [database connection].
1640 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1641 ** pointer to a memory buffer to use for lookaside memory.
1642 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1643 ** may be NULL in which case SQLite will allocate the
1644 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1645 ** size of each lookaside buffer slot. ^The third argument is the number of
1646 ** slots. The size of the buffer in the first argument must be greater than
1647 ** or equal to the product of the second and third arguments. The buffer
1648 ** must be aligned to an 8-byte boundary. ^If the second argument to
1649 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1650 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1651 ** configuration for a database connection can only be changed when that
1652 ** connection is not currently using lookaside memory, or in other words
1653 ** when the "current value" returned by
1654 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1655 ** Any attempt to change the lookaside memory configuration when lookaside
1656 ** memory is in use leaves the configuration unchanged and returns
1657 ** [SQLITE_BUSY].)^</dd>
1658 **
1659 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1660 ** <dd> ^This option is used to enable or disable the enforcement of
1661 ** [foreign key constraints]. There should be two additional arguments.
1662 ** The first argument is an integer which is 0 to disable FK enforcement,
1663 ** positive to enable FK enforcement or negative to leave FK enforcement
1664 ** unchanged. The second parameter is a pointer to an integer into which
1665 ** is written 0 or 1 to indicate whether FK enforcement is off or on
1666 ** following this call. The second parameter may be a NULL pointer, in
1667 ** which case the FK enforcement setting is not reported back. </dd>
1668 **
1669 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1670 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1671 ** There should be two additional arguments.
1672 ** The first argument is an integer which is 0 to disable triggers,
1673 ** positive to enable triggers or negative to leave the setting unchanged.
1674 ** The second parameter is a pointer to an integer into which
1675 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
1676 ** following this call. The second parameter may be a NULL pointer, in
1677 ** which case the trigger setting is not reported back. </dd>
1678 **
1679 ** </dl>
1680 */
1681 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1682 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
1683 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
1684
1685
1686 /*
1687 ** CAPI3REF: Enable Or Disable Extended Result Codes
1688 **
1689 ** ^The sqlite3_extended_result_codes() routine enables or disables the
1690 ** [extended result codes] feature of SQLite. ^The extended result
1691 ** codes are disabled by default for historical compatibility.
1692 */
1693 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
1694
1695 /*
1696 ** CAPI3REF: Last Insert Rowid
1697 **
1698 ** ^Each entry in an SQLite table has a unique 64-bit signed
1699 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1700 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1701 ** names are not also used by explicitly declared columns. ^If
1702 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
1703 ** is another alias for the rowid.
1704 **
1705 ** ^This routine returns the [rowid] of the most recent
1706 ** successful [INSERT] into the database from the [database connection]
1707 ** in the first argument. ^As of SQLite version 3.7.7, this routines
1708 ** records the last insert rowid of both ordinary tables and [virtual tables].
1709 ** ^If no successful [INSERT]s
1710 ** have ever occurred on that database connection, zero is returned.
1711 **
1712 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1713 ** method, then this routine will return the [rowid] of the inserted
1714 ** row as long as the trigger or virtual table method is running.
1715 ** But once the trigger or virtual table method ends, the value returned
1716 ** by this routine reverts to what it was before the trigger or virtual
1717 ** table method began.)^
1718 **
1719 ** ^An [INSERT] that fails due to a constraint violation is not a
1720 ** successful [INSERT] and does not change the value returned by this
1721 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
1722 ** and INSERT OR ABORT make no changes to the return value of this
1723 ** routine when their insertion fails. ^(When INSERT OR REPLACE
1724 ** encounters a constraint violation, it does not fail. The
1725 ** INSERT continues to completion after deleting rows that caused
1726 ** the constraint problem so INSERT OR REPLACE will always change
1727 ** the return value of this interface.)^
1728 **
1729 ** ^For the purposes of this routine, an [INSERT] is considered to
1730 ** be successful even if it is subsequently rolled back.
1731 **
1732 ** This function is accessible to SQL statements via the
1733 ** [last_insert_rowid() SQL function].
1734 **
1735 ** If a separate thread performs a new [INSERT] on the same
1736 ** database connection while the [sqlite3_last_insert_rowid()]
1737 ** function is running and thus changes the last insert [rowid],
1738 ** then the value returned by [sqlite3_last_insert_rowid()] is
1739 ** unpredictable and might not equal either the old or the new
1740 ** last insert [rowid].
1741 */
1742 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
1743
1744 /*
1745 ** CAPI3REF: Count The Number Of Rows Modified
1746 **
1747 ** ^This function returns the number of database rows that were changed
1748 ** or inserted or deleted by the most recently completed SQL statement
1749 ** on the [database connection] specified by the first parameter.
1750 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
1751 ** or [DELETE] statement are counted. Auxiliary changes caused by
1752 ** triggers or [foreign key actions] are not counted.)^ Use the
1753 ** [sqlite3_total_changes()] function to find the total number of changes
1754 ** including changes caused by triggers and foreign key actions.
1755 **
1756 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
1757 ** are not counted. Only real table changes are counted.
1758 **
1759 ** ^(A "row change" is a change to a single row of a single table
1760 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that
1761 ** are changed as side effects of [REPLACE] constraint resolution,
1762 ** rollback, ABORT processing, [DROP TABLE], or by any other
1763 ** mechanisms do not count as direct row changes.)^
1764 **
1765 ** A "trigger context" is a scope of execution that begins and
1766 ** ends with the script of a [CREATE TRIGGER | trigger].
1767 ** Most SQL statements are
1768 ** evaluated outside of any trigger. This is the "top level"
1769 ** trigger context. If a trigger fires from the top level, a
1770 ** new trigger context is entered for the duration of that one
1771 ** trigger. Subtriggers create subcontexts for their duration.
1772 **
1773 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
1774 ** not create a new trigger context.
1775 **
1776 ** ^This function returns the number of direct row changes in the
1777 ** most recent INSERT, UPDATE, or DELETE statement within the same
1778 ** trigger context.
1779 **
1780 ** ^Thus, when called from the top level, this function returns the
1781 ** number of changes in the most recent INSERT, UPDATE, or DELETE
1782 ** that also occurred at the top level. ^(Within the body of a trigger,
1783 ** the sqlite3_changes() interface can be called to find the number of
1784 ** changes in the most recently completed INSERT, UPDATE, or DELETE
1785 ** statement within the body of the same trigger.
1786 ** However, the number returned does not include changes
1787 ** caused by subtriggers since those have their own context.)^
1788 **
1789 ** See also the [sqlite3_total_changes()] interface, the
1790 ** [count_changes pragma], and the [changes() SQL function].
1791 **
1792 ** If a separate thread makes changes on the same database connection
1793 ** while [sqlite3_changes()] is running then the value returned
1794 ** is unpredictable and not meaningful.
1795 */
1796 SQLITE_API int sqlite3_changes(sqlite3*);
1797
1798 /*
1799 ** CAPI3REF: Total Number Of Rows Modified
1800 **
1801 ** ^This function returns the number of row changes caused by [INSERT],
1802 ** [UPDATE] or [DELETE] statements since the [database connection] was opened.
1803 ** ^(The count returned by sqlite3_total_changes() includes all changes
1804 ** from all [CREATE TRIGGER | trigger] contexts and changes made by
1805 ** [foreign key actions]. However,
1806 ** the count does not include changes used to implement [REPLACE] constraints,
1807 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The
1808 ** count does not include rows of views that fire an [INSTEAD OF trigger],
1809 ** though if the INSTEAD OF trigger makes changes of its own, those changes
1810 ** are counted.)^
1811 ** ^The sqlite3_total_changes() function counts the changes as soon as
1812 ** the statement that makes them is completed (when the statement handle
1813 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
1814 **
1815 ** See also the [sqlite3_changes()] interface, the
1816 ** [count_changes pragma], and the [total_changes() SQL function].
1817 **
1818 ** If a separate thread makes changes on the same database connection
1819 ** while [sqlite3_total_changes()] is running then the value
1820 ** returned is unpredictable and not meaningful.
1821 */
1822 SQLITE_API int sqlite3_total_changes(sqlite3*);
1823
1824 /*
1825 ** CAPI3REF: Interrupt A Long-Running Query
1826 **
1827 ** ^This function causes any pending database operation to abort and
1828 ** return at its earliest opportunity. This routine is typically
1829 ** called in response to a user action such as pressing "Cancel"
1830 ** or Ctrl-C where the user wants a long query operation to halt
1831 ** immediately.
1832 **
1833 ** ^It is safe to call this routine from a thread different from the
1834 ** thread that is currently running the database operation. But it
1835 ** is not safe to call this routine with a [database connection] that
1836 ** is closed or might close before sqlite3_interrupt() returns.
1837 **
1838 ** ^If an SQL operation is very nearly finished at the time when
1839 ** sqlite3_interrupt() is called, then it might not have an opportunity
1840 ** to be interrupted and might continue to completion.
1841 **
1842 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
1843 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
1844 ** that is inside an explicit transaction, then the entire transaction
1845 ** will be rolled back automatically.
1846 **
1847 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
1848 ** SQL statements on [database connection] D complete. ^Any new SQL statements
1849 ** that are started after the sqlite3_interrupt() call and before the
1850 ** running statements reaches zero are interrupted as if they had been
1851 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
1852 ** that are started after the running statement count reaches zero are
1853 ** not effected by the sqlite3_interrupt().
1854 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
1855 ** SQL statements is a no-op and has no effect on SQL statements
1856 ** that are started after the sqlite3_interrupt() call returns.
1857 **
1858 ** If the database connection closes while [sqlite3_interrupt()]
1859 ** is running then bad things will likely happen.
1860 */
1861 SQLITE_API void sqlite3_interrupt(sqlite3*);
1862
1863 /*
1864 ** CAPI3REF: Determine If An SQL Statement Is Complete
1865 **
1866 ** These routines are useful during command-line input to determine if the
1867 ** currently entered text seems to form a complete SQL statement or
1868 ** if additional input is needed before sending the text into
1869 ** SQLite for parsing. ^These routines return 1 if the input string
1870 ** appears to be a complete SQL statement. ^A statement is judged to be
1871 ** complete if it ends with a semicolon token and is not a prefix of a
1872 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
1873 ** string literals or quoted identifier names or comments are not
1874 ** independent tokens (they are part of the token in which they are
1875 ** embedded) and thus do not count as a statement terminator. ^Whitespace
1876 ** and comments that follow the final semicolon are ignored.
1877 **
1878 ** ^These routines return 0 if the statement is incomplete. ^If a
1879 ** memory allocation fails, then SQLITE_NOMEM is returned.
1880 **
1881 ** ^These routines do not parse the SQL statements thus
1882 ** will not detect syntactically incorrect SQL.
1883 **
1884 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
1885 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
1886 ** automatically by sqlite3_complete16(). If that initialization fails,
1887 ** then the return value from sqlite3_complete16() will be non-zero
1888 ** regardless of whether or not the input SQL is complete.)^
1889 **
1890 ** The input to [sqlite3_complete()] must be a zero-terminated
1891 ** UTF-8 string.
1892 **
1893 ** The input to [sqlite3_complete16()] must be a zero-terminated
1894 ** UTF-16 string in native byte order.
1895 */
1896 SQLITE_API int sqlite3_complete(const char *sql);
1897 SQLITE_API int sqlite3_complete16(const void *sql);
1898
1899 /*
1900 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
1901 **
1902 ** ^This routine sets a callback function that might be invoked whenever
1903 ** an attempt is made to open a database table that another thread
1904 ** or process has locked.
1905 **
1906 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
1907 ** is returned immediately upon encountering the lock. ^If the busy callback
1908 ** is not NULL, then the callback might be invoked with two arguments.
1909 **
1910 ** ^The first argument to the busy handler is a copy of the void* pointer which
1911 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
1912 ** the busy handler callback is the number of times that the busy handler has
1913 ** been invoked for this locking event. ^If the
1914 ** busy callback returns 0, then no additional attempts are made to
1915 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
1916 ** ^If the callback returns non-zero, then another attempt
1917 ** is made to open the database for reading and the cycle repeats.
1918 **
1919 ** The presence of a busy handler does not guarantee that it will be invoked
1920 ** when there is lock contention. ^If SQLite determines that invoking the busy
1921 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
1922 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
1923 ** Consider a scenario where one process is holding a read lock that
1924 ** it is trying to promote to a reserved lock and
1925 ** a second process is holding a reserved lock that it is trying
1926 ** to promote to an exclusive lock. The first process cannot proceed
1927 ** because it is blocked by the second and the second process cannot
1928 ** proceed because it is blocked by the first. If both processes
1929 ** invoke the busy handlers, neither will make any progress. Therefore,
1930 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
1931 ** will induce the first process to release its read lock and allow
1932 ** the second process to proceed.
1933 **
1934 ** ^The default busy callback is NULL.
1935 **
1936 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
1937 ** when SQLite is in the middle of a large transaction where all the
1938 ** changes will not fit into the in-memory cache. SQLite will
1939 ** already hold a RESERVED lock on the database file, but it needs
1940 ** to promote this lock to EXCLUSIVE so that it can spill cache
1941 ** pages into the database file without harm to concurrent
1942 ** readers. ^If it is unable to promote the lock, then the in-memory
1943 ** cache will be left in an inconsistent state and so the error
1944 ** code is promoted from the relatively benign [SQLITE_BUSY] to
1945 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion
1946 ** forces an automatic rollback of the changes. See the
1947 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
1948 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
1949 ** this is important.
1950 **
1951 ** ^(There can only be a single busy handler defined for each
1952 ** [database connection]. Setting a new busy handler clears any
1953 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
1954 ** will also set or clear the busy handler.
1955 **
1956 ** The busy callback should not take any actions which modify the
1957 ** database connection that invoked the busy handler. Any such actions
1958 ** result in undefined behavior.
1959 **
1960 ** A busy handler must not close the database connection
1961 ** or [prepared statement] that invoked the busy handler.
1962 */
1963 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
1964
1965 /*
1966 ** CAPI3REF: Set A Busy Timeout
1967 **
1968 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
1969 ** for a specified amount of time when a table is locked. ^The handler
1970 ** will sleep multiple times until at least "ms" milliseconds of sleeping
1971 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
1972 ** the handler returns 0 which causes [sqlite3_step()] to return
1973 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
1974 **
1975 ** ^Calling this routine with an argument less than or equal to zero
1976 ** turns off all busy handlers.
1977 **
1978 ** ^(There can only be a single busy handler for a particular
1979 ** [database connection] any any given moment. If another busy handler
1980 ** was defined (using [sqlite3_busy_handler()]) prior to calling
1981 ** this routine, that other busy handler is cleared.)^
1982 */
1983 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
1984
1985 /*
1986 ** CAPI3REF: Convenience Routines For Running Queries
1987 **
1988 ** This is a legacy interface that is preserved for backwards compatibility.
1989 ** Use of this interface is not recommended.
1990 **
1991 ** Definition: A <b>result table</b> is memory data structure created by the
1992 ** [sqlite3_get_table()] interface. A result table records the
1993 ** complete query results from one or more queries.
1994 **
1995 ** The table conceptually has a number of rows and columns. But
1996 ** these numbers are not part of the result table itself. These
1997 ** numbers are obtained separately. Let N be the number of rows
1998 ** and M be the number of columns.
1999 **
2000 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2001 ** There are (N+1)*M elements in the array. The first M pointers point
2002 ** to zero-terminated strings that contain the names of the columns.
2003 ** The remaining entries all point to query results. NULL values result
2004 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2005 ** string representation as returned by [sqlite3_column_text()].
2006 **
2007 ** A result table might consist of one or more memory allocations.
2008 ** It is not safe to pass a result table directly to [sqlite3_free()].
2009 ** A result table should be deallocated using [sqlite3_free_table()].
2010 **
2011 ** ^(As an example of the result table format, suppose a query result
2012 ** is as follows:
2013 **
2014 ** <blockquote><pre>
2015 ** Name | Age
2016 ** -----------------------
2017 ** Alice | 43
2018 ** Bob | 28
2019 ** Cindy | 21
2020 ** </pre></blockquote>
2021 **
2022 ** There are two column (M==2) and three rows (N==3). Thus the
2023 ** result table has 8 entries. Suppose the result table is stored
2024 ** in an array names azResult. Then azResult holds this content:
2025 **
2026 ** <blockquote><pre>
2027 ** azResult&#91;0] = "Name";
2028 ** azResult&#91;1] = "Age";
2029 ** azResult&#91;2] = "Alice";
2030 ** azResult&#91;3] = "43";
2031 ** azResult&#91;4] = "Bob";
2032 ** azResult&#91;5] = "28";
2033 ** azResult&#91;6] = "Cindy";
2034 ** azResult&#91;7] = "21";
2035 ** </pre></blockquote>)^
2036 **
2037 ** ^The sqlite3_get_table() function evaluates one or more
2038 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2039 ** string of its 2nd parameter and returns a result table to the
2040 ** pointer given in its 3rd parameter.
2041 **
2042 ** After the application has finished with the result from sqlite3_get_table(),
2043 ** it must pass the result table pointer to sqlite3_free_table() in order to
2044 ** release the memory that was malloced. Because of the way the
2045 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2046 ** function must not try to call [sqlite3_free()] directly. Only
2047 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2048 **
2049 ** The sqlite3_get_table() interface is implemented as a wrapper around
2050 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2051 ** to any internal data structures of SQLite. It uses only the public
2052 ** interface defined here. As a consequence, errors that occur in the
2053 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2054 ** reflected in subsequent calls to [sqlite3_errcode()] or
2055 ** [sqlite3_errmsg()].
2056 */
2057 SQLITE_API int sqlite3_get_table(
2058 sqlite3 *db, /* An open database */
2059 const char *zSql, /* SQL to be evaluated */
2060 char ***pazResult, /* Results of the query */
2061 int *pnRow, /* Number of result rows written here */
2062 int *pnColumn, /* Number of result columns written here */
2063 char **pzErrmsg /* Error msg written here */
2064 );
2065 SQLITE_API void sqlite3_free_table(char **result);
2066
2067 /*
2068 ** CAPI3REF: Formatted String Printing Functions
2069 **
2070 ** These routines are work-alikes of the "printf()" family of functions
2071 ** from the standard C library.
2072 **
2073 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2074 ** results into memory obtained from [sqlite3_malloc()].
2075 ** The strings returned by these two routines should be
2076 ** released by [sqlite3_free()]. ^Both routines return a
2077 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2078 ** memory to hold the resulting string.
2079 **
2080 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2081 ** the standard C library. The result is written into the
2082 ** buffer supplied as the second parameter whose size is given by
2083 ** the first parameter. Note that the order of the
2084 ** first two parameters is reversed from snprintf().)^ This is an
2085 ** historical accident that cannot be fixed without breaking
2086 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2087 ** returns a pointer to its buffer instead of the number of
2088 ** characters actually written into the buffer.)^ We admit that
2089 ** the number of characters written would be a more useful return
2090 ** value but we cannot change the implementation of sqlite3_snprintf()
2091 ** now without breaking compatibility.
2092 **
2093 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2094 ** guarantees that the buffer is always zero-terminated. ^The first
2095 ** parameter "n" is the total size of the buffer, including space for
2096 ** the zero terminator. So the longest string that can be completely
2097 ** written will be n-1 characters.
2098 **
2099 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2100 **
2101 ** These routines all implement some additional formatting
2102 ** options that are useful for constructing SQL statements.
2103 ** All of the usual printf() formatting options apply. In addition, there
2104 ** is are "%q", "%Q", and "%z" options.
2105 **
2106 ** ^(The %q option works like %s in that it substitutes a nul-terminated
2107 ** string from the argument list. But %q also doubles every '\'' character.
2108 ** %q is designed for use inside a string literal.)^ By doubling each '\''
2109 ** character it escapes that character and allows it to be inserted into
2110 ** the string.
2111 **
2112 ** For example, assume the string variable zText contains text as follows:
2113 **
2114 ** <blockquote><pre>
2115 ** char *zText = "It's a happy day!";
2116 ** </pre></blockquote>
2117 **
2118 ** One can use this text in an SQL statement as follows:
2119 **
2120 ** <blockquote><pre>
2121 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2122 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2123 ** sqlite3_free(zSQL);
2124 ** </pre></blockquote>
2125 **
2126 ** Because the %q format string is used, the '\'' character in zText
2127 ** is escaped and the SQL generated is as follows:
2128 **
2129 ** <blockquote><pre>
2130 ** INSERT INTO table1 VALUES('It''s a happy day!')
2131 ** </pre></blockquote>
2132 **
2133 ** This is correct. Had we used %s instead of %q, the generated SQL
2134 ** would have looked like this:
2135 **
2136 ** <blockquote><pre>
2137 ** INSERT INTO table1 VALUES('It's a happy day!');
2138 ** </pre></blockquote>
2139 **
2140 ** This second example is an SQL syntax error. As a general rule you should
2141 ** always use %q instead of %s when inserting text into a string literal.
2142 **
2143 ** ^(The %Q option works like %q except it also adds single quotes around
2144 ** the outside of the total string. Additionally, if the parameter in the
2145 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2146 ** single quotes).)^ So, for example, one could say:
2147 **
2148 ** <blockquote><pre>
2149 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2150 ** sqlite3_exec(db, zSQL, 0, 0, 0);
2151 ** sqlite3_free(zSQL);
2152 ** </pre></blockquote>
2153 **
2154 ** The code above will render a correct SQL statement in the zSQL
2155 ** variable even if the zText variable is a NULL pointer.
