1 /* 2 ** 2001-09-15 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 supposed 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 ** Provide the ability to override linkage features of the interface. 47 */ 48 #ifndef SQLITE_EXTERN 49 # define SQLITE_EXTERN extern 50 #endif 51 #ifndef SQLITE_API 52 # define SQLITE_API 53 #endif 54 #ifndef SQLITE_CDECL 55 # define SQLITE_CDECL 56 #endif 57 #ifndef SQLITE_APICALL 58 # define SQLITE_APICALL 59 #endif 60 #ifndef SQLITE_STDCALL 61 # define SQLITE_STDCALL SQLITE_APICALL 62 #endif 63 #ifndef SQLITE_CALLBACK 64 # define SQLITE_CALLBACK 65 #endif 66 #ifndef SQLITE_SYSAPI 67 # define SQLITE_SYSAPI 68 #endif 69 70 /* 71 ** These no-op macros are used in front of interfaces to mark those 72 ** interfaces as either deprecated or experimental. New applications 73 ** should not use deprecated interfaces - they are supported for backwards 74 ** compatibility only. Application writers should be aware that 75 ** experimental interfaces are subject to change in point releases. 76 ** 77 ** These macros used to resolve to various kinds of compiler magic that 78 ** would generate warning messages when they were used. But that 79 ** compiler magic ended up generating such a flurry of bug reports 80 ** that we have taken it all out and gone back to using simple 81 ** noop macros. 82 */ 83 #define SQLITE_DEPRECATED 84 #define SQLITE_EXPERIMENTAL 85 86 /* 87 ** Ensure these symbols were not defined by some previous header file. 88 */ 89 #ifdef SQLITE_VERSION 90 # undef SQLITE_VERSION 91 #endif 92 #ifdef SQLITE_VERSION_NUMBER 93 # undef SQLITE_VERSION_NUMBER 94 #endif 95 96 /* 97 ** CAPI3REF: Compile-Time Library Version Numbers 98 ** 99 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100 ** evaluates to a string literal that is the SQLite version in the 101 ** format "X.Y.Z" where X is the major version number (always 3 for 102 ** SQLite3) and Y is the minor version number and Z is the release number.)^ 103 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105 ** numbers used in [SQLITE_VERSION].)^ 106 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107 ** be larger than the release from which it is derived. Either Y will 108 ** be held constant and Z will be incremented or else Y will be incremented 109 ** and Z will be reset to zero. 110 ** 111 ** Since [version 3.6.18] ([dateof:3.6.18]), 112 ** SQLite source code has been stored in the 113 ** <a href="http://www.fossil-scm.org/">Fossil configuration management 114 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115 ** a string which identifies a particular check-in of SQLite 116 ** within its configuration management system. ^The SQLITE_SOURCE_ID 117 ** string contains the date and time of the check-in (UTC) and a SHA1 118 ** or SHA3-256 hash of the entire source tree. If the source code has 119 ** been edited in any way since it was last checked in, then the last 120 ** four hexadecimal digits of the hash may be modified. 121 ** 122 ** See also: [sqlite3_libversion()], 123 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124 ** [sqlite_version()] and [sqlite_source_id()]. 125 */ 126 #define SQLITE_VERSION "3.26.0" 127 #define SQLITE_VERSION_NUMBER 3026000 128 #define SQLITE_SOURCE_ID "2018-12-01 12:34:55 bf8c1b2b7a5960c282e543b9c293686dccff272512d08865f4600fb58238b4f9" 129 130 /* 131 ** CAPI3REF: Run-Time Library Version Numbers 132 ** KEYWORDS: sqlite3_version sqlite3_sourceid 133 ** 134 ** These interfaces provide the same information as the [SQLITE_VERSION], 135 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136 ** but are associated with the library instead of the header file. ^(Cautious 137 ** programmers might include assert() statements in their application to 138 ** verify that values returned by these interfaces match the macros in 139 ** the header, and thus ensure that the application is 140 ** compiled with matching library and header files. 141 ** 142 ** <blockquote><pre> 143 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146 ** </pre></blockquote>)^ 147 ** 148 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149 ** macro. ^The sqlite3_libversion() function returns a pointer to the 150 ** to the sqlite3_version[] string constant. The sqlite3_libversion() 151 ** function is provided for use in DLLs since DLL users usually do not have 152 ** direct access to string constants within the DLL. ^The 153 ** sqlite3_libversion_number() function returns an integer equal to 154 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155 ** a pointer to a string constant whose value is the same as the 156 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157 ** using an edited copy of [the amalgamation], then the last four characters 158 ** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159 ** 160 ** See also: [sqlite_version()] and [sqlite_source_id()]. 161 */ 162 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 163 SQLITE_API const char *sqlite3_libversion(void); 164 SQLITE_API const char *sqlite3_sourceid(void); 165 SQLITE_API int sqlite3_libversion_number(void); 166 167 /* 168 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169 ** 170 ** ^The sqlite3_compileoption_used() function returns 0 or 1 171 ** indicating whether the specified option was defined at 172 ** compile time. ^The SQLITE_ prefix may be omitted from the 173 ** option name passed to sqlite3_compileoption_used(). 174 ** 175 ** ^The sqlite3_compileoption_get() function allows iterating 176 ** over the list of options that were defined at compile time by 177 ** returning the N-th compile time option string. ^If N is out of range, 178 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179 ** prefix is omitted from any strings returned by 180 ** sqlite3_compileoption_get(). 181 ** 182 ** ^Support for the diagnostic functions sqlite3_compileoption_used() 183 ** and sqlite3_compileoption_get() may be omitted by specifying the 184 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185 ** 186 ** See also: SQL functions [sqlite_compileoption_used()] and 187 ** [sqlite_compileoption_get()] and the [compile_options pragma]. 