2156 **
2157 ** ^(The "%z" formatting option works like "%s" but with the
2158 ** addition that after the string has been read and copied into
2159 ** the result, [sqlite3_free()] is called on the input string.)^
2160 */
2161 SQLITE_API char *sqlite3_mprintf(const char*,...);
2162 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2163 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2164 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2165
2166 /*
2167 ** CAPI3REF: Memory Allocation Subsystem
2168 **
2169 ** The SQLite core uses these three routines for all of its own
2170 ** internal memory allocation needs. "Core" in the previous sentence
2171 ** does not include operating-system specific VFS implementation. The
2172 ** Windows VFS uses native malloc() and free() for some operations.
2173 **
2174 ** ^The sqlite3_malloc() routine returns a pointer to a block
2175 ** of memory at least N bytes in length, where N is the parameter.
2176 ** ^If sqlite3_malloc() is unable to obtain sufficient free
2177 ** memory, it returns a NULL pointer. ^If the parameter N to
2178 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2179 ** a NULL pointer.
2180 **
2181 ** ^Calling sqlite3_free() with a pointer previously returned
2182 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2183 ** that it might be reused. ^The sqlite3_free() routine is
2184 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
2185 ** to sqlite3_free() is harmless. After being freed, memory
2186 ** should neither be read nor written. Even reading previously freed
2187 ** memory might result in a segmentation fault or other severe error.
2188 ** Memory corruption, a segmentation fault, or other severe error
2189 ** might result if sqlite3_free() is called with a non-NULL pointer that
2190 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2191 **
2192 ** ^(The sqlite3_realloc() interface attempts to resize a
2193 ** prior memory allocation to be at least N bytes, where N is the
2194 ** second parameter. The memory allocation to be resized is the first
2195 ** parameter.)^ ^ If the first parameter to sqlite3_realloc()
2196 ** is a NULL pointer then its behavior is identical to calling
2197 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
2198 ** ^If the second parameter to sqlite3_realloc() is zero or
2199 ** negative then the behavior is exactly the same as calling
2200 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
2201 ** ^sqlite3_realloc() returns a pointer to a memory allocation
2202 ** of at least N bytes in size or NULL if sufficient memory is unavailable.
2203 ** ^If M is the size of the prior allocation, then min(N,M) bytes
2204 ** of the prior allocation are copied into the beginning of buffer returned
2205 ** by sqlite3_realloc() and the prior allocation is freed.
2206 ** ^If sqlite3_realloc() returns NULL, then the prior allocation
2207 ** is not freed.
2208 **
2209 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
2210 ** is always aligned to at least an 8 byte boundary, or to a
2211 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2212 ** option is used.
2213 **
2214 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2215 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2216 ** implementation of these routines to be omitted. That capability
2217 ** is no longer provided. Only built-in memory allocators can be used.
2218 **
2219 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2220 ** the system malloc() and free() directly when converting
2221 ** filenames between the UTF-8 encoding used by SQLite
2222 ** and whatever filename encoding is used by the particular Windows
2223 ** installation. Memory allocation errors were detected, but
2224 ** they were reported back as [SQLITE_CANTOPEN] or
2225 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2226 **
2227 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2228 ** must be either NULL or else pointers obtained from a prior
2229 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2230 ** not yet been released.
2231 **
2232 ** The application must not read or write any part of
2233 ** a block of memory after it has been released using
2234 ** [sqlite3_free()] or [sqlite3_realloc()].
2235 */
2236 SQLITE_API void *sqlite3_malloc(int);
2237 SQLITE_API void *sqlite3_realloc(void*, int);
2238 SQLITE_API void sqlite3_free(void*);
2239
2240 /*
2241 ** CAPI3REF: Memory Allocator Statistics
2242 **
2243 ** SQLite provides these two interfaces for reporting on the status
2244 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2245 ** routines, which form the built-in memory allocation subsystem.
2246 **
2247 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
2248 ** of memory currently outstanding (malloced but not freed).
2249 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
2250 ** value of [sqlite3_memory_used()] since the high-water mark
2251 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
2252 ** [sqlite3_memory_highwater()] include any overhead
2253 ** added by SQLite in its implementation of [sqlite3_malloc()],
2254 ** but not overhead added by the any underlying system library
2255 ** routines that [sqlite3_malloc()] may call.
2256 **
2257 ** ^The memory high-water mark is reset to the current value of
2258 ** [sqlite3_memory_used()] if and only if the parameter to
2259 ** [sqlite3_memory_highwater()] is true. ^The value returned
2260 ** by [sqlite3_memory_highwater(1)] is the high-water mark
2261 ** prior to the reset.
2262 */
2263 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2264 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2265
2266 /*
2267 ** CAPI3REF: Pseudo-Random Number Generator
2268 **
2269 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2270 ** select random [ROWID | ROWIDs] when inserting new records into a table that
2271 ** already uses the largest possible [ROWID]. The PRNG is also used for
2272 ** the build-in random() and randomblob() SQL functions. This interface allows
2273 ** applications to access the same PRNG for other purposes.
2274 **
2275 ** ^A call to this routine stores N bytes of randomness into buffer P.
2276 **
2277 ** ^The first time this routine is invoked (either internally or by
2278 ** the application) the PRNG is seeded using randomness obtained
2279 ** from the xRandomness method of the default [sqlite3_vfs] object.
2280 ** ^On all subsequent invocations, the pseudo-randomness is generated
2281 ** internally and without recourse to the [sqlite3_vfs] xRandomness
2282 ** method.
2283 */
2284 SQLITE_API void sqlite3_randomness(int N, void *P);
2285
2286 /*
2287 ** CAPI3REF: Compile-Time Authorization Callbacks
2288 **
2289 ** ^This routine registers an authorizer callback with a particular
2290 ** [database connection], supplied in the first argument.
2291 ** ^The authorizer callback is invoked as SQL statements are being compiled
2292 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2293 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2294 ** points during the compilation process, as logic is being created
2295 ** to perform various actions, the authorizer callback is invoked to
2296 ** see if those actions are allowed. ^The authorizer callback should
2297 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2298 ** specific action but allow the SQL statement to continue to be
2299 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2300 ** rejected with an error. ^If the authorizer callback returns
2301 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2302 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2303 ** the authorizer will fail with an error message.
2304 **
2305 ** When the callback returns [SQLITE_OK], that means the operation
2306 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
2307 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
2308 ** authorizer will fail with an error message explaining that
2309 ** access is denied.
2310 **
2311 ** ^The first parameter to the authorizer callback is a copy of the third
2312 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2313 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
2314 ** the particular action to be authorized. ^The third through sixth parameters
2315 ** to the callback are zero-terminated strings that contain additional
2316 ** details about the action to be authorized.
2317 **
2318 ** ^If the action code is [SQLITE_READ]
2319 ** and the callback returns [SQLITE_IGNORE] then the
2320 ** [prepared statement] statement is constructed to substitute
2321 ** a NULL value in place of the table column that would have
2322 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2323 ** return can be used to deny an untrusted user access to individual
2324 ** columns of a table.
2325 ** ^If the action code is [SQLITE_DELETE] and the callback returns
2326 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2327 ** [truncate optimization] is disabled and all rows are deleted individually.
2328 **
2329 ** An authorizer is used when [sqlite3_prepare | preparing]
2330 ** SQL statements from an untrusted source, to ensure that the SQL statements
2331 ** do not try to access data they are not allowed to see, or that they do not
2332 ** try to execute malicious statements that damage the database. For
2333 ** example, an application may allow a user to enter arbitrary
2334 ** SQL queries for evaluation by a database. But the application does
2335 ** not want the user to be able to make arbitrary changes to the
2336 ** database. An authorizer could then be put in place while the
2337 ** user-entered SQL is being [sqlite3_prepare | prepared] that
2338 ** disallows everything except [SELECT] statements.
2339 **
2340 ** Applications that need to process SQL from untrusted sources
2341 ** might also consider lowering resource limits using [sqlite3_limit()]
2342 ** and limiting database size using the [max_page_count] [PRAGMA]
2343 ** in addition to using an authorizer.
2344 **
2345 ** ^(Only a single authorizer can be in place on a database connection
2346 ** at a time. Each call to sqlite3_set_authorizer overrides the
2347 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2348 ** The authorizer is disabled by default.
2349 **
2350 ** The authorizer callback must not do anything that will modify
2351 ** the database connection that invoked the authorizer callback.
2352 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2353 ** database connections for the meaning of "modify" in this paragraph.
2354 **
2355 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2356 ** statement might be re-prepared during [sqlite3_step()] due to a
2357 ** schema change. Hence, the application should ensure that the
2358 ** correct authorizer callback remains in place during the [sqlite3_step()].
2359 **
2360 ** ^Note that the authorizer callback is invoked only during
2361 ** [sqlite3_prepare()] or its variants. Authorization is not
2362 ** performed during statement evaluation in [sqlite3_step()], unless
2363 ** as stated in the previous paragraph, sqlite3_step() invokes
2364 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2365 */
2366 SQLITE_API int sqlite3_set_authorizer(
2367 sqlite3*,
2368 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2369 void *pUserData
2370 );
2371
2372 /*
2373 ** CAPI3REF: Authorizer Return Codes
2374 **
2375 ** The [sqlite3_set_authorizer | authorizer callback function] must
2376 ** return either [SQLITE_OK] or one of these two constants in order
2377 ** to signal SQLite whether or not the action is permitted. See the
2378 ** [sqlite3_set_authorizer | authorizer documentation] for additional
2379 ** information.
2380 **
2381 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code]
2382 ** from the [sqlite3_vtab_on_conflict()] interface.
2383 */
2384 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2385 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2386
2387 /*
2388 ** CAPI3REF: Authorizer Action Codes
2389 **
2390 ** The [sqlite3_set_authorizer()] interface registers a callback function
2391 ** that is invoked to authorize certain SQL statement actions. The
2392 ** second parameter to the callback is an integer code that specifies
2393 ** what action is being authorized. These are the integer action codes that
2394 ** the authorizer callback may be passed.
2395 **
2396 ** These action code values signify what kind of operation is to be
2397 ** authorized. The 3rd and 4th parameters to the authorization
2398 ** callback function will be parameters or NULL depending on which of these
2399 ** codes is used as the second parameter. ^(The 5th parameter to the
2400 ** authorizer callback is the name of the database ("main", "temp",
2401 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2402 ** is the name of the inner-most trigger or view that is responsible for
2403 ** the access attempt or NULL if this access attempt is directly from
2404 ** top-level SQL code.
2405 */
2406 /******************************************* 3rd ************ 4th ***********/
2407 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2408 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2409 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2410 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2411 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2412 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2413 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2414 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2415 #define SQLITE_DELETE 9 /* Table Name NULL */
2416 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2417 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2418 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2419 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2420 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2421 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2422 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2423 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
2424 #define SQLITE_INSERT 18 /* Table Name NULL */
2425 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2426 #define SQLITE_READ 20 /* Table Name Column Name */
2427 #define SQLITE_SELECT 21 /* NULL NULL */
2428 #define SQLITE_TRANSACTION 22 /* Operation NULL */
2429 #define SQLITE_UPDATE 23 /* Table Name Column Name */
2430 #define SQLITE_ATTACH 24 /* Filename NULL */
2431 #define SQLITE_DETACH 25 /* Database Name NULL */
2432 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2433 #define SQLITE_REINDEX 27 /* Index Name NULL */
2434 #define SQLITE_ANALYZE 28 /* Table Name NULL */
2435 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2436 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2437 #define SQLITE_FUNCTION 31 /* NULL Function Name */
2438 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2439 #define SQLITE_COPY 0 /* No longer used */
2440
2441 /*
2442 ** CAPI3REF: Tracing And Profiling Functions
2443 **
2444 ** These routines register callback functions that can be used for
2445 ** tracing and profiling the execution of SQL statements.
2446 **
2447 ** ^The callback function registered by sqlite3_trace() is invoked at
2448 ** various times when an SQL statement is being run by [sqlite3_step()].
2449 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2450 ** SQL statement text as the statement first begins executing.
2451 ** ^(Additional sqlite3_trace() callbacks might occur
2452 ** as each triggered subprogram is entered. The callbacks for triggers
2453 ** contain a UTF-8 SQL comment that identifies the trigger.)^
2454 **
2455 ** ^The callback function registered by sqlite3_profile() is invoked
2456 ** as each SQL statement finishes. ^The profile callback contains
2457 ** the original statement text and an estimate of wall-clock time
2458 ** of how long that statement took to run. ^The profile callback
2459 ** time is in units of nanoseconds, however the current implementation
2460 ** is only capable of millisecond resolution so the six least significant
2461 ** digits in the time are meaningless. Future versions of SQLite
2462 ** might provide greater resolution on the profiler callback. The
2463 ** sqlite3_profile() function is considered experimental and is
2464 ** subject to change in future versions of SQLite.
2465 */
2466 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2467 SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
2468 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2469
2470 /*
2471 ** CAPI3REF: Query Progress Callbacks
2472 **
2473 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2474 ** function X to be invoked periodically during long running calls to
2475 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2476 ** database connection D. An example use for this
2477 ** interface is to keep a GUI updated during a large query.
2478 **
2479 ** ^The parameter P is passed through as the only parameter to the
2480 ** callback function X. ^The parameter N is the number of
2481 ** [virtual machine instructions] that are evaluated between successive
2482 ** invocations of the callback X.
2483 **
2484 ** ^Only a single progress handler may be defined at one time per
2485 ** [database connection]; setting a new progress handler cancels the
2486 ** old one. ^Setting parameter X to NULL disables the progress handler.
2487 ** ^The progress handler is also disabled by setting N to a value less
2488 ** than 1.
2489 **
2490 ** ^If the progress callback returns non-zero, the operation is
2491 ** interrupted. This feature can be used to implement a
2492 ** "Cancel" button on a GUI progress dialog box.
2493 **
2494 ** The progress handler callback must not do anything that will modify
2495 ** the database connection that invoked the progress handler.
2496 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2497 ** database connections for the meaning of "modify" in this paragraph.
2498 **
2499 */
2500 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2501
2502 /*
2503 ** CAPI3REF: Opening A New Database Connection
2504 **
2505 ** ^These routines open an SQLite database file as specified by the
2506 ** filename argument. ^The filename argument is interpreted as UTF-8 for
2507 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2508 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
2509 ** returned in *ppDb, even if an error occurs. The only exception is that
2510 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2511 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2512 ** object.)^ ^(If the database is opened (and/or created) successfully, then
2513 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2514 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2515 ** an English language description of the error following a failure of any
2516 ** of the sqlite3_open() routines.
2517 **
2518 ** ^The default encoding for the database will be UTF-8 if
2519 ** sqlite3_open() or sqlite3_open_v2() is called and
2520 ** UTF-16 in the native byte order if sqlite3_open16() is used.
2521 **
2522 ** Whether or not an error occurs when it is opened, resources
2523 ** associated with the [database connection] handle should be released by
2524 ** passing it to [sqlite3_close()] when it is no longer required.
2525 **
2526 ** The sqlite3_open_v2() interface works like sqlite3_open()
2527 ** except that it accepts two additional parameters for additional control
2528 ** over the new database connection. ^(The flags parameter to
2529 ** sqlite3_open_v2() can take one of
2530 ** the following three values, optionally combined with the
2531 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2532 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2533 **
2534 ** <dl>
2535 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2536 ** <dd>The database is opened in read-only mode. If the database does not
2537 ** already exist, an error is returned.</dd>)^
2538 **
2539 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2540 ** <dd>The database is opened for reading and writing if possible, or reading
2541 ** only if the file is write protected by the operating system. In either
2542 ** case the database must already exist, otherwise an error is returned.</dd>)^
2543 **
2544 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2545 ** <dd>The database is opened for reading and writing, and is created if
2546 ** it does not already exist. This is the behavior that is always used for
2547 ** sqlite3_open() and sqlite3_open16().</dd>)^
2548 ** </dl>
2549 **
2550 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
2551 ** combinations shown above optionally combined with other
2552 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2553 ** then the behavior is undefined.
2554 **
2555 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2556 ** opens in the multi-thread [threading mode] as long as the single-thread
2557 ** mode has not been set at compile-time or start-time. ^If the
2558 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2559 ** in the serialized [threading mode] unless single-thread was
2560 ** previously selected at compile-time or start-time.
2561 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2562 ** eligible to use [shared cache mode], regardless of whether or not shared
2563 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
2564 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2565 ** participate in [shared cache mode] even if it is enabled.
2566 **
2567 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
2568 ** [sqlite3_vfs] object that defines the operating system interface that
2569 ** the new database connection should use. ^If the fourth parameter is
2570 ** a NULL pointer then the default [sqlite3_vfs] object is used.
2571 **
2572 ** ^If the filename is ":memory:", then a private, temporary in-memory database
2573 ** is created for the connection. ^This in-memory database will vanish when
2574 ** the database connection is closed. Future versions of SQLite might
2575 ** make use of additional special filenames that begin with the ":" character.
2576 ** It is recommended that when a database filename actually does begin with
2577 ** a ":" character you should prefix the filename with a pathname such as
2578 ** "./" to avoid ambiguity.
2579 **
2580 ** ^If the filename is an empty string, then a private, temporary
2581 ** on-disk database will be created. ^This private database will be
2582 ** automatically deleted as soon as the database connection is closed.
2583 **
2584 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2585 **
2586 ** ^If [URI filename] interpretation is enabled, and the filename argument
2587 ** begins with "file:", then the filename is interpreted as a URI. ^URI
2588 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2589 ** set in the fourth argument to sqlite3_open_v2(), or if it has
2590 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2591 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2592 ** As of SQLite version 3.7.7, URI filename interpretation is turned off
2593 ** by default, but future releases of SQLite might enable URI filename
2594 ** interpretation by default. See "[URI filenames]" for additional
2595 ** information.
2596 **
2597 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2598 ** authority, then it must be either an empty string or the string
2599 ** "localhost". ^If the authority is not an empty string or "localhost", an
2600 ** error is returned to the caller. ^The fragment component of a URI, if
2601 ** present, is ignored.
2602 **
2603 ** ^SQLite uses the path component of the URI as the name of the disk file
2604 ** which contains the database. ^If the path begins with a '/' character,
2605 ** then it is interpreted as an absolute path. ^If the path does not begin
2606 ** with a '/' (meaning that the authority section is omitted from the URI)
2607 ** then the path is interpreted as a relative path.
2608 ** ^On windows, the first component of an absolute path
2609 ** is a drive specification (e.g. "C:").
2610 **
2611 ** [[core URI query parameters]]
2612 ** The query component of a URI may contain parameters that are interpreted
2613 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
2614 ** SQLite interprets the following three query parameters:
2615 **
2616 ** <ul>
2617 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2618 ** a VFS object that provides the operating system interface that should
2619 ** be used to access the database file on disk. ^If this option is set to
2620 ** an empty string the default VFS object is used. ^Specifying an unknown
2621 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2622 ** present, then the VFS specified by the option takes precedence over
2623 ** the value passed as the fourth parameter to sqlite3_open_v2().
2624 **
2625 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
2626 ** "rwc", or "memory". Attempting to set it to any other value is
2627 ** an error)^.
2628 ** ^If "ro" is specified, then the database is opened for read-only
2629 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2630 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
2631 ** "rw", then the database is opened for read-write (but not create)
2632 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2633 ** been set. ^Value "rwc" is equivalent to setting both
2634 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
2635 ** set to "memory" then a pure [in-memory database] that never reads
2636 ** or writes from disk is used. ^It is an error to specify a value for
2637 ** the mode parameter that is less restrictive than that specified by
2638 ** the flags passed in the third parameter to sqlite3_open_v2().
2639 **
2640 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2641 ** "private". ^Setting it to "shared" is equivalent to setting the
2642 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2643 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2644 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2645 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2646 ** a URI filename, its value overrides any behaviour requested by setting
2647 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2648 ** </ul>
2649 **
2650 ** ^Specifying an unknown parameter in the query component of a URI is not an
2651 ** error. Future versions of SQLite might understand additional query
2652 ** parameters. See "[query parameters with special meaning to SQLite]" for
2653 ** additional information.
2654 **
2655 ** [[URI filename examples]] <h3>URI filename examples</h3>
2656 **
2657 ** <table border="1" align=center cellpadding=5>
2658 ** <tr><th> URI filenames <th> Results
2659 ** <tr><td> file:data.db <td>
2660 ** Open the file "data.db" in the current directory.
2661 ** <tr><td> file:/home/fred/data.db<br>
2662 ** file:///home/fred/data.db <br>
2663 ** file://localhost/home/fred/data.db <br> <td>
2664 ** Open the database file "/home/fred/data.db".
2665 ** <tr><td> file://darkstar/home/fred/data.db <td>
2666 ** An error. "darkstar" is not a recognized authority.
2667 ** <tr><td style="white-space:nowrap">
2668 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
2669 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
2670 ** C:. Note that the %20 escaping in this example is not strictly
2671 ** necessary - space characters can be used literally
2672 ** in URI filenames.
2673 ** <tr><td> file:data.db?mode=ro&cache=private <td>
2674 ** Open file "data.db" in the current directory for read-only access.
2675 ** Regardless of whether or not shared-cache mode is enabled by
2676 ** default, use a private cache.
2677 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td>
2678 ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock".
2679 ** <tr><td> file:data.db?mode=readonly <td>
2680 ** An error. "readonly" is not a valid option for the "mode" parameter.
2681 ** </table>
2682 **
2683 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
2684 ** query components of a URI. A hexadecimal escape sequence consists of a
2685 ** percent sign - "%" - followed by exactly two hexadecimal digits
2686 ** specifying an octet value. ^Before the path or query components of a
2687 ** URI filename are interpreted, they are encoded using UTF-8 and all
2688 ** hexadecimal escape sequences replaced by a single byte containing the
2689 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
2690 ** the results are undefined.
2691 **
2692 ** <b>Note to Windows users:</b> The encoding used for the filename argument
2693 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
2694 ** codepage is currently defined. Filenames containing international
2695 ** characters must be converted to UTF-8 prior to passing them into
2696 ** sqlite3_open() or sqlite3_open_v2().
2697 **
2698 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
2699 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
2700 ** features that require the use of temporary files may fail.
2701 **
2702 ** See also: [sqlite3_temp_directory]
2703 */
2704 SQLITE_API int sqlite3_open(
2705 const char *filename, /* Database filename (UTF-8) */
2706 sqlite3 **ppDb /* OUT: SQLite db handle */
2707 );
2708 SQLITE_API int sqlite3_open16(
2709 const void *filename, /* Database filename (UTF-16) */
2710 sqlite3 **ppDb /* OUT: SQLite db handle */
2711 );
2712 SQLITE_API int sqlite3_open_v2(
2713 const char *filename, /* Database filename (UTF-8) */
2714 sqlite3 **ppDb, /* OUT: SQLite db handle */
2715 int flags, /* Flags */
2716 const char *zVfs /* Name of VFS module to use */
2717 );
2718
2719 /*
2720 ** CAPI3REF: Obtain Values For URI Parameters
2721 **
2722 ** These are utility routines, useful to VFS implementations, that check
2723 ** to see if a database file was a URI that contained a specific query
2724 ** parameter, and if so obtains the value of that query parameter.
2725 **
2726 ** If F is the database filename pointer passed into the xOpen() method of
2727 ** a VFS implementation when the flags parameter to xOpen() has one or
2728 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
2729 ** P is the name of the query parameter, then
2730 ** sqlite3_uri_parameter(F,P) returns the value of the P
2731 ** parameter if it exists or a NULL pointer if P does not appear as a
2732 ** query parameter on F. If P is a query parameter of F
2733 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
2734 ** a pointer to an empty string.
2735 **
2736 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
2737 ** parameter and returns true (1) or false (0) according to the value
2738 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
2739 ** value of query parameter P is one of "yes", "true", or "on" in any
2740 ** case or if the value begins with a non-zero number. The
2741 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
2742 ** query parameter P is one of "no", "false", or "off" in any case or
2743 ** if the value begins with a numeric zero. If P is not a query
2744 ** parameter on F or if the value of P is does not match any of the
2745 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
2746 **
2747 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
2748 ** 64-bit signed integer and returns that integer, or D if P does not
2749 ** exist. If the value of P is something other than an integer, then
2750 ** zero is returned.
2751 **
2752 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
2753 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
2754 ** is not a database file pathname pointer that SQLite passed into the xOpen
2755 ** VFS method, then the behavior of this routine is undefined and probably
2756 ** undesirable.
2757 */
2758 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
2759 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
2760 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
2761
2762
2763 /*
2764 ** CAPI3REF: Error Codes And Messages
2765 **
2766 ** ^The sqlite3_errcode() interface returns the numeric [result code] or
2767 ** [extended result code] for the most recent failed sqlite3_* API call
2768 ** associated with a [database connection]. If a prior API call failed
2769 ** but the most recent API call succeeded, the return value from
2770 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode()
2771 ** interface is the same except that it always returns the
2772 ** [extended result code] even when extended result codes are
2773 ** disabled.
2774 **
2775 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
2776 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
2777 ** ^(Memory to hold the error message string is managed internally.
2778 ** The application does not need to worry about freeing the result.
2779 ** However, the error string might be overwritten or deallocated by
2780 ** subsequent calls to other SQLite interface functions.)^
2781 **
2782 ** ^The sqlite3_errstr() interface returns the English-language text
2783 ** that describes the [result code], as UTF-8.
2784 ** ^(Memory to hold the error message string is managed internally
2785 ** and must not be freed by the application)^.
2786 **
2787 ** When the serialized [threading mode] is in use, it might be the
2788 ** case that a second error occurs on a separate thread in between
2789 ** the time of the first error and the call to these interfaces.
2790 ** When that happens, the second error will be reported since these
2791 ** interfaces always report the most recent result. To avoid
2792 ** this, each thread can obtain exclusive use of the [database connection] D
2793 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
2794 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
2795 ** all calls to the interfaces listed here are completed.
2796 **
2797 ** If an interface fails with SQLITE_MISUSE, that means the interface
2798 ** was invoked incorrectly by the application. In that case, the
2799 ** error code and message may or may not be set.
2800 */
2801 SQLITE_API int sqlite3_errcode(sqlite3 *db);
2802 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
2803 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
2804 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
2805 SQLITE_API const char *sqlite3_errstr(int);
2806
2807 /*
2808 ** CAPI3REF: SQL Statement Object
2809 ** KEYWORDS: {prepared statement} {prepared statements}
2810 **
2811 ** An instance of this object represents a single SQL statement.
2812 ** This object is variously known as a "prepared statement" or a
2813 ** "compiled SQL statement" or simply as a "statement".
2814 **
2815 ** The life of a statement object goes something like this:
2816 **
2817 ** <ol>
2818 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
2819 ** function.
2820 ** <li> Bind values to [host parameters] using the sqlite3_bind_*()
2821 ** interfaces.
2822 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
2823 ** <li> Reset the statement using [sqlite3_reset()] then go back
2824 ** to step 2. Do this zero or more times.
2825 ** <li> Destroy the object using [sqlite3_finalize()].
2826 ** </ol>
2827 **
2828 ** Refer to documentation on individual methods above for additional
2829 ** information.
2830 */
2831 typedef struct sqlite3_stmt sqlite3_stmt;
2832
2833 /*
2834 ** CAPI3REF: Run-time Limits
2835 **
2836 ** ^(This interface allows the size of various constructs to be limited
2837 ** on a connection by connection basis. The first parameter is the
2838 ** [database connection] whose limit is to be set or queried. The
2839 ** second parameter is one of the [limit categories] that define a
2840 ** class of constructs to be size limited. The third parameter is the
2841 ** new limit for that construct.)^
2842 **
2843 ** ^If the new limit is a negative number, the limit is unchanged.
2844 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
2845 ** [limits | hard upper bound]
2846 ** set at compile-time by a C preprocessor macro called
2847 ** [limits | SQLITE_MAX_<i>NAME</i>].
2848 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
2849 ** ^Attempts to increase a limit above its hard upper bound are
2850 ** silently truncated to the hard upper bound.
2851 **
2852 ** ^Regardless of whether or not the limit was changed, the
2853 ** [sqlite3_limit()] interface returns the prior value of the limit.
2854 ** ^Hence, to find the current value of a limit without changing it,
2855 ** simply invoke this interface with the third parameter set to -1.
2856 **
2857 ** Run-time limits are intended for use in applications that manage
2858 ** both their own internal database and also databases that are controlled
2859 ** by untrusted external sources. An example application might be a
2860 ** web browser that has its own databases for storing history and
2861 ** separate databases controlled by JavaScript applications downloaded
2862 ** off the Internet. The internal databases can be given the
2863 ** large, default limits. Databases managed by external sources can
2864 ** be given much smaller limits designed to prevent a denial of service
2865 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
2866 ** interface to further control untrusted SQL. The size of the database
2867 ** created by an untrusted script can be contained using the
2868 ** [max_page_count] [PRAGMA].
2869 **
2870 ** New run-time limit categories may be added in future releases.
2871 */
2872 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
2873
2874 /*
2875 ** CAPI3REF: Run-Time Limit Categories
2876 ** KEYWORDS: {limit category} {*limit categories}
2877 **
2878 ** These constants define various performance limits
2879 ** that can be lowered at run-time using [sqlite3_limit()].
2880 ** The synopsis of the meanings of the various limits is shown below.
2881 ** Additional information is available at [limits | Limits in SQLite].
2882 **
2883 ** <dl>
2884 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
2885 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
2886 **
2887 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
2888 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
2889 **
2890 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
2891 ** <dd>The maximum number of columns in a table definition or in the
2892 ** result set of a [SELECT] or the maximum number of columns in an index
2893 ** or in an ORDER BY or GROUP BY clause.</dd>)^
2894 **
2895 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
2896 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
2897 **
2898 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
2899 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
2900 **
2901 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
2902 ** <dd>The maximum number of instructions in a virtual machine program
2903 ** used to implement an SQL statement. This limit is not currently
2904 ** enforced, though that might be added in some future release of
2905 ** SQLite.</dd>)^
2906 **
2907 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
2908 ** <dd>The maximum number of arguments on a function.</dd>)^
2909 **
2910 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
2911 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
2912 **
2913 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
2914 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
2915 ** <dd>The maximum length of the pattern argument to the [LIKE] or
2916 ** [GLOB] operators.</dd>)^
2917 **
2918 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
2919 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
2920 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
2921 **
2922 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
2923 ** <dd>The maximum depth of recursion for triggers.</dd>)^
2924 ** </dl>
2925 */
2926 #define SQLITE_LIMIT_LENGTH 0
2927 #define SQLITE_LIMIT_SQL_LENGTH 1
2928 #define SQLITE_LIMIT_COLUMN 2
2929 #define SQLITE_LIMIT_EXPR_DEPTH 3
2930 #define SQLITE_LIMIT_COMPOUND_SELECT 4
2931 #define SQLITE_LIMIT_VDBE_OP 5
2932 #define SQLITE_LIMIT_FUNCTION_ARG 6
2933 #define SQLITE_LIMIT_ATTACHED 7
2934 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
2935 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
2936 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
2937
2938 /*
2939 ** CAPI3REF: Compiling An SQL Statement
2940 ** KEYWORDS: {SQL statement compiler}
2941 **
2942 ** To execute an SQL query, it must first be compiled into a byte-code
2943 ** program using one of these routines.
2944 **
2945 ** The first argument, "db", is a [database connection] obtained from a
2946 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
2947 ** [sqlite3_open16()]. The database connection must not have been closed.
2948 **
2949 ** The second argument, "zSql", is the statement to be compiled, encoded
2950 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
2951 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
2952 ** use UTF-16.
2953 **
2954 ** ^If the nByte argument is less than zero, then zSql is read up to the
2955 ** first zero terminator. ^If nByte is non-negative, then it is the maximum
2956 ** number of bytes read from zSql. ^When nByte is non-negative, the
2957 ** zSql string ends at either the first '\000' or '\u0000' character or
2958 ** the nByte-th byte, whichever comes first. If the caller knows
2959 ** that the supplied string is nul-terminated, then there is a small
2960 ** performance advantage to be gained by passing an nByte parameter that
2961 ** is equal to the number of bytes in the input string <i>including</i>
2962 ** the nul-terminator bytes as this saves SQLite from having to
2963 ** make a copy of the input string.
2964 **
2965 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
2966 ** past the end of the first SQL statement in zSql. These routines only
2967 ** compile the first statement in zSql, so *pzTail is left pointing to
2968 ** what remains uncompiled.
2969 **
2970 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
2971 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
2972 ** to NULL. ^If the input text contains no SQL (if the input is an empty
2973 ** string or a comment) then *ppStmt is set to NULL.
2974 ** The calling procedure is responsible for deleting the compiled
2975 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
2976 ** ppStmt may not be NULL.
2977 **
2978 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
2979 ** otherwise an [error code] is returned.
2980 **
2981 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
2982 ** recommended for all new programs. The two older interfaces are retained
2983 ** for backwards compatibility, but their use is discouraged.
2984 ** ^In the "v2" interfaces, the prepared statement
2985 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
2986 ** original SQL text. This causes the [sqlite3_step()] interface to
2987 ** behave differently in three ways:
2988 **
2989 ** <ol>
2990 ** <li>
2991 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
2992 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
2993 ** statement and try to run it again.
2994 ** </li>
2995 **
2996 ** <li>
2997 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
2998 ** [error codes] or [extended error codes]. ^The legacy behavior was that
2999 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3000 ** and the application would have to make a second call to [sqlite3_reset()]
3001 ** in order to find the underlying cause of the problem. With the "v2" prepare
3002 ** interfaces, the underlying reason for the error is returned immediately.
3003 ** </li>
3004 **
3005 ** <li>
3006 ** ^If the specific value bound to [parameter | host parameter] in the
3007 ** WHERE clause might influence the choice of query plan for a statement,
3008 ** then the statement will be automatically recompiled, as if there had been
3009 ** a schema change, on the first [sqlite3_step()] call following any change
3010 ** to the [sqlite3_bind_text | bindings] of that [parameter].
3011 ** ^The specific value of WHERE-clause [parameter] might influence the
3012 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
3013 ** or [GLOB] operator or if the parameter is compared to an indexed column
3014 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3015 ** the
3016 ** </li>
3017 ** </ol>
3018 */
3019 SQLITE_API int sqlite3_prepare(
3020 sqlite3 *db, /* Database handle */
3021 const char *zSql, /* SQL statement, UTF-8 encoded */
3022 int nByte, /* Maximum length of zSql in bytes. */
3023 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3024 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3025 );
3026 SQLITE_API int sqlite3_prepare_v2(
3027 sqlite3 *db, /* Database handle */
3028 const char *zSql, /* SQL statement, UTF-8 encoded */
3029 int nByte, /* Maximum length of zSql in bytes. */
3030 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3031 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3032 );
3033 SQLITE_API int sqlite3_prepare16(
3034 sqlite3 *db, /* Database handle */
3035 const void *zSql, /* SQL statement, UTF-16 encoded */
3036 int nByte, /* Maximum length of zSql in bytes. */
3037 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3038 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3039 );
3040 SQLITE_API int sqlite3_prepare16_v2(
3041 sqlite3 *db, /* Database handle */
3042 const void *zSql, /* SQL statement, UTF-16 encoded */
3043 int nByte, /* Maximum length of zSql in bytes. */
3044 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3045 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3046 );
3047
3048 /*
3049 ** CAPI3REF: Retrieving Statement SQL
3050 **
3051 ** ^This interface can be used to retrieve a saved copy of the original
3052 ** SQL text used to create a [prepared statement] if that statement was
3053 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3054 */
3055 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3056
3057 /*
3058 ** CAPI3REF: Determine If An SQL Statement Writes The Database
3059 **
3060 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3061 ** and only if the [prepared statement] X makes no direct changes to
3062 ** the content of the database file.
3063 **
3064 ** Note that [application-defined SQL functions] or
3065 ** [virtual tables] might change the database indirectly as a side effect.
3066 ** ^(For example, if an application defines a function "eval()" that
3067 ** calls [sqlite3_exec()], then the following SQL statement would
3068 ** change the database file through side-effects:
3069 **
3070 ** <blockquote><pre>
3071 ** SELECT eval('DELETE FROM t1') FROM t2;
3072 ** </pre></blockquote>
3073 **
3074 ** But because the [SELECT] statement does not change the database file
3075 ** directly, sqlite3_stmt_readonly() would still return true.)^
3076 **
3077 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3078 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3079 ** since the statements themselves do not actually modify the database but
3080 ** rather they control the timing of when other statements modify the
3081 ** database. ^The [ATTACH] and [DETACH] statements also cause
3082 ** sqlite3_stmt_readonly() to return true since, while those statements
3083 ** change the configuration of a database connection, they do not make
3084 ** changes to the content of the database files on disk.
3085 */
3086 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3087
3088 /*
3089 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3090 **
3091 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3092 ** [prepared statement] S has been stepped at least once using
3093 ** [sqlite3_step(S)] but has not run to completion and/or has not
3094 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3095 ** interface returns false if S is a NULL pointer. If S is not a
3096 ** NULL pointer and is not a pointer to a valid [prepared statement]
3097 ** object, then the behavior is undefined and probably undesirable.
3098 **
3099 ** This interface can be used in combination [sqlite3_next_stmt()]
3100 ** to locate all prepared statements associated with a database
3101 ** connection that are in need of being reset. This can be used,
3102 ** for example, in diagnostic routines to search for prepared
3103 ** statements that are holding a transaction open.
3104 */
3105 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3106
3107 /*
3108 ** CAPI3REF: Dynamically Typed Value Object
3109 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3110 **
3111 ** SQLite uses the sqlite3_value object to represent all values
3112 ** that can be stored in a database table. SQLite uses dynamic typing
3113 ** for the values it stores. ^Values stored in sqlite3_value objects
3114 ** can be integers, floating point values, strings, BLOBs, or NULL.
3115 **
3116 ** An sqlite3_value object may be either "protected" or "unprotected".
3117 ** Some interfaces require a protected sqlite3_value. Other interfaces
3118 ** will accept either a protected or an unprotected sqlite3_value.
3119 ** Every interface that accepts sqlite3_value arguments specifies
3120 ** whether or not it requires a protected sqlite3_value.
3121 **
3122 ** The terms "protected" and "unprotected" refer to whether or not
3123 ** a mutex is held. An internal mutex is held for a protected
3124 ** sqlite3_value object but no mutex is held for an unprotected
3125 ** sqlite3_value object. If SQLite is compiled to be single-threaded
3126 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3127 ** or if SQLite is run in one of reduced mutex modes
3128 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3129 ** then there is no distinction between protected and unprotected
3130 ** sqlite3_value objects and they can be used interchangeably. However,
3131 ** for maximum code portability it is recommended that applications
3132 ** still make the distinction between protected and unprotected
3133 ** sqlite3_value objects even when not strictly required.
3134 **
3135 ** ^The sqlite3_value objects that are passed as parameters into the
3136 ** implementation of [application-defined SQL functions] are protected.
3137 ** ^The sqlite3_value object returned by
3138 ** [sqlite3_column_value()] is unprotected.
3139 ** Unprotected sqlite3_value objects may only be used with
3140 ** [sqlite3_result_value()] and [sqlite3_bind_value()].
3141 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
3142 ** interfaces require protected sqlite3_value objects.
3143 */
3144 typedef struct Mem sqlite3_value;
3145
3146 /*
3147 ** CAPI3REF: SQL Function Context Object
3148 **
3149 ** The context in which an SQL function executes is stored in an
3150 ** sqlite3_context object. ^A pointer to an sqlite3_context object
3151 ** is always first parameter to [application-defined SQL functions].
3152 ** The application-defined SQL function implementation will pass this
3153 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3154 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3155 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3156 ** and/or [sqlite3_set_auxdata()].
3157 */
3158 typedef struct sqlite3_context sqlite3_context;
3159
3160 /*
3161 ** CAPI3REF: Binding Values To Prepared Statements
3162 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3163 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3164 **
3165 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3166 ** literals may be replaced by a [parameter] that matches one of following
3167 ** templates:
3168 **
3169 ** <ul>
3170 ** <li> ?
3171 ** <li> ?NNN
3172 ** <li> :VVV
3173 ** <li> @VVV
3174 ** <li> $VVV
3175 ** </ul>
3176 **
3177 ** In the templates above, NNN represents an integer literal,
3178 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
3179 ** parameters (also called "host parameter names" or "SQL parameters")
3180 ** can be set using the sqlite3_bind_*() routines defined here.
3181 **
3182 ** ^The first argument to the sqlite3_bind_*() routines is always
3183 ** a pointer to the [sqlite3_stmt] object returned from
3184 ** [sqlite3_prepare_v2()] or its variants.
3185 **
3186 ** ^The second argument is the index of the SQL parameter to be set.
3187 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
3188 ** SQL parameter is used more than once, second and subsequent
3189 ** occurrences have the same index as the first occurrence.
3190 ** ^The index for named parameters can be looked up using the
3191 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
3192 ** for "?NNN" parameters is the value of NNN.
3193 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
3194 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3195 **
3196 ** ^The third argument is the value to bind to the parameter.
3197 **
3198 ** ^(In those routines that have a fourth argument, its value is the
3199 ** number of bytes in the parameter. To be clear: the value is the
3200 ** number of <u>bytes</u> in the value, not the number of characters.)^
3201 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3202 ** is negative, then the length of the string is
3203 ** the number of bytes up to the first zero terminator.
3204 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
3205 ** the behavior is undefined.
3206 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3207 ** or sqlite3_bind_text16() then that parameter must be the byte offset
3208 ** where the NUL terminator would occur assuming the string were NUL
3209 ** terminated. If any NUL characters occur at byte offsets less than
3210 ** the value of the fourth parameter then the resulting string value will
3211 ** contain embedded NULs. The result of expressions involving strings
3212 ** with embedded NULs is undefined.
3213 **
3214 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
3215 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
3216 ** string after SQLite has finished with it. ^The destructor is called
3217 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(),
3218 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails.
3219 ** ^If the fifth argument is
3220 ** the special value [SQLITE_STATIC], then SQLite assumes that the
3221 ** information is in static, unmanaged space and does not need to be freed.
3222 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3223 ** SQLite makes its own private copy of the data immediately, before
3224 ** the sqlite3_bind_*() routine returns.
3225 **
3226 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3227 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3228 ** (just an integer to hold its size) while it is being processed.
3229 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
3230 ** content is later written using
3231 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
3232 ** ^A negative value for the zeroblob results in a zero-length BLOB.
3233 **
3234 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3235 ** for the [prepared statement] or with a prepared statement for which
3236 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3237 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3238 ** routine is passed a [prepared statement] that has been finalized, the
3239 ** result is undefined and probably harmful.
3240 **
3241 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3242 ** ^Unbound parameters are interpreted as NULL.
3243 **
3244 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3245 ** [error code] if anything goes wrong.