188 */ 189 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 191 SQLITE_API const char *sqlite3_compileoption_get(int N); 192 #endif 193 194 /* 195 ** CAPI3REF: Test To See If The Library Is Threadsafe 196 ** 197 ** ^The sqlite3_threadsafe() function returns zero if and only if 198 ** SQLite was compiled with mutexing code omitted due to the 199 ** [SQLITE_THREADSAFE] compile-time option being set to 0. 200 ** 201 ** SQLite can be compiled with or without mutexes. When 202 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203 ** are enabled and SQLite is threadsafe. When the 204 ** [SQLITE_THREADSAFE] macro is 0, 205 ** the mutexes are omitted. Without the mutexes, it is not safe 206 ** to use SQLite concurrently from more than one thread. 207 ** 208 ** Enabling mutexes incurs a measurable performance penalty. 209 ** So if speed is of utmost importance, it makes sense to disable 210 ** the mutexes. But for maximum safety, mutexes should be enabled. 211 ** ^The default behavior is for mutexes to be enabled. 212 ** 213 ** This interface can be used by an application to make sure that the 214 ** version of SQLite that it is linking against was compiled with 215 ** the desired setting of the [SQLITE_THREADSAFE] macro. 216 ** 217 ** This interface only reports on the compile-time mutex setting 218 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220 ** can be fully or partially disabled using a call to [sqlite3_config()] 221 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223 ** sqlite3_threadsafe() function shows only the compile-time setting of 224 ** thread safety, not any run-time changes to that setting made by 225 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226 ** is unchanged by calls to sqlite3_config().)^ 227 ** 228 ** See the [threading mode] documentation for additional information. 229 */ 230 SQLITE_API int sqlite3_threadsafe(void); 231 232 /* 233 ** CAPI3REF: Database Connection Handle 234 ** KEYWORDS: {database connection} {database connections} 235 ** 236 ** Each open SQLite database is represented by a pointer to an instance of 237 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240 ** and [sqlite3_close_v2()] are its destructors. There are many other 241 ** interfaces (such as 242 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243 ** [sqlite3_busy_timeout()] to name but three) that are methods on an 244 ** sqlite3 object. 245 */ 246 typedef struct sqlite3 sqlite3; 247 248 /* 249 ** CAPI3REF: 64-Bit Integer Types 250 ** KEYWORDS: sqlite_int64 sqlite_uint64 251 ** 252 ** Because there is no cross-platform way to specify 64-bit integer types 253 ** SQLite includes typedefs for 64-bit signed and unsigned integers. 254 ** 255 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257 ** compatibility only. 258 ** 259 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261 ** sqlite3_uint64 and sqlite_uint64 types can store integer values 262 ** between 0 and +18446744073709551615 inclusive. 263 */ 264 #ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266 # ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268 # else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270 # endif 271 #elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274 #else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277 #endif 278 typedef sqlite_int64 sqlite3_int64; 279 typedef sqlite_uint64 sqlite3_uint64; 280 281 /* 282 ** If compiling for a processor that lacks floating point support, 283 ** substitute integer for floating-point. 284 */ 285 #ifdef SQLITE_OMIT_FLOATING_POINT 286 # define double sqlite3_int64 287 #endif 288 289 /* 290 ** CAPI3REF: Closing A Database Connection 291 ** DESTRUCTOR: sqlite3 292 ** 293 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294 ** for the [sqlite3] object. 295 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296 ** the [sqlite3] object is successfully destroyed and all associated 297 ** resources are deallocated. 298 ** 299 ** ^If the database connection is associated with unfinalized prepared 300 ** statements or unfinished sqlite3_backup objects then sqlite3_close() 301 ** will leave the database connection open and return [SQLITE_BUSY]. 302 ** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303 ** and/or unfinished sqlite3_backups, then the database connection becomes 304 ** an unusable "zombie" which will automatically be deallocated when the 305 ** last prepared statement is finalized or the last sqlite3_backup is 306 ** finished. The sqlite3_close_v2() interface is intended for use with 307 ** host languages that are garbage collected, and where the order in which 308 ** destructors are called is arbitrary. 309 ** 310 ** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311 ** [sqlite3_blob_close | close] all [BLOB handles], and 312 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313 ** with the [sqlite3] object prior to attempting to close the object. ^If 314 ** sqlite3_close_v2() is called on a [database connection] that still has 315 ** outstanding [prepared statements], [BLOB handles], and/or 316 ** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317 ** of resources is deferred until all [prepared statements], [BLOB handles], 318 ** and [sqlite3_backup] objects are also destroyed. 319 ** 320 ** ^If an [sqlite3] object is destroyed while a transaction is open, 321 ** the transaction is automatically rolled back. 322 ** 323 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324 ** must be either a NULL 325 ** pointer or an [sqlite3] object pointer obtained 326 ** from [sqlite3_open()], [sqlite3_open16()], or 327 ** [sqlite3_open_v2()], and not previously closed. 328 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329 ** argument is a harmless no-op. 330 */ 331 SQLITE_API int sqlite3_close(sqlite3*); 332 SQLITE_API int sqlite3_close_v2(sqlite3*); 333 334 /* 335 ** The type for a callback function. 336 ** This is legacy and deprecated. It is included for historical 337 ** compatibility and is not documented. 338 */ 339 typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341 /* 342 ** CAPI3REF: One-Step Query Execution Interface 343 ** METHOD: sqlite3 344 ** 345 ** The sqlite3_exec() interface is a convenience wrapper around 346 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347 ** that allows an application to run multiple statements of SQL 348 ** without having to use a lot of C code. 349 ** 350 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351 ** semicolon-separate SQL statements passed into its 2nd argument, 352 ** in the context of the [database connection] passed in as its 1st 353 ** argument. ^If the callback function of the 3rd argument to 354 ** sqlite3_exec() is not NULL, then it is invoked for each result row 355 ** coming out of the evaluated SQL statements. ^The 4th argument to 356 ** sqlite3_exec() is relayed through to the 1st argument of each 357 ** callback invocation. ^If the callback pointer to sqlite3_exec() 358 ** is NULL, then no callback is ever invoked and result rows are 359 ** ignored. 360 ** 361 ** ^If an error occurs while evaluating the SQL statements passed into 362 ** sqlite3_exec(), then execution of the current statement stops and 363 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364 ** is not NULL then any error message is written into memory obtained 365 ** from [sqlite3_malloc()] and passed back through the 5th parameter. 366 ** To avoid memory leaks, the application should invoke [sqlite3_free()] 367 ** on error message strings returned through the 5th parameter of 368 ** sqlite3_exec() after the error message string is no longer needed. 369 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371 ** NULL before returning. 372 ** 373 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374 ** routine returns SQLITE_ABORT without invoking the callback again and 375 ** without running any subsequent SQL statements. 376 ** 377 ** ^The 2nd argument to the sqlite3_exec() callback function is the 378 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379 ** callback is an array of pointers to strings obtained as if from 380 ** [sqlite3_column_text()], one for each column. ^If an element of a 381 ** result row is NULL then the corresponding string pointer for the 382 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383 ** sqlite3_exec() callback is an array of pointers to strings where each 384 ** entry represents the name of corresponding result column as obtained 385 ** from [sqlite3_column_name()]. 386 ** 387 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388 ** to an empty string, or a pointer that contains only whitespace and/or 389 ** SQL comments, then no SQL statements are evaluated and the database 390 ** is not changed. 391 ** 392 ** Restrictions: 393 ** 394 ** <ul> 395 ** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396 ** is a valid and open [database connection]. 397 ** <li> The application must not close the [database connection] specified by 398 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399 ** <li> The application must not modify the SQL statement text passed into 400 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401 ** </ul> 402 */ 403 SQLITE_API int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409 ); 410 411 /* 412 ** CAPI3REF: Result Codes 413 ** KEYWORDS: {result code definitions} 414 ** 415 ** Many SQLite functions return an integer result code from the set shown 416 ** here in order to indicate success or failure. 417 ** 418 ** New error codes may be added in future versions of SQLite. 419 ** 420 ** See also: [extended result code definitions] 421 */ 422 #define SQLITE_OK 0 /* Successful result */ 423 /* beginning-of-error-codes */ 424 #define SQLITE_ERROR 1 /* Generic error */ 425 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426 #define SQLITE_PERM 3 /* Access permission denied */ 427 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428 #define SQLITE_BUSY 5 /* The database file is locked */ 429 #define SQLITE_LOCKED 6 /* A table in the database is locked */ 430 #define SQLITE_NOMEM 7 /* A malloc() failed */ 431 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436 #define SQLITE_FULL 13 /* Insertion failed because database is full */ 437 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439 #define SQLITE_EMPTY 16 /* Internal use only */ 440 #define SQLITE_SCHEMA 17 /* The database schema changed */ 441 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443 #define SQLITE_MISMATCH 20 /* Data type mismatch */ 444 #define SQLITE_MISUSE 21 /* Library used incorrectly */ 445 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446 #define SQLITE_AUTH 23 /* Authorization denied */ 447 #define SQLITE_FORMAT 24 /* Not used */ 448 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454 /* end-of-error-codes */ 455 456 /* 457 ** CAPI3REF: Extended Result Codes 458 ** KEYWORDS: {extended result code definitions} 459 ** 460 ** In its default configuration, SQLite API routines return one of 30 integer 461 ** [result codes]. However, experience has shown that many of 462 ** these result codes are too coarse-grained. They do not provide as 463 ** much information about problems as programmers might like. In an effort to 464 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465 ** and later) include 466 ** support for additional result codes that provide more detailed information 467 ** about errors. These [extended result codes] are enabled or disabled 468 ** on a per database connection basis using the 469 ** [sqlite3_extended_result_codes()] API. Or, the extended code for 470 ** the most recent error can be obtained using 471 ** [sqlite3_extended_errcode()]. 