3246 ** ^[SQLITE_RANGE] is returned if the parameter
3247 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3248 **
3249 ** See also: [sqlite3_bind_parameter_count()],
3250 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3251 */
3252 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3253 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
3254 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
3255 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3256 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
3257 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
3258 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3259 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3260 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3261
3262 /*
3263 ** CAPI3REF: Number Of SQL Parameters
3264 **
3265 ** ^This routine can be used to find the number of [SQL parameters]
3266 ** in a [prepared statement]. SQL parameters are tokens of the
3267 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3268 ** placeholders for values that are [sqlite3_bind_blob | bound]
3269 ** to the parameters at a later time.
3270 **
3271 ** ^(This routine actually returns the index of the largest (rightmost)
3272 ** parameter. For all forms except ?NNN, this will correspond to the
3273 ** number of unique parameters. If parameters of the ?NNN form are used,
3274 ** there may be gaps in the list.)^
3275 **
3276 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3277 ** [sqlite3_bind_parameter_name()], and
3278 ** [sqlite3_bind_parameter_index()].
3279 */
3280 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
3281
3282 /*
3283 ** CAPI3REF: Name Of A Host Parameter
3284 **
3285 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
3286 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
3287 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3288 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3289 ** respectively.
3290 ** In other words, the initial ":" or "$" or "@" or "?"
3291 ** is included as part of the name.)^
3292 ** ^Parameters of the form "?" without a following integer have no name
3293 ** and are referred to as "nameless" or "anonymous parameters".
3294 **
3295 ** ^The first host parameter has an index of 1, not 0.
3296 **
3297 ** ^If the value N is out of range or if the N-th parameter is
3298 ** nameless, then NULL is returned. ^The returned string is
3299 ** always in UTF-8 encoding even if the named parameter was
3300 ** originally specified as UTF-16 in [sqlite3_prepare16()] or
3301 ** [sqlite3_prepare16_v2()].
3302 **
3303 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3304 ** [sqlite3_bind_parameter_count()], and
3305 ** [sqlite3_bind_parameter_index()].
3306 */
3307 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3308
3309 /*
3310 ** CAPI3REF: Index Of A Parameter With A Given Name
3311 **
3312 ** ^Return the index of an SQL parameter given its name. ^The
3313 ** index value returned is suitable for use as the second
3314 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3315 ** is returned if no matching parameter is found. ^The parameter
3316 ** name must be given in UTF-8 even if the original statement
3317 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3318 **
3319 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
3320 ** [sqlite3_bind_parameter_count()], and
3321 ** [sqlite3_bind_parameter_index()].
3322 */
3323 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3324
3325 /*
3326 ** CAPI3REF: Reset All Bindings On A Prepared Statement
3327 **
3328 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3329 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3330 ** ^Use this routine to reset all host parameters to NULL.
3331 */
3332 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
3333
3334 /*
3335 ** CAPI3REF: Number Of Columns In A Result Set
3336 **
3337 ** ^Return the number of columns in the result set returned by the
3338 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3339 ** statement that does not return data (for example an [UPDATE]).
3340 **
3341 ** See also: [sqlite3_data_count()]
3342 */
3343 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
3344
3345 /*
3346 ** CAPI3REF: Column Names In A Result Set
3347 **
3348 ** ^These routines return the name assigned to a particular column
3349 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3350 ** interface returns a pointer to a zero-terminated UTF-8 string
3351 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
3352 ** UTF-16 string. ^The first parameter is the [prepared statement]
3353 ** that implements the [SELECT] statement. ^The second parameter is the
3354 ** column number. ^The leftmost column is number 0.
3355 **
3356 ** ^The returned string pointer is valid until either the [prepared statement]
3357 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3358 ** reprepared by the first call to [sqlite3_step()] for a particular run
3359 ** or until the next call to
3360 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3361 **
3362 ** ^If sqlite3_malloc() fails during the processing of either routine
3363 ** (for example during a conversion from UTF-8 to UTF-16) then a
3364 ** NULL pointer is returned.
3365 **
3366 ** ^The name of a result column is the value of the "AS" clause for
3367 ** that column, if there is an AS clause. If there is no AS clause
3368 ** then the name of the column is unspecified and may change from
3369 ** one release of SQLite to the next.
3370 */
3371 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
3372 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
3373
3374 /*
3375 ** CAPI3REF: Source Of Data In A Query Result
3376 **
3377 ** ^These routines provide a means to determine the database, table, and
3378 ** table column that is the origin of a particular result column in
3379 ** [SELECT] statement.
3380 ** ^The name of the database or table or column can be returned as
3381 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3382 ** the database name, the _table_ routines return the table name, and
3383 ** the origin_ routines return the column name.
3384 ** ^The returned string is valid until the [prepared statement] is destroyed
3385 ** using [sqlite3_finalize()] or until the statement is automatically
3386 ** reprepared by the first call to [sqlite3_step()] for a particular run
3387 ** or until the same information is requested
3388 ** again in a different encoding.
3389 **
3390 ** ^The names returned are the original un-aliased names of the
3391 ** database, table, and column.
3392 **
3393 ** ^The first argument to these interfaces is a [prepared statement].
3394 ** ^These functions return information about the Nth result column returned by
3395 ** the statement, where N is the second function argument.
3396 ** ^The left-most column is column 0 for these routines.
3397 **
3398 ** ^If the Nth column returned by the statement is an expression or
3399 ** subquery and is not a column value, then all of these functions return
3400 ** NULL. ^These routine might also return NULL if a memory allocation error
3401 ** occurs. ^Otherwise, they return the name of the attached database, table,
3402 ** or column that query result column was extracted from.
3403 **
3404 ** ^As with all other SQLite APIs, those whose names end with "16" return
3405 ** UTF-16 encoded strings and the other functions return UTF-8.
3406 **
3407 ** ^These APIs are only available if the library was compiled with the
3408 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3409 **
3410 ** If two or more threads call one or more of these routines against the same
3411 ** prepared statement and column at the same time then the results are
3412 ** undefined.
3413 **
3414 ** If two or more threads call one or more
3415 ** [sqlite3_column_database_name | column metadata interfaces]
3416 ** for the same [prepared statement] and result column
3417 ** at the same time then the results are undefined.
3418 */
3419 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
3420 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
3421 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
3422 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
3423 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
3424 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
3425
3426 /*
3427 ** CAPI3REF: Declared Datatype Of A Query Result
3428 **
3429 ** ^(The first parameter is a [prepared statement].
3430 ** If this statement is a [SELECT] statement and the Nth column of the
3431 ** returned result set of that [SELECT] is a table column (not an
3432 ** expression or subquery) then the declared type of the table
3433 ** column is returned.)^ ^If the Nth column of the result set is an
3434 ** expression or subquery, then a NULL pointer is returned.
3435 ** ^The returned string is always UTF-8 encoded.
3436 **
3437 ** ^(For example, given the database schema:
3438 **
3439 ** CREATE TABLE t1(c1 VARIANT);
3440 **
3441 ** and the following statement to be compiled:
3442 **
3443 ** SELECT c1 + 1, c1 FROM t1;
3444 **
3445 ** this routine would return the string "VARIANT" for the second result
3446 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
3447 **
3448 ** ^SQLite uses dynamic run-time typing. ^So just because a column
3449 ** is declared to contain a particular type does not mean that the
3450 ** data stored in that column is of the declared type. SQLite is
3451 ** strongly typed, but the typing is dynamic not static. ^Type
3452 ** is associated with individual values, not with the containers
3453 ** used to hold those values.
3454 */
3455 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
3456 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
3457
3458 /*
3459 ** CAPI3REF: Evaluate An SQL Statement
3460 **
3461 ** After a [prepared statement] has been prepared using either
3462 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3463 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3464 ** must be called one or more times to evaluate the statement.
3465 **
3466 ** The details of the behavior of the sqlite3_step() interface depend
3467 ** on whether the statement was prepared using the newer "v2" interface
3468 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3469 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3470 ** new "v2" interface is recommended for new applications but the legacy
3471 ** interface will continue to be supported.
3472 **
3473 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3474 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3475 ** ^With the "v2" interface, any of the other [result codes] or
3476 ** [extended result codes] might be returned as well.
3477 **
3478 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3479 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
3480 ** or occurs outside of an explicit transaction, then you can retry the
3481 ** statement. If the statement is not a [COMMIT] and occurs within an
3482 ** explicit transaction then you should rollback the transaction before
3483 ** continuing.
3484 **
3485 ** ^[SQLITE_DONE] means that the statement has finished executing
3486 ** successfully. sqlite3_step() should not be called again on this virtual
3487 ** machine without first calling [sqlite3_reset()] to reset the virtual
3488 ** machine back to its initial state.
3489 **
3490 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3491 ** is returned each time a new row of data is ready for processing by the
3492 ** caller. The values may be accessed using the [column access functions].
3493 ** sqlite3_step() is called again to retrieve the next row of data.
3494 **
3495 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3496 ** violation) has occurred. sqlite3_step() should not be called again on
3497 ** the VM. More information may be found by calling [sqlite3_errmsg()].
3498 ** ^With the legacy interface, a more specific error code (for example,
3499 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3500 ** can be obtained by calling [sqlite3_reset()] on the
3501 ** [prepared statement]. ^In the "v2" interface,
3502 ** the more specific error code is returned directly by sqlite3_step().
3503 **
3504 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3505 ** Perhaps it was called on a [prepared statement] that has
3506 ** already been [sqlite3_finalize | finalized] or on one that had
3507 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3508 ** be the case that the same database connection is being used by two or
3509 ** more threads at the same moment in time.
3510 **
3511 ** For all versions of SQLite up to and including 3.6.23.1, a call to
3512 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
3513 ** other than [SQLITE_ROW] before any subsequent invocation of
3514 ** sqlite3_step(). Failure to reset the prepared statement using
3515 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3516 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
3517 ** calling [sqlite3_reset()] automatically in this circumstance rather
3518 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
3519 ** break because any application that ever receives an SQLITE_MISUSE error
3520 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
3521 ** can be used to restore the legacy behavior.
3522 **
3523 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3524 ** API always returns a generic error code, [SQLITE_ERROR], following any
3525 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3526 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3527 ** specific [error codes] that better describes the error.
3528 ** We admit that this is a goofy design. The problem has been fixed
3529 ** with the "v2" interface. If you prepare all of your SQL statements
3530 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3531 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3532 ** then the more specific [error codes] are returned directly
3533 ** by sqlite3_step(). The use of the "v2" interface is recommended.
3534 */
3535 SQLITE_API int sqlite3_step(sqlite3_stmt*);
3536
3537 /*
3538 ** CAPI3REF: Number of columns in a result set
3539 **
3540 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
3541 ** current row of the result set of [prepared statement] P.
3542 ** ^If prepared statement P does not have results ready to return
3543 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3544 ** interfaces) then sqlite3_data_count(P) returns 0.
3545 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3546 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3547 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
3548 ** will return non-zero if previous call to [sqlite3_step](P) returned
3549 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3550 ** where it always returns zero since each step of that multi-step
3551 ** pragma returns 0 columns of data.
3552 **
3553 ** See also: [sqlite3_column_count()]
3554 */
3555 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
3556
3557 /*
3558 ** CAPI3REF: Fundamental Datatypes
3559 ** KEYWORDS: SQLITE_TEXT
3560 **
3561 ** ^(Every value in SQLite has one of five fundamental datatypes:
3562 **
3563 ** <ul>
3564 ** <li> 64-bit signed integer
3565 ** <li> 64-bit IEEE floating point number
3566 ** <li> string
3567 ** <li> BLOB
3568 ** <li> NULL
3569 ** </ul>)^
3570 **
3571 ** These constants are codes for each of those types.
3572 **
3573 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3574 ** for a completely different meaning. Software that links against both
3575 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3576 ** SQLITE_TEXT.
3577 */
3578 #define SQLITE_INTEGER 1
3579 #define SQLITE_FLOAT 2
3580 #define SQLITE_BLOB 4
3581 #define SQLITE_NULL 5
3582 #ifdef SQLITE_TEXT
3583 # undef SQLITE_TEXT
3584 #else
3585 # define SQLITE_TEXT 3
3586 #endif
3587 #define SQLITE3_TEXT 3
3588
3589 /*
3590 ** CAPI3REF: Result Values From A Query
3591 ** KEYWORDS: {column access functions}
3592 **
3593 ** These routines form the "result set" interface.
3594 **
3595 ** ^These routines return information about a single column of the current
3596 ** result row of a query. ^In every case the first argument is a pointer
3597 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3598 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3599 ** and the second argument is the index of the column for which information
3600 ** should be returned. ^The leftmost column of the result set has the index 0.
3601 ** ^The number of columns in the result can be determined using
3602 ** [sqlite3_column_count()].
3603 **
3604 ** If the SQL statement does not currently point to a valid row, or if the
3605 ** column index is out of range, the result is undefined.
3606 ** These routines may only be called when the most recent call to
3607 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3608 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3609 ** If any of these routines are called after [sqlite3_reset()] or
3610 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3611 ** something other than [SQLITE_ROW], the results are undefined.
3612 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
3613 ** are called from a different thread while any of these routines
3614 ** are pending, then the results are undefined.
3615 **
3616 ** ^The sqlite3_column_type() routine returns the
3617 ** [SQLITE_INTEGER | datatype code] for the initial data type
3618 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
3619 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
3620 ** returned by sqlite3_column_type() is only meaningful if no type
3621 ** conversions have occurred as described below. After a type conversion,
3622 ** the value returned by sqlite3_column_type() is undefined. Future
3623 ** versions of SQLite may change the behavior of sqlite3_column_type()
3624 ** following a type conversion.
3625 **
3626 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
3627 ** routine returns the number of bytes in that BLOB or string.
3628 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
3629 ** the string to UTF-8 and then returns the number of bytes.
3630 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
3631 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
3632 ** the number of bytes in that string.
3633 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
3634 **
3635 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
3636 ** routine returns the number of bytes in that BLOB or string.
3637 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
3638 ** the string to UTF-16 and then returns the number of bytes.
3639 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
3640 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
3641 ** the number of bytes in that string.
3642 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
3643 **
3644 ** ^The values returned by [sqlite3_column_bytes()] and
3645 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
3646 ** of the string. ^For clarity: the values returned by
3647 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
3648 ** bytes in the string, not the number of characters.
3649 **
3650 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
3651 ** even empty strings, are always zero-terminated. ^The return
3652 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
3653 **
3654 ** ^The object returned by [sqlite3_column_value()] is an
3655 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object
3656 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
3657 ** If the [unprotected sqlite3_value] object returned by
3658 ** [sqlite3_column_value()] is used in any other way, including calls
3659 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
3660 ** or [sqlite3_value_bytes()], then the behavior is undefined.
3661 **
3662 ** These routines attempt to convert the value where appropriate. ^For
3663 ** example, if the internal representation is FLOAT and a text result
3664 ** is requested, [sqlite3_snprintf()] is used internally to perform the
3665 ** conversion automatically. ^(The following table details the conversions
3666 ** that are applied:
3667 **
3668 ** <blockquote>
3669 ** <table border="1">
3670 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
3671 **
3672 ** <tr><td> NULL <td> INTEGER <td> Result is 0
3673 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
3674 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer
3675 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer
3676 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
3677 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
3678 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
3679 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer
3680 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
3681 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT
3682 ** <tr><td> TEXT <td> INTEGER <td> Use atoi()
3683 ** <tr><td> TEXT <td> FLOAT <td> Use atof()
3684 ** <tr><td> TEXT <td> BLOB <td> No change
3685 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi()
3686 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof()
3687 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
3688 ** </table>
3689 ** </blockquote>)^
3690 **
3691 ** The table above makes reference to standard C library functions atoi()
3692 ** and atof(). SQLite does not really use these functions. It has its
3693 ** own equivalent internal routines. The atoi() and atof() names are
3694 ** used in the table for brevity and because they are familiar to most
3695 ** C programmers.
3696 **
3697 ** Note that when type conversions occur, pointers returned by prior
3698 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
3699 ** sqlite3_column_text16() may be invalidated.
3700 ** Type conversions and pointer invalidations might occur
3701 ** in the following cases:
3702 **
3703 ** <ul>
3704 ** <li> The initial content is a BLOB and sqlite3_column_text() or
3705 ** sqlite3_column_text16() is called. A zero-terminator might
3706 ** need to be added to the string.</li>
3707 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
3708 ** sqlite3_column_text16() is called. The content must be converted
3709 ** to UTF-16.</li>
3710 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
3711 ** sqlite3_column_text() is called. The content must be converted
3712 ** to UTF-8.</li>
3713 ** </ul>
3714 **
3715 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
3716 ** not invalidate a prior pointer, though of course the content of the buffer
3717 ** that the prior pointer references will have been modified. Other kinds
3718 ** of conversion are done in place when it is possible, but sometimes they
3719 ** are not possible and in those cases prior pointers are invalidated.
3720 **
3721 ** The safest and easiest to remember policy is to invoke these routines
3722 ** in one of the following ways:
3723 **
3724 ** <ul>
3725 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
3726 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
3727 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
3728 ** </ul>
3729 **
3730 ** In other words, you should call sqlite3_column_text(),
3731 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
3732 ** into the desired format, then invoke sqlite3_column_bytes() or
3733 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
3734 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
3735 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
3736 ** with calls to sqlite3_column_bytes().
3737 **
3738 ** ^The pointers returned are valid until a type conversion occurs as
3739 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
3740 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
3741 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned
3742 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
3743 ** [sqlite3_free()].
3744 **
3745 ** ^(If a memory allocation error occurs during the evaluation of any
3746 ** of these routines, a default value is returned. The default value
3747 ** is either the integer 0, the floating point number 0.0, or a NULL
3748 ** pointer. Subsequent calls to [sqlite3_errcode()] will return
3749 ** [SQLITE_NOMEM].)^
3750 */
3751 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
3752 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
3753 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
3754 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
3755 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
3756 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
3757 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
3758 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
3759 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
3760 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
3761
3762 /*
3763 ** CAPI3REF: Destroy A Prepared Statement Object
3764 **
3765 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
3766 ** ^If the most recent evaluation of the statement encountered no errors
3767 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
3768 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
3769 ** sqlite3_finalize(S) returns the appropriate [error code] or
3770 ** [extended error code].
3771 **
3772 ** ^The sqlite3_finalize(S) routine can be called at any point during
3773 ** the life cycle of [prepared statement] S:
3774 ** before statement S is ever evaluated, after
3775 ** one or more calls to [sqlite3_reset()], or after any call
3776 ** to [sqlite3_step()] regardless of whether or not the statement has
3777 ** completed execution.
3778 **
3779 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
3780 **
3781 ** The application must finalize every [prepared statement] in order to avoid
3782 ** resource leaks. It is a grievous error for the application to try to use
3783 ** a prepared statement after it has been finalized. Any use of a prepared
3784 ** statement after it has been finalized can result in undefined and
3785 ** undesirable behavior such as segfaults and heap corruption.
3786 */
3787 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
3788
3789 /*
3790 ** CAPI3REF: Reset A Prepared Statement Object
3791 **
3792 ** The sqlite3_reset() function is called to reset a [prepared statement]
3793 ** object back to its initial state, ready to be re-executed.
3794 ** ^Any SQL statement variables that had values bound to them using
3795 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
3796 ** Use [sqlite3_clear_bindings()] to reset the bindings.
3797 **
3798 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
3799 ** back to the beginning of its program.
3800 **
3801 ** ^If the most recent call to [sqlite3_step(S)] for the
3802 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
3803 ** or if [sqlite3_step(S)] has never before been called on S,
3804 ** then [sqlite3_reset(S)] returns [SQLITE_OK].
3805 **
3806 ** ^If the most recent call to [sqlite3_step(S)] for the
3807 ** [prepared statement] S indicated an error, then
3808 ** [sqlite3_reset(S)] returns an appropriate [error code].
3809 **
3810 ** ^The [sqlite3_reset(S)] interface does not change the values
3811 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
3812 */
3813 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
3814
3815 /*
3816 ** CAPI3REF: Create Or Redefine SQL Functions
3817 ** KEYWORDS: {function creation routines}
3818 ** KEYWORDS: {application-defined SQL function}
3819 ** KEYWORDS: {application-defined SQL functions}
3820 **
3821 ** ^These functions (collectively known as "function creation routines")
3822 ** are used to add SQL functions or aggregates or to redefine the behavior
3823 ** of existing SQL functions or aggregates. The only differences between
3824 ** these routines are the text encoding expected for
3825 ** the second parameter (the name of the function being created)
3826 ** and the presence or absence of a destructor callback for
3827 ** the application data pointer.
3828 **
3829 ** ^The first parameter is the [database connection] to which the SQL
3830 ** function is to be added. ^If an application uses more than one database
3831 ** connection then application-defined SQL functions must be added
3832 ** to each database connection separately.
3833 **
3834 ** ^The second parameter is the name of the SQL function to be created or
3835 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
3836 ** representation, exclusive of the zero-terminator. ^Note that the name
3837 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
3838 ** ^Any attempt to create a function with a longer name
3839 ** will result in [SQLITE_MISUSE] being returned.
3840 **
3841 ** ^The third parameter (nArg)
3842 ** is the number of arguments that the SQL function or
3843 ** aggregate takes. ^If this parameter is -1, then the SQL function or
3844 ** aggregate may take any number of arguments between 0 and the limit
3845 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
3846 ** parameter is less than -1 or greater than 127 then the behavior is
3847 ** undefined.
3848 **
3849 ** ^The fourth parameter, eTextRep, specifies what
3850 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
3851 ** its parameters. Every SQL function implementation must be able to work
3852 ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be
3853 ** more efficient with one encoding than another. ^An application may
3854 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
3855 ** times with the same function but with different values of eTextRep.
3856 ** ^When multiple implementations of the same function are available, SQLite
3857 ** will pick the one that involves the least amount of data conversion.
3858 ** If there is only a single implementation which does not care what text
3859 ** encoding is used, then the fourth argument should be [SQLITE_ANY].
3860 **
3861 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
3862 ** function can gain access to this pointer using [sqlite3_user_data()].)^
3863 **
3864 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
3865 ** pointers to C-language functions that implement the SQL function or
3866 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
3867 ** callback only; NULL pointers must be passed as the xStep and xFinal
3868 ** parameters. ^An aggregate SQL function requires an implementation of xStep
3869 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
3870 ** SQL function or aggregate, pass NULL pointers for all three function
3871 ** callbacks.
3872 **
3873 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
3874 ** then it is destructor for the application data pointer.
3875 ** The destructor is invoked when the function is deleted, either by being
3876 ** overloaded or when the database connection closes.)^
3877 ** ^The destructor is also invoked if the call to
3878 ** sqlite3_create_function_v2() fails.
3879 ** ^When the destructor callback of the tenth parameter is invoked, it
3880 ** is passed a single argument which is a copy of the application data
3881 ** pointer which was the fifth parameter to sqlite3_create_function_v2().
3882 **
3883 ** ^It is permitted to register multiple implementations of the same
3884 ** functions with the same name but with either differing numbers of
3885 ** arguments or differing preferred text encodings. ^SQLite will use
3886 ** the implementation that most closely matches the way in which the
3887 ** SQL function is used. ^A function implementation with a non-negative
3888 ** nArg parameter is a better match than a function implementation with
3889 ** a negative nArg. ^A function where the preferred text encoding
3890 ** matches the database encoding is a better
3891 ** match than a function where the encoding is different.
3892 ** ^A function where the encoding difference is between UTF16le and UTF16be
3893 ** is a closer match than a function where the encoding difference is
3894 ** between UTF8 and UTF16.
3895 **
3896 ** ^Built-in functions may be overloaded by new application-defined functions.
3897 **
3898 ** ^An application-defined function is permitted to call other
3899 ** SQLite interfaces. However, such calls must not
3900 ** close the database connection nor finalize or reset the prepared
3901 ** statement in which the function is running.
3902 */
3903 SQLITE_API int sqlite3_create_function(
3904 sqlite3 *db,
3905 const char *zFunctionName,
3906 int nArg,
3907 int eTextRep,
3908 void *pApp,
3909 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3910 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3911 void (*xFinal)(sqlite3_context*)
3912 );
3913 SQLITE_API int sqlite3_create_function16(
3914 sqlite3 *db,
3915 const void *zFunctionName,
3916 int nArg,
3917 int eTextRep,
3918 void *pApp,
3919 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3920 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3921 void (*xFinal)(sqlite3_context*)
3922 );
3923 SQLITE_API int sqlite3_create_function_v2(
3924 sqlite3 *db,
3925 const char *zFunctionName,
3926 int nArg,
3927 int eTextRep,
3928 void *pApp,
3929 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
3930 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
3931 void (*xFinal)(sqlite3_context*),
3932 void(*xDestroy)(void*)
3933 );
3934
3935 /*
3936 ** CAPI3REF: Text Encodings
3937 **
3938 ** These constant define integer codes that represent the various
3939 ** text encodings supported by SQLite.
3940 */
3941 #define SQLITE_UTF8 1
3942 #define SQLITE_UTF16LE 2
3943 #define SQLITE_UTF16BE 3
3944 #define SQLITE_UTF16 4 /* Use native byte order */
3945 #define SQLITE_ANY 5 /* sqlite3_create_function only */
3946 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
3947
3948 /*
3949 ** CAPI3REF: Deprecated Functions
3950 ** DEPRECATED
3951 **
3952 ** These functions are [deprecated]. In order to maintain
3953 ** backwards compatibility with older code, these functions continue
3954 ** to be supported. However, new applications should avoid
3955 ** the use of these functions. To help encourage people to avoid
3956 ** using these functions, we are not going to tell you what they do.
3957 */
3958 #ifndef SQLITE_OMIT_DEPRECATED
3959 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
3960 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
3961 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
3962 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
3963 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
3964 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
3965 #endif
3966
3967 /*
3968 ** CAPI3REF: Obtaining SQL Function Parameter Values
3969 **
3970 ** The C-language implementation of SQL functions and aggregates uses
3971 ** this set of interface routines to access the parameter values on
3972 ** the function or aggregate.
3973 **
3974 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
3975 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
3976 ** define callbacks that implement the SQL functions and aggregates.
3977 ** The 3rd parameter to these callbacks is an array of pointers to
3978 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
3979 ** each parameter to the SQL function. These routines are used to
3980 ** extract values from the [sqlite3_value] objects.
3981 **
3982 ** These routines work only with [protected sqlite3_value] objects.
3983 ** Any attempt to use these routines on an [unprotected sqlite3_value]
3984 ** object results in undefined behavior.
3985 **
3986 ** ^These routines work just like the corresponding [column access functions]
3987 ** except that these routines take a single [protected sqlite3_value] object
3988 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
3989 **
3990 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
3991 ** in the native byte-order of the host machine. ^The
3992 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
3993 ** extract UTF-16 strings as big-endian and little-endian respectively.
3994 **
3995 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
3996 ** numeric affinity to the value. This means that an attempt is
3997 ** made to convert the value to an integer or floating point. If
3998 ** such a conversion is possible without loss of information (in other
3999 ** words, if the value is a string that looks like a number)
4000 ** then the conversion is performed. Otherwise no conversion occurs.
4001 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4002 **
4003 ** Please pay particular attention to the fact that the pointer returned
4004 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4005 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4006 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4007 ** or [sqlite3_value_text16()].
4008 **
4009 ** These routines must be called from the same thread as
4010 ** the SQL function that supplied the [sqlite3_value*] parameters.
4011 */
4012 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4013 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4014 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4015 SQLITE_API double sqlite3_value_double(sqlite3_value*);
4016 SQLITE_API int sqlite3_value_int(sqlite3_value*);
4017 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4018 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4019 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4020 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4021 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4022 SQLITE_API int sqlite3_value_type(sqlite3_value*);
4023 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4024
4025 /*
4026 ** CAPI3REF: Obtain Aggregate Function Context
4027 **
4028 ** Implementations of aggregate SQL functions use this
4029 ** routine to allocate memory for storing their state.
4030 **
4031 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4032 ** for a particular aggregate function, SQLite
4033 ** allocates N of memory, zeroes out that memory, and returns a pointer
4034 ** to the new memory. ^On second and subsequent calls to
4035 ** sqlite3_aggregate_context() for the same aggregate function instance,
4036 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
4037 ** called once for each invocation of the xStep callback and then one
4038 ** last time when the xFinal callback is invoked. ^(When no rows match
4039 ** an aggregate query, the xStep() callback of the aggregate function
4040 ** implementation is never called and xFinal() is called exactly once.
4041 ** In those cases, sqlite3_aggregate_context() might be called for the
4042 ** first time from within xFinal().)^
4043 **
4044 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
4045 ** less than or equal to zero or if a memory allocate error occurs.
4046 **
4047 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4048 ** determined by the N parameter on first successful call. Changing the
4049 ** value of N in subsequent call to sqlite3_aggregate_context() within
4050 ** the same aggregate function instance will not resize the memory
4051 ** allocation.)^
4052 **
4053 ** ^SQLite automatically frees the memory allocated by
4054 ** sqlite3_aggregate_context() when the aggregate query concludes.
4055 **
4056 ** The first parameter must be a copy of the
4057 ** [sqlite3_context | SQL function context] that is the first parameter
4058 ** to the xStep or xFinal callback routine that implements the aggregate
4059 ** function.
4060 **
4061 ** This routine must be called from the same thread in which
4062 ** the aggregate SQL function is running.
4063 */
4064 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4065
4066 /*
4067 ** CAPI3REF: User Data For Functions
4068 **
4069 ** ^The sqlite3_user_data() interface returns a copy of
4070 ** the pointer that was the pUserData parameter (the 5th parameter)
4071 ** of the [sqlite3_create_function()]
4072 ** and [sqlite3_create_function16()] routines that originally
4073 ** registered the application defined function.
4074 **
4075 ** This routine must be called from the same thread in which
4076 ** the application-defined function is running.
4077 */
4078 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
4079
4080 /*
4081 ** CAPI3REF: Database Connection For Functions
4082 **
4083 ** ^The sqlite3_context_db_handle() interface returns a copy of
4084 ** the pointer to the [database connection] (the 1st parameter)
4085 ** of the [sqlite3_create_function()]
4086 ** and [sqlite3_create_function16()] routines that originally
4087 ** registered the application defined function.
4088 */
4089 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
4090
4091 /*
4092 ** CAPI3REF: Function Auxiliary Data
4093 **
4094 ** The following two functions may be used by scalar SQL functions to
4095 ** associate metadata with argument values. If the same value is passed to
4096 ** multiple invocations of the same SQL function during query execution, under
4097 ** some circumstances the associated metadata may be preserved. This may
4098 ** be used, for example, to add a regular-expression matching scalar
4099 ** function. The compiled version of the regular expression is stored as
4100 ** metadata associated with the SQL value passed as the regular expression
4101 ** pattern. The compiled regular expression can be reused on multiple
4102 ** invocations of the same function so that the original pattern string
4103 ** does not need to be recompiled on each invocation.
4104 **
4105 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4106 ** associated by the sqlite3_set_auxdata() function with the Nth argument
4107 ** value to the application-defined function. ^If no metadata has been ever
4108 ** been set for the Nth argument of the function, or if the corresponding
4109 ** function parameter has changed since the meta-data was set,
4110 ** then sqlite3_get_auxdata() returns a NULL pointer.
4111 **
4112 ** ^The sqlite3_set_auxdata() interface saves the metadata
4113 ** pointed to by its 3rd parameter as the metadata for the N-th
4114 ** argument of the application-defined function. Subsequent
4115 ** calls to sqlite3_get_auxdata() might return this data, if it has
4116 ** not been destroyed.
4117 ** ^If it is not NULL, SQLite will invoke the destructor
4118 ** function given by the 4th parameter to sqlite3_set_auxdata() on
4119 ** the metadata when the corresponding function parameter changes
4120 ** or when the SQL statement completes, whichever comes first.
4121 **
4122 ** SQLite is free to call the destructor and drop metadata on any
4123 ** parameter of any function at any time. ^The only guarantee is that
4124 ** the destructor will be called before the metadata is dropped.
4125 **
4126 ** ^(In practice, metadata is preserved between function calls for
4127 ** expressions that are constant at compile time. This includes literal
4128 ** values and [parameters].)^
4129 **
4130 ** These routines must be called from the same thread in which
4131 ** the SQL function is running.
4132 */
4133 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
4134 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4135
4136
4137 /*
4138 ** CAPI3REF: Constants Defining Special Destructor Behavior
4139 **
4140 ** These are special values for the destructor that is passed in as the
4141 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4142 ** argument is SQLITE_STATIC, it means that the content pointer is constant
4143 ** and will never change. It does not need to be destroyed. ^The
4144 ** SQLITE_TRANSIENT value means that the content will likely change in
4145 ** the near future and that SQLite should make its own private copy of
4146 ** the content before returning.
4147 **
4148 ** The typedef is necessary to work around problems in certain
4149 ** C++ compilers. See ticket #2191.
4150 */
4151 typedef void (*sqlite3_destructor_type)(void*);
4152 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
4153 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4154
4155 /*
4156 ** CAPI3REF: Setting The Result Of An SQL Function
4157 **
4158 ** These routines are used by the xFunc or xFinal callbacks that
4159 ** implement SQL functions and aggregates. See
4160 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
4161 ** for additional information.
4162 **
4163 ** These functions work very much like the [parameter binding] family of
4164 ** functions used to bind values to host parameters in prepared statements.
4165 ** Refer to the [SQL parameter] documentation for additional information.
4166 **
4167 ** ^The sqlite3_result_blob() interface sets the result from
4168 ** an application-defined function to be the BLOB whose content is pointed
4169 ** to by the second parameter and which is N bytes long where N is the
4170 ** third parameter.
4171 **
4172 ** ^The sqlite3_result_zeroblob() interfaces set the result of
4173 ** the application-defined function to be a BLOB containing all zero
4174 ** bytes and N bytes in size, where N is the value of the 2nd parameter.
4175 **
4176 ** ^The sqlite3_result_double() interface sets the result from
4177 ** an application-defined function to be a floating point value specified
4178 ** by its 2nd argument.
4179 **
4180 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4181 ** cause the implemented SQL function to throw an exception.
4182 ** ^SQLite uses the string pointed to by the
4183 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4184 ** as the text of an error message. ^SQLite interprets the error
4185 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
4186 ** interprets the string from sqlite3_result_error16() as UTF-16 in native
4187 ** byte order. ^If the third parameter to sqlite3_result_error()
4188 ** or sqlite3_result_error16() is negative then SQLite takes as the error
4189 ** message all text up through the first zero character.
4190 ** ^If the third parameter to sqlite3_result_error() or
4191 ** sqlite3_result_error16() is non-negative then SQLite takes that many
4192 ** bytes (not characters) from the 2nd parameter as the error message.
4193 ** ^The sqlite3_result_error() and sqlite3_result_error16()
4194 ** routines make a private copy of the error message text before
4195 ** they return. Hence, the calling function can deallocate or
4196 ** modify the text after they return without harm.
4197 ** ^The sqlite3_result_error_code() function changes the error code
4198 ** returned by SQLite as a result of an error in a function. ^By default,
4199 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4200 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4201 **
4202 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4203 ** error indicating that a string or BLOB is too long to represent.
4204 **
4205 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4206 ** error indicating that a memory allocation failed.
4207 **
4208 ** ^The sqlite3_result_int() interface sets the return value
4209 ** of the application-defined function to be the 32-bit signed integer
4210 ** value given in the 2nd argument.
4211 ** ^The sqlite3_result_int64() interface sets the return value
4212 ** of the application-defined function to be the 64-bit signed integer
4213 ** value given in the 2nd argument.
4214 **
4215 ** ^The sqlite3_result_null() interface sets the return value
4216 ** of the application-defined function to be NULL.
4217 **
4218 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
4219 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4220 ** set the return value of the application-defined function to be
4221 ** a text string which is represented as UTF-8, UTF-16 native byte order,
4222 ** UTF-16 little endian, or UTF-16 big endian, respectively.
4223 ** ^SQLite takes the text result from the application from
4224 ** the 2nd parameter of the sqlite3_result_text* interfaces.
4225 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4226 ** is negative, then SQLite takes result text from the 2nd parameter
4227 ** through the first zero character.
4228 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4229 ** is non-negative, then as many bytes (not characters) of the text
4230 ** pointed to by the 2nd parameter are taken as the application-defined
4231 ** function result. If the 3rd parameter is non-negative, then it
4232 ** must be the byte offset into the string where the NUL terminator would
4233 ** appear if the string where NUL terminated. If any NUL characters occur
4234 ** in the string at a byte offset that is less than the value of the 3rd
4235 ** parameter, then the resulting string will contain embedded NULs and the
4236 ** result of expressions operating on strings with embedded NULs is undefined.
4237 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4238 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4239 ** function as the destructor on the text or BLOB result when it has
4240 ** finished using that result.
4241 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4242 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4243 ** assumes that the text or BLOB result is in constant space and does not
4244 ** copy the content of the parameter nor call a destructor on the content
4245 ** when it has finished using that result.
4246 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
4247 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4248 ** then SQLite makes a copy of the result into space obtained from
4249 ** from [sqlite3_malloc()] before it returns.
4250 **
4251 ** ^The sqlite3_result_value() interface sets the result of
4252 ** the application-defined function to be a copy the
4253 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4254 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4255 ** so that the [sqlite3_value] specified in the parameter may change or
4256 ** be deallocated after sqlite3_result_value() returns without harm.
4257 ** ^A [protected sqlite3_value] object may always be used where an
4258 ** [unprotected sqlite3_value] object is required, so either
4259 ** kind of [sqlite3_value] object can be used with this interface.
4260 **
4261 ** If these routines are called from within the different thread
4262 ** than the one containing the application-defined function that received
4263 ** the [sqlite3_context] pointer, the results are undefined.
4264 */
4265 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4266 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
4267 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
4268 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
4269 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
4270 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
4271 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
4272 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
4273 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4274 SQLITE_API void sqlite3_result_null(sqlite3_context*);
4275 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4276 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4277 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4278 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4279 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4280 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
4281
4282 /*
4283 ** CAPI3REF: Define New Collating Sequences
4284 **
4285 ** ^These functions add, remove, or modify a [collation] associated
4286 ** with the [database connection] specified as the first argument.
4287 **
4288 ** ^The name of the collation is a UTF-8 string
4289 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4290 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4291 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4292 ** considered to be the same name.
4293 **
4294 ** ^(The third argument (eTextRep) must be one of the constants:
4295 ** <ul>
4296 ** <li> [SQLITE_UTF8],
4297 ** <li> [SQLITE_UTF16LE],
4298 ** <li> [SQLITE_UTF16BE],
4299 ** <li> [SQLITE_UTF16], or
4300 ** <li> [SQLITE_UTF16_ALIGNED].
4301 ** </ul>)^
4302 ** ^The eTextRep argument determines the encoding of strings passed
4303 ** to the collating function callback, xCallback.
4304 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4305 ** force strings to be UTF16 with native byte order.
4306 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4307 ** on an even byte address.
4308 **
4309 ** ^The fourth argument, pArg, is an application data pointer that is passed
4310 ** through as the first argument to the collating function callback.
4311 **
4312 ** ^The fifth argument, xCallback, is a pointer to the collating function.
4313 ** ^Multiple collating functions can be registered using the same name but
4314 ** with different eTextRep parameters and SQLite will use whichever
4315 ** function requires the least amount of data transformation.
4316 ** ^If the xCallback argument is NULL then the collating function is
4317 ** deleted. ^When all collating functions having the same name are deleted,
4318 ** that collation is no longer usable.
4319 **
4320 ** ^The collating function callback is invoked with a copy of the pArg
4321 ** application data pointer and with two strings in the encoding specified
4322 ** by the eTextRep argument. The collating function must return an
4323 ** integer that is negative, zero, or positive
4324 ** if the first string is less than, equal to, or greater than the second,
4325 ** respectively. A collating function must always return the same answer
4326 ** given the same inputs. If two or more collating functions are registered
4327 ** to the same collation name (using different eTextRep values) then all
4328 ** must give an equivalent answer when invoked with equivalent strings.
4329 ** The collating function must obey the following properties for all
4330 ** strings A, B, and C:
4331 **
4332 ** <ol>
4333 ** <li> If A==B then B==A.
4334 ** <li> If A==B and B==C then A==C.
4335 ** <li> If A&lt;B THEN B&gt;A.
4336 ** <li> If A&lt;B and B&lt;C then A&lt;C.
4337 ** </ol>
4338 **
4339 ** If a collating function fails any of the above constraints and that
4340 ** collating function is registered and used, then the behavior of SQLite
4341 ** is undefined.
4342 **
4343 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4344 ** with the addition that the xDestroy callback is invoked on pArg when
4345 ** the collating function is deleted.
4346 ** ^Collating functions are deleted when they are overridden by later
4347 ** calls to the collation creation functions or when the
4348 ** [database connection] is closed using [sqlite3_close()].
4349 **
4350 ** ^The xDestroy callback is <u>not</u> called if the
4351 ** sqlite3_create_collation_v2() function fails. Applications that invoke
4352 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4353 ** check the return code and dispose of the application data pointer
4354 ** themselves rather than expecting SQLite to deal with it for them.
4355 ** This is different from every other SQLite interface. The inconsistency
4356 ** is unfortunate but cannot be changed without breaking backwards
4357 ** compatibility.
4358 **
4359 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4360 */
4361 SQLITE_API int sqlite3_create_collation(
4362 sqlite3*,
4363 const char *zName,
4364 int eTextRep,
4365 void *pArg,
4366 int(*xCompare)(void*,int,const void*,int,const void*)
4367 );
4368 SQLITE_API int sqlite3_create_collation_v2(
4369 sqlite3*,
4370 const char *zName,
4371 int eTextRep,
4372 void *pArg,
4373 int(*xCompare)(void*,int,const void*,int,const void*),
4374 void(*xDestroy)(void*)
4375 );
4376 SQLITE_API int sqlite3_create_collation16(
4377 sqlite3*,
4378 const void *zName,
4379 int eTextRep,
4380 void *pArg,
4381 int(*xCompare)(void*,int,const void*,int,const void*)
4382 );
4383
4384 /*
4385 ** CAPI3REF: Collation Needed Callbacks
4386 **
4387 ** ^To avoid having to register all collation sequences before a database
4388 ** can be used, a single callback function may be registered with the
4389 ** [database connection] to be invoked whenever an undefined collation
4390 ** sequence is required.
4391 **
4392 ** ^If the function is registered using the sqlite3_collation_needed() API,
4393 ** then it is passed the names of undefined collation sequences as strings
4394 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4395 ** the names are passed as UTF-16 in machine native byte order.
4396 ** ^A call to either function replaces the existing collation-needed callback.
4397 **
4398 ** ^(When the callback is invoked, the first argument passed is a copy
4399 ** of the second argument to sqlite3_collation_needed() or
4400 ** sqlite3_collation_needed16(). The second argument is the database
4401 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4402 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4403 ** sequence function required. The fourth parameter is the name of the
4404 ** required collation sequence.)^
4405 **
4406 ** The callback function should register the desired collation using
4407 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4408 ** [sqlite3_create_collation_v2()].