472 */ 473 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 476 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 477 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 478 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 479 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 480 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 481 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 482 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 483 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 484 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 485 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 486 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 487 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 488 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 489 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 490 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 491 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 492 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 493 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 494 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 495 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 496 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 497 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 498 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 499 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 500 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 501 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 502 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 503 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 504 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 505 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 506 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 507 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 508 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 509 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 510 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 511 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 512 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 513 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 514 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 515 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 516 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 517 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 518 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 519 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 520 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 521 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 522 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 523 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 524 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 525 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 526 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 527 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 528 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 529 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 530 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 531 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 532 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 533 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 534 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 535 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 536 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 537 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 538 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 539 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 540 541 /* 542 ** CAPI3REF: Flags For File Open Operations 543 ** 544 ** These bit values are intended for use in the 545 ** 3rd parameter to the [sqlite3_open_v2()] interface and 546 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 547 */ 548 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 549 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 550 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 551 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 552 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 553 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 554 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 555 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 556 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 557 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 558 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 559 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 560 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 561 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 562 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 563 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 564 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 565 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 566 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 567 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 568 569 /* Reserved: 0x00F00000 */ 570 571 /* 572 ** CAPI3REF: Device Characteristics 573 ** 574 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] 575 ** object returns an integer which is a vector of these 576 ** bit values expressing I/O characteristics of the mass storage 577 ** device that holds the file that the [sqlite3_io_methods] 578 ** refers to. 579 ** 580 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 581 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 582 ** mean that writes of blocks that are nnn bytes in size and 583 ** are aligned to an address which is an integer multiple of 584 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 585 ** that when data is appended to a file, the data is appended 586 ** first then the size of the file is extended, never the other 587 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 588 ** information is written to disk in the same order as calls 589 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 590 ** after reboot following a crash or power loss, the only bytes in a 591 ** file that were written at the application level might have changed 592 ** and that adjacent bytes, even bytes within the same sector are 593 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 594 ** flag indicates that a file cannot be deleted when open. The 595 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 596 ** read-only media and cannot be changed even by processes with 597 ** elevated privileges. 