4409 */
4410 SQLITE_API int sqlite3_collation_needed(
4411 sqlite3*,
4412 void*,
4413 void(*)(void*,sqlite3*,int eTextRep,const char*)
4414 );
4415 SQLITE_API int sqlite3_collation_needed16(
4416 sqlite3*,
4417 void*,
4418 void(*)(void*,sqlite3*,int eTextRep,const void*)
4419 );
4420
4421 #ifdef SQLITE_HAS_CODEC
4422 /*
4423 ** Specify the key for an encrypted database. This routine should be
4424 ** called right after sqlite3_open().
4425 **
4426 ** The code to implement this API is not available in the public release
4427 ** of SQLite.
4428 */
4429 SQLITE_API int sqlite3_key(
4430 sqlite3 *db, /* Database to be rekeyed */
4431 const void *pKey, int nKey /* The key */
4432 );
4433
4434 /*
4435 ** Change the key on an open database. If the current database is not
4436 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4437 ** database is decrypted.
4438 **
4439 ** The code to implement this API is not available in the public release
4440 ** of SQLite.
4441 */
4442 SQLITE_API int sqlite3_rekey(
4443 sqlite3 *db, /* Database to be rekeyed */
4444 const void *pKey, int nKey /* The new key */
4445 );
4446
4447 /*
4448 ** Specify the activation key for a SEE database. Unless
4449 ** activated, none of the SEE routines will work.
4450 */
4451 SQLITE_API void sqlite3_activate_see(
4452 const char *zPassPhrase /* Activation phrase */
4453 );
4454 #endif
4455
4456 #ifdef SQLITE_ENABLE_CEROD
4457 /*
4458 ** Specify the activation key for a CEROD database. Unless
4459 ** activated, none of the CEROD routines will work.
4460 */
4461 SQLITE_API void sqlite3_activate_cerod(
4462 const char *zPassPhrase /* Activation phrase */
4463 );
4464 #endif
4465
4466 /*
4467 ** CAPI3REF: Suspend Execution For A Short Time
4468 **
4469 ** The sqlite3_sleep() function causes the current thread to suspend execution
4470 ** for at least a number of milliseconds specified in its parameter.
4471 **
4472 ** If the operating system does not support sleep requests with
4473 ** millisecond time resolution, then the time will be rounded up to
4474 ** the nearest second. The number of milliseconds of sleep actually
4475 ** requested from the operating system is returned.
4476 **
4477 ** ^SQLite implements this interface by calling the xSleep()
4478 ** method of the default [sqlite3_vfs] object. If the xSleep() method
4479 ** of the default VFS is not implemented correctly, or not implemented at
4480 ** all, then the behavior of sqlite3_sleep() may deviate from the description
4481 ** in the previous paragraphs.
4482 */
4483 SQLITE_API int sqlite3_sleep(int);
4484
4485 /*
4486 ** CAPI3REF: Name Of The Folder Holding Temporary Files
4487 **
4488 ** ^(If this global variable is made to point to a string which is
4489 ** the name of a folder (a.k.a. directory), then all temporary files
4490 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4491 ** will be placed in that directory.)^ ^If this variable
4492 ** is a NULL pointer, then SQLite performs a search for an appropriate
4493 ** temporary file directory.
4494 **
4495 ** It is not safe to read or modify this variable in more than one
4496 ** thread at a time. It is not safe to read or modify this variable
4497 ** if a [database connection] is being used at the same time in a separate
4498 ** thread.
4499 ** It is intended that this variable be set once
4500 ** as part of process initialization and before any SQLite interface
4501 ** routines have been called and that this variable remain unchanged
4502 ** thereafter.
4503 **
4504 ** ^The [temp_store_directory pragma] may modify this variable and cause
4505 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4506 ** the [temp_store_directory pragma] always assumes that any string
4507 ** that this variable points to is held in memory obtained from
4508 ** [sqlite3_malloc] and the pragma may attempt to free that memory
4509 ** using [sqlite3_free].
4510 ** Hence, if this variable is modified directly, either it should be
4511 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4512 ** or else the use of the [temp_store_directory pragma] should be avoided.
4513 **
4514 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
4515 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
4516 ** features that require the use of temporary files may fail. Here is an
4517 ** example of how to do this using C++ with the Windows Runtime:
4518 **
4519 ** <blockquote><pre>
4520 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
4521 ** &nbsp; TemporaryFolder->Path->Data();
4522 ** char zPathBuf&#91;MAX_PATH + 1&#93;;
4523 ** memset(zPathBuf, 0, sizeof(zPathBuf));
4524 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
4525 ** &nbsp; NULL, NULL);
4526 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
4527 ** </pre></blockquote>
4528 */
4529 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
4530
4531 /*
4532 ** CAPI3REF: Name Of The Folder Holding Database Files
4533 **
4534 ** ^(If this global variable is made to point to a string which is
4535 ** the name of a folder (a.k.a. directory), then all database files
4536 ** specified with a relative pathname and created or accessed by
4537 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
4538 ** to be relative to that directory.)^ ^If this variable is a NULL
4539 ** pointer, then SQLite assumes that all database files specified
4540 ** with a relative pathname are relative to the current directory
4541 ** for the process. Only the windows VFS makes use of this global
4542 ** variable; it is ignored by the unix VFS.
4543 **
4544 ** Changing the value of this variable while a database connection is
4545 ** open can result in a corrupt database.
4546 **
4547 ** It is not safe to read or modify this variable in more than one
4548 ** thread at a time. It is not safe to read or modify this variable
4549 ** if a [database connection] is being used at the same time in a separate
4550 ** thread.
4551 ** It is intended that this variable be set once
4552 ** as part of process initialization and before any SQLite interface
4553 ** routines have been called and that this variable remain unchanged
4554 ** thereafter.
4555 **
4556 ** ^The [data_store_directory pragma] may modify this variable and cause
4557 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
4558 ** the [data_store_directory pragma] always assumes that any string
4559 ** that this variable points to is held in memory obtained from
4560 ** [sqlite3_malloc] and the pragma may attempt to free that memory
4561 ** using [sqlite3_free].
4562 ** Hence, if this variable is modified directly, either it should be
4563 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
4564 ** or else the use of the [data_store_directory pragma] should be avoided.
4565 */
4566 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
4567
4568 /*
4569 ** CAPI3REF: Test For Auto-Commit Mode
4570 ** KEYWORDS: {autocommit mode}
4571 **
4572 ** ^The sqlite3_get_autocommit() interface returns non-zero or
4573 ** zero if the given database connection is or is not in autocommit mode,
4574 ** respectively. ^Autocommit mode is on by default.
4575 ** ^Autocommit mode is disabled by a [BEGIN] statement.
4576 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
4577 **
4578 ** If certain kinds of errors occur on a statement within a multi-statement
4579 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
4580 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
4581 ** transaction might be rolled back automatically. The only way to
4582 ** find out whether SQLite automatically rolled back the transaction after
4583 ** an error is to use this function.
4584 **
4585 ** If another thread changes the autocommit status of the database
4586 ** connection while this routine is running, then the return value
4587 ** is undefined.
4588 */
4589 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
4590
4591 /*
4592 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
4593 **
4594 ** ^The sqlite3_db_handle interface returns the [database connection] handle
4595 ** to which a [prepared statement] belongs. ^The [database connection]
4596 ** returned by sqlite3_db_handle is the same [database connection]
4597 ** that was the first argument
4598 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
4599 ** create the statement in the first place.
4600 */
4601 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
4602
4603 /*
4604 ** CAPI3REF: Return The Filename For A Database Connection
4605 **
4606 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
4607 ** associated with database N of connection D. ^The main database file
4608 ** has the name "main". If there is no attached database N on the database
4609 ** connection D, or if database N is a temporary or in-memory database, then
4610 ** a NULL pointer is returned.
4611 **
4612 ** ^The filename returned by this function is the output of the
4613 ** xFullPathname method of the [VFS]. ^In other words, the filename
4614 ** will be an absolute pathname, even if the filename used
4615 ** to open the database originally was a URI or relative pathname.
4616 */
4617 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
4618
4619 /*
4620 ** CAPI3REF: Determine if a database is read-only
4621 **
4622 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
4623 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
4624 ** the name of a database on connection D.
4625 */
4626 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
4627
4628 /*
4629 ** CAPI3REF: Find the next prepared statement
4630 **
4631 ** ^This interface returns a pointer to the next [prepared statement] after
4632 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
4633 ** then this interface returns a pointer to the first prepared statement
4634 ** associated with the database connection pDb. ^If no prepared statement
4635 ** satisfies the conditions of this routine, it returns NULL.
4636 **
4637 ** The [database connection] pointer D in a call to
4638 ** [sqlite3_next_stmt(D,S)] must refer to an open database
4639 ** connection and in particular must not be a NULL pointer.
4640 */
4641 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
4642
4643 /*
4644 ** CAPI3REF: Commit And Rollback Notification Callbacks
4645 **
4646 ** ^The sqlite3_commit_hook() interface registers a callback
4647 ** function to be invoked whenever a transaction is [COMMIT | committed].
4648 ** ^Any callback set by a previous call to sqlite3_commit_hook()
4649 ** for the same database connection is overridden.
4650 ** ^The sqlite3_rollback_hook() interface registers a callback
4651 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
4652 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
4653 ** for the same database connection is overridden.
4654 ** ^The pArg argument is passed through to the callback.
4655 ** ^If the callback on a commit hook function returns non-zero,
4656 ** then the commit is converted into a rollback.
4657 **
4658 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
4659 ** return the P argument from the previous call of the same function
4660 ** on the same [database connection] D, or NULL for
4661 ** the first call for each function on D.
4662 **
4663 ** The commit and rollback hook callbacks are not reentrant.
4664 ** The callback implementation must not do anything that will modify
4665 ** the database connection that invoked the callback. Any actions
4666 ** to modify the database connection must be deferred until after the
4667 ** completion of the [sqlite3_step()] call that triggered the commit
4668 ** or rollback hook in the first place.
4669 ** Note that running any other SQL statements, including SELECT statements,
4670 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
4671 ** the database connections for the meaning of "modify" in this paragraph.
4672 **
4673 ** ^Registering a NULL function disables the callback.
4674 **
4675 ** ^When the commit hook callback routine returns zero, the [COMMIT]
4676 ** operation is allowed to continue normally. ^If the commit hook
4677 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
4678 ** ^The rollback hook is invoked on a rollback that results from a commit
4679 ** hook returning non-zero, just as it would be with any other rollback.
4680 **
4681 ** ^For the purposes of this API, a transaction is said to have been
4682 ** rolled back if an explicit "ROLLBACK" statement is executed, or
4683 ** an error or constraint causes an implicit rollback to occur.
4684 ** ^The rollback callback is not invoked if a transaction is
4685 ** automatically rolled back because the database connection is closed.
4686 **
4687 ** See also the [sqlite3_update_hook()] interface.
4688 */
4689 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
4690 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
4691
4692 /*
4693 ** CAPI3REF: Data Change Notification Callbacks
4694 **
4695 ** ^The sqlite3_update_hook() interface registers a callback function
4696 ** with the [database connection] identified by the first argument
4697 ** to be invoked whenever a row is updated, inserted or deleted.
4698 ** ^Any callback set by a previous call to this function
4699 ** for the same database connection is overridden.
4700 **
4701 ** ^The second argument is a pointer to the function to invoke when a
4702 ** row is updated, inserted or deleted.
4703 ** ^The first argument to the callback is a copy of the third argument
4704 ** to sqlite3_update_hook().
4705 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
4706 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
4707 ** to be invoked.
4708 ** ^The third and fourth arguments to the callback contain pointers to the
4709 ** database and table name containing the affected row.
4710 ** ^The final callback parameter is the [rowid] of the row.
4711 ** ^In the case of an update, this is the [rowid] after the update takes place.
4712 **
4713 ** ^(The update hook is not invoked when internal system tables are
4714 ** modified (i.e. sqlite_master and sqlite_sequence).)^
4715 **
4716 ** ^In the current implementation, the update hook
4717 ** is not invoked when duplication rows are deleted because of an
4718 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
4719 ** invoked when rows are deleted using the [truncate optimization].
4720 ** The exceptions defined in this paragraph might change in a future
4721 ** release of SQLite.
4722 **
4723 ** The update hook implementation must not do anything that will modify
4724 ** the database connection that invoked the update hook. Any actions
4725 ** to modify the database connection must be deferred until after the
4726 ** completion of the [sqlite3_step()] call that triggered the update hook.
4727 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
4728 ** database connections for the meaning of "modify" in this paragraph.
4729 **
4730 ** ^The sqlite3_update_hook(D,C,P) function
4731 ** returns the P argument from the previous call
4732 ** on the same [database connection] D, or NULL for
4733 ** the first call on D.
4734 **
4735 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
4736 ** interfaces.
4737 */
4738 SQLITE_API void *sqlite3_update_hook(
4739 sqlite3*,
4740 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
4741 void*
4742 );
4743
4744 /*
4745 ** CAPI3REF: Enable Or Disable Shared Pager Cache
4746 **
4747 ** ^(This routine enables or disables the sharing of the database cache
4748 ** and schema data structures between [database connection | connections]
4749 ** to the same database. Sharing is enabled if the argument is true
4750 ** and disabled if the argument is false.)^
4751 **
4752 ** ^Cache sharing is enabled and disabled for an entire process.
4753 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
4754 ** sharing was enabled or disabled for each thread separately.
4755 **
4756 ** ^(The cache sharing mode set by this interface effects all subsequent
4757 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
4758 ** Existing database connections continue use the sharing mode
4759 ** that was in effect at the time they were opened.)^
4760 **
4761 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
4762 ** successfully. An [error code] is returned otherwise.)^
4763 **
4764 ** ^Shared cache is disabled by default. But this might change in
4765 ** future releases of SQLite. Applications that care about shared
4766 ** cache setting should set it explicitly.
4767 **
4768 ** This interface is threadsafe on processors where writing a
4769 ** 32-bit integer is atomic.
4770 **
4771 ** See Also: [SQLite Shared-Cache Mode]
4772 */
4773 SQLITE_API int sqlite3_enable_shared_cache(int);
4774
4775 /*
4776 ** CAPI3REF: Attempt To Free Heap Memory
4777 **
4778 ** ^The sqlite3_release_memory() interface attempts to free N bytes
4779 ** of heap memory by deallocating non-essential memory allocations
4780 ** held by the database library. Memory used to cache database
4781 ** pages to improve performance is an example of non-essential memory.
4782 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
4783 ** which might be more or less than the amount requested.
4784 ** ^The sqlite3_release_memory() routine is a no-op returning zero
4785 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4786 **
4787 ** See also: [sqlite3_db_release_memory()]
4788 */
4789 SQLITE_API int sqlite3_release_memory(int);
4790
4791 /*
4792 ** CAPI3REF: Free Memory Used By A Database Connection
4793 **
4794 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
4795 ** memory as possible from database connection D. Unlike the
4796 ** [sqlite3_release_memory()] interface, this interface is effect even
4797 ** when then [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
4798 ** omitted.
4799 **
4800 ** See also: [sqlite3_release_memory()]
4801 */
4802 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
4803
4804 /*
4805 ** CAPI3REF: Impose A Limit On Heap Size
4806 **
4807 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
4808 ** soft limit on the amount of heap memory that may be allocated by SQLite.
4809 ** ^SQLite strives to keep heap memory utilization below the soft heap
4810 ** limit by reducing the number of pages held in the page cache
4811 ** as heap memory usages approaches the limit.
4812 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
4813 ** below the limit, it will exceed the limit rather than generate
4814 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
4815 ** is advisory only.
4816 **
4817 ** ^The return value from sqlite3_soft_heap_limit64() is the size of
4818 ** the soft heap limit prior to the call, or negative in the case of an
4819 ** error. ^If the argument N is negative
4820 ** then no change is made to the soft heap limit. Hence, the current
4821 ** size of the soft heap limit can be determined by invoking
4822 ** sqlite3_soft_heap_limit64() with a negative argument.
4823 **
4824 ** ^If the argument N is zero then the soft heap limit is disabled.
4825 **
4826 ** ^(The soft heap limit is not enforced in the current implementation
4827 ** if one or more of following conditions are true:
4828 **
4829 ** <ul>
4830 ** <li> The soft heap limit is set to zero.
4831 ** <li> Memory accounting is disabled using a combination of the
4832 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
4833 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
4834 ** <li> An alternative page cache implementation is specified using
4835 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
4836 ** <li> The page cache allocates from its own memory pool supplied
4837 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
4838 ** from the heap.
4839 ** </ul>)^
4840 **
4841 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
4842 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
4843 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
4844 ** the soft heap limit is enforced on every memory allocation. Without
4845 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
4846 ** when memory is allocated by the page cache. Testing suggests that because
4847 ** the page cache is the predominate memory user in SQLite, most
4848 ** applications will achieve adequate soft heap limit enforcement without
4849 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
4850 **
4851 ** The circumstances under which SQLite will enforce the soft heap limit may
4852 ** changes in future releases of SQLite.
4853 */
4854 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
4855
4856 /*
4857 ** CAPI3REF: Deprecated Soft Heap Limit Interface
4858 ** DEPRECATED
4859 **
4860 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
4861 ** interface. This routine is provided for historical compatibility
4862 ** only. All new applications should use the
4863 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
4864 */
4865 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
4866
4867
4868 /*
4869 ** CAPI3REF: Extract Metadata About A Column Of A Table
4870 **
4871 ** ^This routine returns metadata about a specific column of a specific
4872 ** database table accessible using the [database connection] handle
4873 ** passed as the first function argument.
4874 **
4875 ** ^The column is identified by the second, third and fourth parameters to
4876 ** this function. ^The second parameter is either the name of the database
4877 ** (i.e. "main", "temp", or an attached database) containing the specified
4878 ** table or NULL. ^If it is NULL, then all attached databases are searched
4879 ** for the table using the same algorithm used by the database engine to
4880 ** resolve unqualified table references.
4881 **
4882 ** ^The third and fourth parameters to this function are the table and column
4883 ** name of the desired column, respectively. Neither of these parameters
4884 ** may be NULL.
4885 **
4886 ** ^Metadata is returned by writing to the memory locations passed as the 5th
4887 ** and subsequent parameters to this function. ^Any of these arguments may be
4888 ** NULL, in which case the corresponding element of metadata is omitted.
4889 **
4890 ** ^(<blockquote>
4891 ** <table border="1">
4892 ** <tr><th> Parameter <th> Output<br>Type <th> Description
4893 **
4894 ** <tr><td> 5th <td> const char* <td> Data type
4895 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
4896 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
4897 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
4898 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
4899 ** </table>
4900 ** </blockquote>)^
4901 **
4902 ** ^The memory pointed to by the character pointers returned for the
4903 ** declaration type and collation sequence is valid only until the next
4904 ** call to any SQLite API function.
4905 **
4906 ** ^If the specified table is actually a view, an [error code] is returned.
4907 **
4908 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an
4909 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
4910 ** parameters are set for the explicitly declared column. ^(If there is no
4911 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output
4912 ** parameters are set as follows:
4913 **
4914 ** <pre>
4915 ** data type: "INTEGER"
4916 ** collation sequence: "BINARY"
4917 ** not null: 0
4918 ** primary key: 1
4919 ** auto increment: 0
4920 ** </pre>)^
4921 **
4922 ** ^(This function may load one or more schemas from database files. If an
4923 ** error occurs during this process, or if the requested table or column
4924 ** cannot be found, an [error code] is returned and an error message left
4925 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
4926 **
4927 ** ^This API is only available if the library was compiled with the
4928 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
4929 */
4930 SQLITE_API int sqlite3_table_column_metadata(
4931 sqlite3 *db, /* Connection handle */
4932 const char *zDbName, /* Database name or NULL */
4933 const char *zTableName, /* Table name */
4934 const char *zColumnName, /* Column name */
4935 char const **pzDataType, /* OUTPUT: Declared data type */
4936 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
4937 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
4938 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
4939 int *pAutoinc /* OUTPUT: True if column is auto-increment */
4940 );
4941
4942 /*
4943 ** CAPI3REF: Load An Extension
4944 **
4945 ** ^This interface loads an SQLite extension library from the named file.
4946 **
4947 ** ^The sqlite3_load_extension() interface attempts to load an
4948 ** SQLite extension library contained in the file zFile.
4949 **
4950 ** ^The entry point is zProc.
4951 ** ^zProc may be 0, in which case the name of the entry point
4952 ** defaults to "sqlite3_extension_init".
4953 ** ^The sqlite3_load_extension() interface returns
4954 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
4955 ** ^If an error occurs and pzErrMsg is not 0, then the
4956 ** [sqlite3_load_extension()] interface shall attempt to
4957 ** fill *pzErrMsg with error message text stored in memory
4958 ** obtained from [sqlite3_malloc()]. The calling function
4959 ** should free this memory by calling [sqlite3_free()].
4960 **
4961 ** ^Extension loading must be enabled using
4962 ** [sqlite3_enable_load_extension()] prior to calling this API,
4963 ** otherwise an error will be returned.
4964 **
4965 ** See also the [load_extension() SQL function].
4966 */
4967 SQLITE_API int sqlite3_load_extension(
4968 sqlite3 *db, /* Load the extension into this database connection */
4969 const char *zFile, /* Name of the shared library containing extension */
4970 const char *zProc, /* Entry point. Derived from zFile if 0 */
4971 char **pzErrMsg /* Put error message here if not 0 */
4972 );
4973
4974 /*
4975 ** CAPI3REF: Enable Or Disable Extension Loading
4976 **
4977 ** ^So as not to open security holes in older applications that are
4978 ** unprepared to deal with extension loading, and as a means of disabling
4979 ** extension loading while evaluating user-entered SQL, the following API
4980 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
4981 **
4982 ** ^Extension loading is off by default. See ticket #1863.
4983 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
4984 ** to turn extension loading on and call it with onoff==0 to turn
4985 ** it back off again.
4986 */
4987 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
4988
4989 /*
4990 ** CAPI3REF: Automatically Load Statically Linked Extensions
4991 **
4992 ** ^This interface causes the xEntryPoint() function to be invoked for
4993 ** each new [database connection] that is created. The idea here is that
4994 ** xEntryPoint() is the entry point for a statically linked SQLite extension
4995 ** that is to be automatically loaded into all new database connections.
4996 **
4997 ** ^(Even though the function prototype shows that xEntryPoint() takes
4998 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
4999 ** arguments and expects and integer result as if the signature of the
5000 ** entry point where as follows:
5001 **
5002 ** <blockquote><pre>
5003 ** &nbsp; int xEntryPoint(
5004 ** &nbsp; sqlite3 *db,
5005 ** &nbsp; const char **pzErrMsg,
5006 ** &nbsp; const struct sqlite3_api_routines *pThunk
5007 ** &nbsp; );
5008 ** </pre></blockquote>)^
5009 **
5010 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5011 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5012 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5013 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5014 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5015 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5016 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5017 **
5018 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5019 ** on the list of automatic extensions is a harmless no-op. ^No entry point
5020 ** will be called more than once for each database connection that is opened.
5021 **
5022 ** See also: [sqlite3_reset_auto_extension()].
5023 */
5024 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void));
5025
5026 /*
5027 ** CAPI3REF: Reset Automatic Extension Loading
5028 **
5029 ** ^This interface disables all automatic extensions previously
5030 ** registered using [sqlite3_auto_extension()].
5031 */
5032 SQLITE_API void sqlite3_reset_auto_extension(void);
5033
5034 /*
5035 ** The interface to the virtual-table mechanism is currently considered
5036 ** to be experimental. The interface might change in incompatible ways.
5037 ** If this is a problem for you, do not use the interface at this time.
5038 **
5039 ** When the virtual-table mechanism stabilizes, we will declare the
5040 ** interface fixed, support it indefinitely, and remove this comment.
5041 */
5042
5043 /*
5044 ** Structures used by the virtual table interface
5045 */
5046 typedef struct sqlite3_vtab sqlite3_vtab;
5047 typedef struct sqlite3_index_info sqlite3_index_info;
5048 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5049 typedef struct sqlite3_module sqlite3_module;
5050
5051 /*
5052 ** CAPI3REF: Virtual Table Object
5053 ** KEYWORDS: sqlite3_module {virtual table module}
5054 **
5055 ** This structure, sometimes called a "virtual table module",
5056 ** defines the implementation of a [virtual tables].
5057 ** This structure consists mostly of methods for the module.
5058 **
5059 ** ^A virtual table module is created by filling in a persistent
5060 ** instance of this structure and passing a pointer to that instance
5061 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5062 ** ^The registration remains valid until it is replaced by a different
5063 ** module or until the [database connection] closes. The content
5064 ** of this structure must not change while it is registered with
5065 ** any database connection.
5066 */
5067 struct sqlite3_module {
5068 int iVersion;
5069 int (*xCreate)(sqlite3*, void *pAux,
5070 int argc, const char *const*argv,
5071 sqlite3_vtab **ppVTab, char**);
5072 int (*xConnect)(sqlite3*, void *pAux,
5073 int argc, const char *const*argv,
5074 sqlite3_vtab **ppVTab, char**);
5075 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5076 int (*xDisconnect)(sqlite3_vtab *pVTab);
5077 int (*xDestroy)(sqlite3_vtab *pVTab);
5078 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5079 int (*xClose)(sqlite3_vtab_cursor*);
5080 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5081 int argc, sqlite3_value **argv);
5082 int (*xNext)(sqlite3_vtab_cursor*);
5083 int (*xEof)(sqlite3_vtab_cursor*);
5084 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5085 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5086 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5087 int (*xBegin)(sqlite3_vtab *pVTab);
5088 int (*xSync)(sqlite3_vtab *pVTab);
5089 int (*xCommit)(sqlite3_vtab *pVTab);
5090 int (*xRollback)(sqlite3_vtab *pVTab);
5091 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5092 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5093 void **ppArg);
5094 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5095 /* The methods above are in version 1 of the sqlite_module object. Those
5096 ** below are for version 2 and greater. */
5097 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5098 int (*xRelease)(sqlite3_vtab *pVTab, int);
5099 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5100 };
5101
5102 /*
5103 ** CAPI3REF: Virtual Table Indexing Information
5104 ** KEYWORDS: sqlite3_index_info
5105 **
5106 ** The sqlite3_index_info structure and its substructures is used as part
5107 ** of the [virtual table] interface to
5108 ** pass information into and receive the reply from the [xBestIndex]
5109 ** method of a [virtual table module]. The fields under **Inputs** are the
5110 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
5111 ** results into the **Outputs** fields.
5112 **
5113 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
5114 **
5115 ** <blockquote>column OP expr</blockquote>
5116 **
5117 ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
5118 ** stored in aConstraint[].op using one of the
5119 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5120 ** ^(The index of the column is stored in
5121 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
5122 ** expr on the right-hand side can be evaluated (and thus the constraint
5123 ** is usable) and false if it cannot.)^
5124 **
5125 ** ^The optimizer automatically inverts terms of the form "expr OP column"
5126 ** and makes other simplifications to the WHERE clause in an attempt to
5127 ** get as many WHERE clause terms into the form shown above as possible.
5128 ** ^The aConstraint[] array only reports WHERE clause terms that are
5129 ** relevant to the particular virtual table being queried.
5130 **
5131 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
5132 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
5133 **
5134 ** The [xBestIndex] method must fill aConstraintUsage[] with information
5135 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
5136 ** the right-hand side of the corresponding aConstraint[] is evaluated
5137 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
5138 ** is true, then the constraint is assumed to be fully handled by the
5139 ** virtual table and is not checked again by SQLite.)^
5140 **
5141 ** ^The idxNum and idxPtr values are recorded and passed into the
5142 ** [xFilter] method.
5143 ** ^[sqlite3_free()] is used to free idxPtr if and only if
5144 ** needToFreeIdxPtr is true.
5145 **
5146 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5147 ** the correct order to satisfy the ORDER BY clause so that no separate
5148 ** sorting step is required.
5149 **
5150 ** ^The estimatedCost value is an estimate of the cost of doing the
5151 ** particular lookup. A full scan of a table with N entries should have
5152 ** a cost of N. A binary search of a table of N entries should have a
5153 ** cost of approximately log(N).
5154 */
5155 struct sqlite3_index_info {
5156 /* Inputs */
5157 int nConstraint; /* Number of entries in aConstraint */
5158 struct sqlite3_index_constraint {
5159 int iColumn; /* Column on left-hand side of constraint */
5160 unsigned char op; /* Constraint operator */
5161 unsigned char usable; /* True if this constraint is usable */
5162 int iTermOffset; /* Used internally - xBestIndex should ignore */
5163 } *aConstraint; /* Table of WHERE clause constraints */
5164 int nOrderBy; /* Number of terms in the ORDER BY clause */
5165 struct sqlite3_index_orderby {
5166 int iColumn; /* Column number */
5167 unsigned char desc; /* True for DESC. False for ASC. */
5168 } *aOrderBy; /* The ORDER BY clause */
5169 /* Outputs */
5170 struct sqlite3_index_constraint_usage {
5171 int argvIndex; /* if >0, constraint is part of argv to xFilter */
5172 unsigned char omit; /* Do not code a test for this constraint */
5173 } *aConstraintUsage;
5174 int idxNum; /* Number used to identify the index */
5175 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5176 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5177 int orderByConsumed; /* True if output is already ordered */
5178 double estimatedCost; /* Estimated cost of using this index */
5179 };
5180
5181 /*
5182 ** CAPI3REF: Virtual Table Constraint Operator Codes
5183 **
5184 ** These macros defined the allowed values for the
5185 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
5186 ** an operator that is part of a constraint term in the wHERE clause of
5187 ** a query that uses a [virtual table].
5188 */
5189 #define SQLITE_INDEX_CONSTRAINT_EQ 2
5190 #define SQLITE_INDEX_CONSTRAINT_GT 4
5191 #define SQLITE_INDEX_CONSTRAINT_LE 8
5192 #define SQLITE_INDEX_CONSTRAINT_LT 16
5193 #define SQLITE_INDEX_CONSTRAINT_GE 32
5194 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
5195
5196 /*
5197 ** CAPI3REF: Register A Virtual Table Implementation
5198 **
5199 ** ^These routines are used to register a new [virtual table module] name.
5200 ** ^Module names must be registered before
5201 ** creating a new [virtual table] using the module and before using a
5202 ** preexisting [virtual table] for the module.
5203 **
5204 ** ^The module name is registered on the [database connection] specified
5205 ** by the first parameter. ^The name of the module is given by the
5206 ** second parameter. ^The third parameter is a pointer to
5207 ** the implementation of the [virtual table module]. ^The fourth
5208 ** parameter is an arbitrary client data pointer that is passed through
5209 ** into the [xCreate] and [xConnect] methods of the virtual table module
5210 ** when a new virtual table is be being created or reinitialized.
5211 **
5212 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5213 ** is a pointer to a destructor for the pClientData. ^SQLite will
5214 ** invoke the destructor function (if it is not NULL) when SQLite
5215 ** no longer needs the pClientData pointer. ^The destructor will also
5216 ** be invoked if the call to sqlite3_create_module_v2() fails.
5217 ** ^The sqlite3_create_module()
5218 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
5219 ** destructor.
5220 */
5221 SQLITE_API int sqlite3_create_module(
5222 sqlite3 *db, /* SQLite connection to register module with */
5223 const char *zName, /* Name of the module */
5224 const sqlite3_module *p, /* Methods for the module */
5225 void *pClientData /* Client data for xCreate/xConnect */
5226 );
5227 SQLITE_API int sqlite3_create_module_v2(
5228 sqlite3 *db, /* SQLite connection to register module with */
5229 const char *zName, /* Name of the module */
5230 const sqlite3_module *p, /* Methods for the module */
5231 void *pClientData, /* Client data for xCreate/xConnect */
5232 void(*xDestroy)(void*) /* Module destructor function */
5233 );
5234
5235 /*
5236 ** CAPI3REF: Virtual Table Instance Object
5237 ** KEYWORDS: sqlite3_vtab
5238 **
5239 ** Every [virtual table module] implementation uses a subclass
5240 ** of this object to describe a particular instance
5241 ** of the [virtual table]. Each subclass will
5242 ** be tailored to the specific needs of the module implementation.
5243 ** The purpose of this superclass is to define certain fields that are
5244 ** common to all module implementations.
5245 **
5246 ** ^Virtual tables methods can set an error message by assigning a
5247 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
5248 ** take care that any prior string is freed by a call to [sqlite3_free()]
5249 ** prior to assigning a new string to zErrMsg. ^After the error message
5250 ** is delivered up to the client application, the string will be automatically
5251 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5252 */
5253 struct sqlite3_vtab {
5254 const sqlite3_module *pModule; /* The module for this virtual table */
5255 int nRef; /* NO LONGER USED */
5256 char *zErrMsg; /* Error message from sqlite3_mprintf() */
5257 /* Virtual table implementations will typically add additional fields */
5258 };
5259
5260 /*
5261 ** CAPI3REF: Virtual Table Cursor Object
5262 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5263 **
5264 ** Every [virtual table module] implementation uses a subclass of the
5265 ** following structure to describe cursors that point into the
5266 ** [virtual table] and are used
5267 ** to loop through the virtual table. Cursors are created using the
5268 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5269 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
5270 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5271 ** of the module. Each module implementation will define
5272 ** the content of a cursor structure to suit its own needs.
5273 **
5274 ** This superclass exists in order to define fields of the cursor that
5275 ** are common to all implementations.
5276 */
5277 struct sqlite3_vtab_cursor {
5278 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
5279 /* Virtual table implementations will typically add additional fields */
5280 };
5281
5282 /*
5283 ** CAPI3REF: Declare The Schema Of A Virtual Table
5284 **
5285 ** ^The [xCreate] and [xConnect] methods of a
5286 ** [virtual table module] call this interface
5287 ** to declare the format (the names and datatypes of the columns) of
5288 ** the virtual tables they implement.
5289 */
5290 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5291
5292 /*
5293 ** CAPI3REF: Overload A Function For A Virtual Table
5294 **
5295 ** ^(Virtual tables can provide alternative implementations of functions
5296 ** using the [xFindFunction] method of the [virtual table module].
5297 ** But global versions of those functions
5298 ** must exist in order to be overloaded.)^
5299 **
5300 ** ^(This API makes sure a global version of a function with a particular
5301 ** name and number of parameters exists. If no such function exists
5302 ** before this API is called, a new function is created.)^ ^The implementation
5303 ** of the new function always causes an exception to be thrown. So
5304 ** the new function is not good for anything by itself. Its only
5305 ** purpose is to be a placeholder function that can be overloaded
5306 ** by a [virtual table].
5307 */
5308 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5309
5310 /*
5311 ** The interface to the virtual-table mechanism defined above (back up
5312 ** to a comment remarkably similar to this one) is currently considered
5313 ** to be experimental. The interface might change in incompatible ways.
5314 ** If this is a problem for you, do not use the interface at this time.
5315 **
5316 ** When the virtual-table mechanism stabilizes, we will declare the
5317 ** interface fixed, support it indefinitely, and remove this comment.
5318 */
5319
5320 /*
5321 ** CAPI3REF: A Handle To An Open BLOB
5322 ** KEYWORDS: {BLOB handle} {BLOB handles}
5323 **
5324 ** An instance of this object represents an open BLOB on which
5325 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5326 ** ^Objects of this type are created by [sqlite3_blob_open()]
5327 ** and destroyed by [sqlite3_blob_close()].
5328 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5329 ** can be used to read or write small subsections of the BLOB.
5330 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5331 */
5332 typedef struct sqlite3_blob sqlite3_blob;
5333
5334 /*
5335 ** CAPI3REF: Open A BLOB For Incremental I/O
5336 **
5337 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5338 ** in row iRow, column zColumn, table zTable in database zDb;
5339 ** in other words, the same BLOB that would be selected by:
5340 **
5341 ** <pre>
5342 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5343 ** </pre>)^
5344 **
5345 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
5346 ** and write access. ^If it is zero, the BLOB is opened for read access.
5347 ** ^It is not possible to open a column that is part of an index or primary
5348 ** key for writing. ^If [foreign key constraints] are enabled, it is
5349 ** not possible to open a column that is part of a [child key] for writing.
5350 **
5351 ** ^Note that the database name is not the filename that contains
5352 ** the database but rather the symbolic name of the database that
5353 ** appears after the AS keyword when the database is connected using [ATTACH].
5354 ** ^For the main database file, the database name is "main".
5355 ** ^For TEMP tables, the database name is "temp".
5356 **
5357 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
5358 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
5359 ** to be a null pointer.)^
5360 ** ^This function sets the [database connection] error code and message
5361 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
5362 ** functions. ^Note that the *ppBlob variable is always initialized in a
5363 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
5364 ** regardless of the success or failure of this routine.
5365 **
5366 ** ^(If the row that a BLOB handle points to is modified by an
5367 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
5368 ** then the BLOB handle is marked as "expired".
5369 ** This is true if any column of the row is changed, even a column
5370 ** other than the one the BLOB handle is open on.)^
5371 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
5372 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
5373 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
5374 ** rolled back by the expiration of the BLOB. Such changes will eventually
5375 ** commit if the transaction continues to completion.)^
5376 **
5377 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
5378 ** the opened blob. ^The size of a blob may not be changed by this
5379 ** interface. Use the [UPDATE] SQL command to change the size of a
5380 ** blob.
5381 **
5382 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
5383 ** and the built-in [zeroblob] SQL function can be used, if desired,
5384 ** to create an empty, zero-filled blob in which to read or write using
5385 ** this interface.
5386 **
5387 ** To avoid a resource leak, every open [BLOB handle] should eventually
5388 ** be released by a call to [sqlite3_blob_close()].
5389 */
5390 SQLITE_API int sqlite3_blob_open(
5391 sqlite3*,
5392 const char *zDb,
5393 const char *zTable,
5394 const char *zColumn,
5395 sqlite3_int64 iRow,
5396 int flags,
5397 sqlite3_blob **ppBlob
5398 );
5399
5400 /*
5401 ** CAPI3REF: Move a BLOB Handle to a New Row
5402 **
5403 ** ^This function is used to move an existing blob handle so that it points
5404 ** to a different row of the same database table. ^The new row is identified
5405 ** by the rowid value passed as the second argument. Only the row can be
5406 ** changed. ^The database, table and column on which the blob handle is open
5407 ** remain the same. Moving an existing blob handle to a new row can be
5408 ** faster than closing the existing handle and opening a new one.
5409 **
5410 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
5411 ** it must exist and there must be either a blob or text value stored in
5412 ** the nominated column.)^ ^If the new row is not present in the table, or if
5413 ** it does not contain a blob or text value, or if another error occurs, an
5414 ** SQLite error code is returned and the blob handle is considered aborted.
5415 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
5416 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
5417 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
5418 ** always returns zero.
5419 **
5420 ** ^This function sets the database handle error code and message.
5421 */
5422 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
5423
5424 /*
5425 ** CAPI3REF: Close A BLOB Handle
5426 **
5427 ** ^Closes an open [BLOB handle].
5428 **
5429 ** ^Closing a BLOB shall cause the current transaction to commit
5430 ** if there are no other BLOBs, no pending prepared statements, and the
5431 ** database connection is in [autocommit mode].
5432 ** ^If any writes were made to the BLOB, they might be held in cache
5433 ** until the close operation if they will fit.
5434 **
5435 ** ^(Closing the BLOB often forces the changes
5436 ** out to disk and so if any I/O errors occur, they will likely occur
5437 ** at the time when the BLOB is closed. Any errors that occur during
5438 ** closing are reported as a non-zero return value.)^
5439 **
5440 ** ^(The BLOB is closed unconditionally. Even if this routine returns
5441 ** an error code, the BLOB is still closed.)^
5442 **
5443 ** ^Calling this routine with a null pointer (such as would be returned
5444 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.
5445 */
5446 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
5447
5448 /*
5449 ** CAPI3REF: Return The Size Of An Open BLOB
5450 **
5451 ** ^Returns the size in bytes of the BLOB accessible via the
5452 ** successfully opened [BLOB handle] in its only argument. ^The
5453 ** incremental blob I/O routines can only read or overwriting existing
5454 ** blob content; they cannot change the size of a blob.
5455 **
5456 ** This routine only works on a [BLOB handle] which has been created
5457 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5458 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5459 ** to this routine results in undefined and probably undesirable behavior.
5460 */
5461 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
5462
5463 /*
5464 ** CAPI3REF: Read Data From A BLOB Incrementally
5465 **
5466 ** ^(This function is used to read data from an open [BLOB handle] into a
5467 ** caller-supplied buffer. N bytes of data are copied into buffer Z
5468 ** from the open BLOB, starting at offset iOffset.)^
5469 **
5470 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5471 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
5472 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
5473 ** ^The size of the blob (and hence the maximum value of N+iOffset)
5474 ** can be determined using the [sqlite3_blob_bytes()] interface.
5475 **
5476 ** ^An attempt to read from an expired [BLOB handle] fails with an
5477 ** error code of [SQLITE_ABORT].
5478 **
5479 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
5480 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5481 **
5482 ** This routine only works on a [BLOB handle] which has been created
5483 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5484 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5485 ** to this routine results in undefined and probably undesirable behavior.
5486 **
5487 ** See also: [sqlite3_blob_write()].
5488 */
5489 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
5490
5491 /*
5492 ** CAPI3REF: Write Data Into A BLOB Incrementally
5493 **
5494 ** ^This function is used to write data into an open [BLOB handle] from a
5495 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
5496 ** into the open BLOB, starting at offset iOffset.
5497 **
5498 ** ^If the [BLOB handle] passed as the first argument was not opened for
5499 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
5500 ** this function returns [SQLITE_READONLY].
5501 **
5502 ** ^This function may only modify the contents of the BLOB; it is
5503 ** not possible to increase the size of a BLOB using this API.
5504 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
5505 ** [SQLITE_ERROR] is returned and no data is written. ^If N is
5506 ** less than zero [SQLITE_ERROR] is returned and no data is written.
5507 ** The size of the BLOB (and hence the maximum value of N+iOffset)
5508 ** can be determined using the [sqlite3_blob_bytes()] interface.
5509 **
5510 ** ^An attempt to write to an expired [BLOB handle] fails with an
5511 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
5512 ** before the [BLOB handle] expired are not rolled back by the
5513 ** expiration of the handle, though of course those changes might
5514 ** have been overwritten by the statement that expired the BLOB handle
5515 ** or by other independent statements.
5516 **
5517 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
5518 ** Otherwise, an [error code] or an [extended error code] is returned.)^
5519 **
5520 ** This routine only works on a [BLOB handle] which has been created
5521 ** by a prior successful call to [sqlite3_blob_open()] and which has not
5522 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
5523 ** to this routine results in undefined and probably undesirable behavior.
5524 **
5525 ** See also: [sqlite3_blob_read()].
5526 */
5527 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
5528
5529 /*
5530 ** CAPI3REF: Virtual File System Objects
5531 **
5532 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
5533 ** that SQLite uses to interact
5534 ** with the underlying operating system. Most SQLite builds come with a
5535 ** single default VFS that is appropriate for the host computer.
5536 ** New VFSes can be registered and existing VFSes can be unregistered.
5537 ** The following interfaces are provided.
5538 **
5539 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
5540 ** ^Names are case sensitive.
5541 ** ^Names are zero-terminated UTF-8 strings.
5542 ** ^If there is no match, a NULL pointer is returned.
5543 ** ^If zVfsName is NULL then the default VFS is returned.
5544 **
5545 ** ^New VFSes are registered with sqlite3_vfs_register().
5546 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
5547 ** ^The same VFS can be registered multiple times without injury.
5548 ** ^To make an existing VFS into the default VFS, register it again
5549 ** with the makeDflt flag set. If two different VFSes with the
5550 ** same name are registered, the behavior is undefined. If a
5551 ** VFS is registered with a name that is NULL or an empty string,
5552 ** then the behavior is undefined.
5553 **
5554 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
5555 ** ^(If the default VFS is unregistered, another VFS is chosen as
5556 ** the default. The choice for the new VFS is arbitrary.)^
5557 */
5558 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5559 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5560 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
5561
5562 /*
5563 ** CAPI3REF: Mutexes
5564 **
5565 ** The SQLite core uses these routines for thread
5566 ** synchronization. Though they are intended for internal
5567 ** use by SQLite, code that links against SQLite is
5568 ** permitted to use any of these routines.
5569 **
5570 ** The SQLite source code contains multiple implementations
5571 ** of these mutex routines. An appropriate implementation
5572 ** is selected automatically at compile-time. ^(The following
5573 ** implementations are available in the SQLite core:
5574 **
5575 ** <ul>
5576 ** <li> SQLITE_MUTEX_PTHREADS
5577 ** <li> SQLITE_MUTEX_W32
5578 ** <li> SQLITE_MUTEX_NOOP
5579 ** </ul>)^
5580 **
5581 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
5582 ** that does no real locking and is appropriate for use in
5583 ** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and
5584 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
5585 ** and Windows.
5586 **
5587 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
5588 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
5589 ** implementation is included with the library. In this case the
5590 ** application must supply a custom mutex implementation using the
5591 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
5592 ** before calling sqlite3_initialize() or any other public sqlite3_
5593 ** function that calls sqlite3_initialize().)^
5594 **
5595 ** ^The sqlite3_mutex_alloc() routine allocates a new
5596 ** mutex and returns a pointer to it. ^If it returns NULL
5597 ** that means that a mutex could not be allocated. ^SQLite
5598 ** will unwind its stack and return an error. ^(The argument
5599 ** to sqlite3_mutex_alloc() is one of these integer constants:
5600 **
5601 ** <ul>
5602 ** <li> SQLITE_MUTEX_FAST
5603 ** <li> SQLITE_MUTEX_RECURSIVE
5604 ** <li> SQLITE_MUTEX_STATIC_MASTER
5605 ** <li> SQLITE_MUTEX_STATIC_MEM
5606 ** <li> SQLITE_MUTEX_STATIC_MEM2
5607 ** <li> SQLITE_MUTEX_STATIC_PRNG
5608 ** <li> SQLITE_MUTEX_STATIC_LRU
5609 ** <li> SQLITE_MUTEX_STATIC_LRU2
5610 ** </ul>)^
5611 **
5612 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
5613 ** cause sqlite3_mutex_alloc() to create
5614 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
5615 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
5616 ** The mutex implementation does not need to make a distinction
5617 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
5618 ** not want to. ^SQLite will only request a recursive mutex in
5619 ** cases where it really needs one. ^If a faster non-recursive mutex
5620 ** implementation is available on the host platform, the mutex subsystem
5621 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
5622 **
5623 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
5624 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
5625 ** a pointer to a static preexisting mutex. ^Six static mutexes are
5626 ** used by the current version of SQLite. Future versions of SQLite
5627 ** may add additional static mutexes. Static mutexes are for internal
5628 ** use by SQLite only. Applications that use SQLite mutexes should
5629 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
5630 ** SQLITE_MUTEX_RECURSIVE.
5631 **
5632 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
5633 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
5634 ** returns a different mutex on every call. ^But for the static
5635 ** mutex types, the same mutex is returned on every call that has
5636 ** the same type number.
5637 **
5638 ** ^The sqlite3_mutex_free() routine deallocates a previously
5639 ** allocated dynamic mutex. ^SQLite is careful to deallocate every
5640 ** dynamic mutex that it allocates. The dynamic mutexes must not be in
5641 ** use when they are deallocated. Attempting to deallocate a static
5642 ** mutex results in undefined behavior. ^SQLite never deallocates
5643 ** a static mutex.
5644 **
5645 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
5646 ** to enter a mutex. ^If another thread is already within the mutex,
5647 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
5648 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
5649 ** upon successful entry. ^(Mutexes created using
5650 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
5651 ** In such cases the,
5652 ** mutex must be exited an equal number of times before another thread
5653 ** can enter.)^ ^(If the same thread tries to enter any other
5654 ** kind of mutex more than once, the behavior is undefined.
5655 ** SQLite will never exhibit
5656 ** such behavior in its own use of mutexes.)^
5657 **
5658 ** ^(Some systems (for example, Windows 95) do not support the operation
5659 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
5660 ** will always return SQLITE_BUSY. The SQLite core only ever uses
5661 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
5662 **
5663 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
5664 ** previously entered by the same thread. ^(The behavior
5665 ** is undefined if the mutex is not currently entered by the
5666 ** calling thread or is not currently allocated. SQLite will
5667 ** never do either.)^
5668 **
5669 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
5670 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines
5671 ** behave as no-ops.
5672 **
5673 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
5674 */
5675 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
5676 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
5677 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
5678 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
5679 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
5680
5681 /*
5682 ** CAPI3REF: Mutex Methods Object
5683 **
5684 ** An instance of this structure defines the low-level routines
5685 ** used to allocate and use mutexes.
5686 **
5687 ** Usually, the default mutex implementations provided by SQLite are
5688 ** sufficient, however the user has the option of substituting a custom
5689 ** implementation for specialized deployments or systems for which SQLite
5690 ** does not provide a suitable implementation. In this case, the user
5691 ** creates and populates an instance of this structure to pass
5692 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
5693 ** Additionally, an instance of this structure can be used as an
5694 ** output variable when querying the system for the current mutex
5695 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
5696 **
5697 ** ^The xMutexInit method defined by this structure is invoked as
5698 ** part of system initialization by the sqlite3_initialize() function.
5699 ** ^The xMutexInit routine is called by SQLite exactly once for each
5700 ** effective call to [sqlite3_initialize()].
5701 **
5702 ** ^The xMutexEnd method defined by this structure is invoked as
5703 ** part of system shutdown by the sqlite3_shutdown() function. The
5704 ** implementation of this method is expected to release all outstanding
5705 ** resources obtained by the mutex methods implementation, especially
5706 ** those obtained by the xMutexInit method. ^The xMutexEnd()
5707 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
5708 **
5709 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
5710 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
5711 ** xMutexNotheld) implement the following interfaces (respectively):
5712 **
5713 ** <ul>
5714 ** <li> [sqlite3_mutex_alloc()] </li>
5715 ** <li> [sqlite3_mutex_free()] </li>
5716 ** <li> [sqlite3_mutex_enter()] </li>
5717 ** <li> [sqlite3_mutex_try()] </li>
5718 ** <li> [sqlite3_mutex_leave()] </li>
5719 ** <li> [sqlite3_mutex_held()] </li>
5720 ** <li> [sqlite3_mutex_notheld()] </li>
5721 ** </ul>)^
5722 **
5723 ** The only difference is that the public sqlite3_XXX functions enumerated
5724 ** above silently ignore any invocations that pass a NULL pointer instead
5725 ** of a valid mutex handle. The implementations of the methods defined
5726 ** by this structure are not required to handle this case, the results
5727 ** of passing a NULL pointer instead of a valid mutex handle are undefined
5728 ** (i.e. it is acceptable to provide an implementation that segfaults if
5729 ** it is passed a NULL pointer).
5730 **
5731 ** The xMutexInit() method must be threadsafe. ^It must be harmless to
5732 ** invoke xMutexInit() multiple times within the same process and without
5733 ** intervening calls to xMutexEnd(). Second and subsequent calls to
5734 ** xMutexInit() must be no-ops.
5735 **
5736 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
5737 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory
5738 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
5739 ** memory allocation for a fast or recursive mutex.
5740 **
5741 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
5742 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
5743 ** If xMutexInit fails in any way, it is expected to clean up after itself
5744 ** prior to returning.
5745 */
5746 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
5747 struct sqlite3_mutex_methods {
5748 int (*xMutexInit)(void);
5749 int (*xMutexEnd)(void);
5750 sqlite3_mutex *(*xMutexAlloc)(int);
5751 void (*xMutexFree)(sqlite3_mutex *);
5752 void (*xMutexEnter)(sqlite3_mutex *);
5753 int (*xMutexTry)(sqlite3_mutex *);
5754 void (*xMutexLeave)(sqlite3_mutex *);
5755 int (*xMutexHeld)(sqlite3_mutex *);
5756 int (*xMutexNotheld)(sqlite3_mutex *);
5757 };
5758
5759 /*
5760 ** CAPI3REF: Mutex Verification Routines
5761 **
5762 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
5763 ** are intended for use inside assert() statements. ^The SQLite core
5764 ** never uses these routines except inside an assert() and applications
5765 ** are advised to follow the lead of the core. ^The SQLite core only
5766 ** provides implementations for these routines when it is compiled
5767 ** with the SQLITE_DEBUG flag. ^External mutex implementations
5768 ** are only required to provide these routines if SQLITE_DEBUG is
5769 ** defined and if NDEBUG is not defined.
5770 **
5771 ** ^These routines should return true if the mutex in their argument
5772 ** is held or not held, respectively, by the calling thread.
5773 **
5774 ** ^The implementation is not required to provide versions of these
5775 ** routines that actually work. If the implementation does not provide working
5776 ** versions of these routines, it should at least provide stubs that always
5777 ** return true so that one does not get spurious assertion failures.
5778 **
5779 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
5780 ** the routine should return 1. This seems counter-intuitive since
5781 ** clearly the mutex cannot be held if it does not exist. But
5782 ** the reason the mutex does not exist is because the build is not
5783 ** using mutexes. And we do not want the assert() containing the
5784 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
5785 ** the appropriate thing to do. ^The sqlite3_mutex_notheld()
5786 ** interface should also return 1 when given a NULL pointer.
5787 */
5788 #ifndef NDEBUG
5789 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
5790 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
5791 #endif
5792
5793 /*
5794 ** CAPI3REF: Mutex Types
5795 **
5796 ** The [sqlite3_mutex_alloc()] interface takes a single argument
5797 ** which is one of these integer constants.
5798 **
5799 ** The set of static mutexes may change from one SQLite release to the
5800 ** next. Applications that override the built-in mutex logic must be
5801 ** prepared to accommodate additional static mutexes.
5802 */
5803 #define SQLITE_MUTEX_FAST 0
5804 #define SQLITE_MUTEX_RECURSIVE 1
5805 #define SQLITE_MUTEX_STATIC_MASTER 2
5806 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
5807 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
5808 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
5809 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
5810 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
5811 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
5812 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
5813
5814 /*
5815 ** CAPI3REF: Retrieve the mutex for a database connection
5816 **
5817 ** ^This interface returns a pointer the [sqlite3_mutex] object that
5818 ** serializes access to the [database connection] given in the argument
5819 ** when the [threading mode] is Serialized.
5820 ** ^If the [threading mode] is Single-thread or Multi-thread then this
5821 ** routine returns a NULL pointer.
5822 */
5823 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
5824
5825 /*
5826 ** CAPI3REF: Low-Level Control Of Database Files
5827 **
5828 ** ^The [sqlite3_file_control()] interface makes a direct call to the
5829 ** xFileControl method for the [sqlite3_io_methods] object associated
5830 ** with a particular database identified by the second argument. ^The
5831 ** name of the database is "main" for the main database or "temp" for the
5832 ** TEMP database, or the name that appears after the AS keyword for
5833 ** databases that are added using the [ATTACH] SQL command.
5834 ** ^A NULL pointer can be used in place of "main" to refer to the
5835 ** main database file.
5836 ** ^The third and fourth parameters to this routine
5837 ** are passed directly through to the second and third parameters of
5838 ** the xFileControl method. ^The return value of the xFileControl
5839 ** method becomes the return value of this routine.
5840 **
5841 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
5842 ** a pointer to the underlying [sqlite3_file] object to be written into
5843 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
5844 ** case is a short-circuit path which does not actually invoke the
5845 ** underlying sqlite3_io_methods.xFileControl method.
5846 **
5847 ** ^If the second parameter (zDbName) does not match the name of any
5848 ** open database file, then SQLITE_ERROR is returned. ^This error
5849 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
5850 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
5851 ** also return SQLITE_ERROR. There is no way to distinguish between
5852 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
5853 ** xFileControl method.
5854 **
5855 ** See also: [SQLITE_FCNTL_LOCKSTATE]
5856 */
5857 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
5858
5859 /*
5860 ** CAPI3REF: Testing Interface
5861 **
5862 ** ^The sqlite3_test_control() interface is used to read out internal
5863 ** state of SQLite and to inject faults into SQLite for testing
5864 ** purposes. ^The first parameter is an operation code that determines
5865 ** the number, meaning, and operation of all subsequent parameters.
5866 **
5867 ** This interface is not for use by applications. It exists solely
5868 ** for verifying the correct operation of the SQLite library. Depending
5869 ** on how the SQLite library is compiled, this interface might not exist.
5870 **
5871 ** The details of the operation codes, their meanings, the parameters
5872 ** they take, and what they do are all subject to change without notice.
5873 ** Unlike most of the SQLite API, this function is not guaranteed to
5874 ** operate consistently from one release to the next.
5875 */
5876 SQLITE_API int sqlite3_test_control(int op, ...);
5877
5878 /*
5879 ** CAPI3REF: Testing Interface Operation Codes
5880 **
5881 ** These constants are the valid operation code parameters used
5882 ** as the first argument to [sqlite3_test_control()].
5883 **
5884 ** These parameters and their meanings are subject to change
5885 ** without notice. These values are for testing purposes only.
5886 ** Applications should not use any of these parameters or the
5887 ** [sqlite3_test_control()] interface.
5888 */
5889 #define SQLITE_TESTCTRL_FIRST 5
5890 #define SQLITE_TESTCTRL_PRNG_SAVE 5
5891 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
5892 #define SQLITE_TESTCTRL_PRNG_RESET 7
5893 #define SQLITE_TESTCTRL_BITVEC_TEST 8
5894 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
5895 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
5896 #define SQLITE_TESTCTRL_PENDING_BYTE 11
5897 #define SQLITE_TESTCTRL_ASSERT 12
5898 #define SQLITE_TESTCTRL_ALWAYS 13
5899 #define SQLITE_TESTCTRL_RESERVE 14
5900 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
5901 #define SQLITE_TESTCTRL_ISKEYWORD 16
5902 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17
5903 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
5904 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19
5905 #define SQLITE_TESTCTRL_LAST 19
5906
5907 /*
5908 ** CAPI3REF: SQLite Runtime Status
5909 **
5910 ** ^This interface is used to retrieve runtime status information
5911 ** about the performance of SQLite, and optionally to reset various
5912 ** highwater marks. ^The first argument is an integer code for
5913 ** the specific parameter to measure. ^(Recognized integer codes
5914 ** are of the form [status parameters | SQLITE_STATUS_...].)^
5915 ** ^The current value of the parameter is returned into *pCurrent.
5916 ** ^The highest recorded value is returned in *pHighwater. ^If the
5917 ** resetFlag is true, then the highest record value is reset after
5918 ** *pHighwater is written. ^(Some parameters do not record the highest
5919 ** value. For those parameters
5920 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
5921 ** ^(Other parameters record only the highwater mark and not the current
5922 ** value. For these latter parameters nothing is written into *pCurrent.)^
5923 **
5924 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a
5925 ** non-zero [error code] on failure.
5926 **
5927 ** This routine is threadsafe but is not atomic. This routine can be
5928 ** called while other threads are running the same or different SQLite
5929 ** interfaces. However the values returned in *pCurrent and
5930 ** *pHighwater reflect the status of SQLite at different points in time
5931 ** and it is possible that another thread might change the parameter
5932 ** in between the times when *pCurrent and *pHighwater are written.
5933 **
5934 ** See also: [sqlite3_db_status()]
5935 */
5936 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
5937
5938
5939 /*
5940 ** CAPI3REF: Status Parameters
5941 ** KEYWORDS: {status parameters}
5942 **
5943 ** These integer constants designate various run-time status parameters
5944 ** that can be returned by [sqlite3_status()].
5945 **
5946 ** <dl>
5947 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
5948 ** <dd>This parameter is the current amount of memory checked out
5949 ** using [sqlite3_malloc()], either directly or indirectly. The
5950 ** figure includes calls made to [sqlite3_malloc()] by the application
5951 ** and internal memory usage by the SQLite library. Scratch memory
5952 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
5953 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
5954 ** this parameter. The amount returned is the sum of the allocation
5955 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
5956 **
5957 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
5958 ** <dd>This parameter records the largest memory allocation request
5959 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
5960 ** internal equivalents). Only the value returned in the
5961 ** *pHighwater parameter to [sqlite3_status()] is of interest.
5962 ** The value written into the *pCurrent parameter is undefined.</dd>)^
5963 **
5964 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
5965 ** <dd>This parameter records the number of separate memory allocations
5966 ** currently checked out.</dd>)^
5967 **
5968 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
5969 ** <dd>This parameter returns the number of pages used out of the
5970 ** [pagecache memory allocator] that was configured using
5971 ** [SQLITE_CONFIG_PAGECACHE]. The
5972 ** value returned is in pages, not in bytes.</dd>)^
5973 **
5974 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
5975 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
5976 ** <dd>This parameter returns the number of bytes of page cache
5977 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
5978 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
5979 ** returned value includes allocations that overflowed because they
5980 ** where too large (they were larger than the "sz" parameter to
5981 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
5982 ** no space was left in the page cache.</dd>)^
5983 **
5984 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
5985 ** <dd>This parameter records the largest memory allocation request
5986 ** handed to [pagecache memory allocator]. Only the value returned in the
5987 ** *pHighwater parameter to [sqlite3_status()] is of interest.
5988 ** The value written into the *pCurrent parameter is undefined.</dd>)^
5989 **
5990 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
5991 ** <dd>This parameter returns the number of allocations used out of the
5992 ** [scratch memory allocator] configured using
5993 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
5994 ** in bytes. Since a single thread may only have one scratch allocation
5995 ** outstanding at time, this parameter also reports the number of threads
5996 ** using scratch memory at the same time.</dd>)^
5997 **
5998 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
5999 ** <dd>This parameter returns the number of bytes of scratch memory
6000 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6001 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6002 ** returned include overflows because the requested allocation was too
6003 ** larger (that is, because the requested allocation was larger than the
6004 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6005 ** slots were available.
6006 ** </dd>)^
6007 **
6008 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6009 ** <dd>This parameter records the largest memory allocation request
6010 ** handed to [scratch memory allocator]. Only the value returned in the
6011 ** *pHighwater parameter to [sqlite3_status()] is of interest.
6012 ** The value written into the *pCurrent parameter is undefined.</dd>)^
6013 **
6014 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6015 ** <dd>This parameter records the deepest parser stack. It is only
6016 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6017 ** </dl>
6018 **
6019 ** New status parameters may be added from time to time.
6020 */
6021 #define SQLITE_STATUS_MEMORY_USED 0
6022 #define SQLITE_STATUS_PAGECACHE_USED 1
6023 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6024 #define SQLITE_STATUS_SCRATCH_USED 3
6025 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6026 #define SQLITE_STATUS_MALLOC_SIZE 5
6027 #define SQLITE_STATUS_PARSER_STACK 6
6028 #define SQLITE_STATUS_PAGECACHE_SIZE 7
6029 #define SQLITE_STATUS_SCRATCH_SIZE 8
6030 #define SQLITE_STATUS_MALLOC_COUNT 9
6031
6032 /*
6033 ** CAPI3REF: Database Connection Status
6034 **
6035 ** ^This interface is used to retrieve runtime status information
6036 ** about a single [database connection]. ^The first argument is the
6037 ** database connection object to be interrogated. ^The second argument
6038 ** is an integer constant, taken from the set of
6039 ** [SQLITE_DBSTATUS options], that
6040 ** determines the parameter to interrogate. The set of
6041 ** [SQLITE_DBSTATUS options] is likely
6042 ** to grow in future releases of SQLite.
6043 **
6044 ** ^The current value of the requested parameter is written into *pCur
6045 ** and the highest instantaneous value is written into *pHiwtr. ^If
6046 ** the resetFlg is true, then the highest instantaneous value is
6047 ** reset back down to the current value.
6048 **
6049 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6050 ** non-zero [error code] on failure.
6051 **
6052 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6053 */
6054 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6055
6056 /*
6057 ** CAPI3REF: Status Parameters for database connections
6058 ** KEYWORDS: {SQLITE_DBSTATUS options}