598 ** 599 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 600 ** filesystem supports doing multiple write operations atomically when those 601 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 602 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 603 */ 604 #define SQLITE_IOCAP_ATOMIC 0x00000001 605 #define SQLITE_IOCAP_ATOMIC512 0x00000002 606 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 607 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 608 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 609 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 610 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 611 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 612 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 613 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 614 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 615 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 616 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 617 #define SQLITE_IOCAP_IMMUTABLE 0x00002000 618 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 619 620 /* 621 ** CAPI3REF: File Locking Levels 622 ** 623 ** SQLite uses one of these integer values as the second 624 ** argument to calls it makes to the xLock() and xUnlock() methods 625 ** of an [sqlite3_io_methods] object. 626 */ 627 #define SQLITE_LOCK_NONE 0 628 #define SQLITE_LOCK_SHARED 1 629 #define SQLITE_LOCK_RESERVED 2 630 #define SQLITE_LOCK_PENDING 3 631 #define SQLITE_LOCK_EXCLUSIVE 4 632 633 /* 634 ** CAPI3REF: Synchronization Type Flags 635 ** 636 ** When SQLite invokes the xSync() method of an 637 ** [sqlite3_io_methods] object it uses a combination of 638 ** these integer values as the second argument. 639 ** 640 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 641 ** sync operation only needs to flush data to mass storage. Inode 642 ** information need not be flushed. If the lower four bits of the flag 643 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 644 ** If the lower four bits equal SQLITE_SYNC_FULL, that means 645 ** to use Mac OS X style fullsync instead of fsync(). 646 ** 647 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 648 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 649 ** settings. The [synchronous pragma] determines when calls to the 650 ** xSync VFS method occur and applies uniformly across all platforms. 651 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 652 ** energetic or rigorous or forceful the sync operations are and 653 ** only make a difference on Mac OSX for the default SQLite code. 654 ** (Third-party VFS implementations might also make the distinction 655 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 656 ** operating systems natively supported by SQLite, only Mac OSX 657 ** cares about the difference.) 658 */ 659 #define SQLITE_SYNC_NORMAL 0x00002 660 #define SQLITE_SYNC_FULL 0x00003 661 #define SQLITE_SYNC_DATAONLY 0x00010 662 663 /* 664 ** CAPI3REF: OS Interface Open File Handle 665 ** 666 ** An [sqlite3_file] object represents an open file in the 667 ** [sqlite3_vfs | OS interface layer]. Individual OS interface 668 ** implementations will 669 ** want to subclass this object by appending additional fields 670 ** for their own use. The pMethods entry is a pointer to an 671 ** [sqlite3_io_methods] object that defines methods for performing 672 ** I/O operations on the open file. 673 */ 674 typedef struct sqlite3_file sqlite3_file; 675 struct sqlite3_file { 676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 677 }; 678 679 /* 680 ** CAPI3REF: OS Interface File Virtual Methods Object 681 ** 682 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an 683 ** [sqlite3_file] object (or, more commonly, a subclass of the 684 ** [sqlite3_file] object) with a pointer to an instance of this object. 685 ** This object defines the methods used to perform various operations 686 ** against the open file represented by the [sqlite3_file] object. 687 ** 688 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 689 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 690 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 691 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 692 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 693 ** to NULL. 694 ** 695 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 696 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 697 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 698 ** flag may be ORed in to indicate that only the data of the file 699 ** and not its inode needs to be synced. 700 ** 701 ** The integer values to xLock() and xUnlock() are one of 702 ** <ul> 703 ** <li> [SQLITE_LOCK_NONE], 704 ** <li> [SQLITE_LOCK_SHARED], 705 ** <li> [SQLITE_LOCK_RESERVED], 706 ** <li> [SQLITE_LOCK_PENDING], or 707 ** <li> [SQLITE_LOCK_EXCLUSIVE]. 708 ** </ul> 709 ** xLock() increases the lock. xUnlock() decreases the lock. 710 ** The xCheckReservedLock() method checks whether any database connection, 711 ** either in this process or in some other process, is holding a RESERVED, 712 ** PENDING, or EXCLUSIVE lock on the file. It returns true 713 ** if such a lock exists and false otherwise. 714 ** 715 ** The xFileControl() method is a generic interface that allows custom 716 ** VFS implementations to directly control an open file using the 717 ** [sqlite3_file_control()] interface. The second "op" argument is an 718 ** integer opcode. The third argument is a generic pointer intended to 719 ** point to a structure that may contain arguments or space in which to 720 ** write return values. Potential uses for xFileControl() might be 721 ** functions to enable blocking locks with timeouts, to change the 722 ** locking strategy (for example to use dot-file locks), to inquire 723 ** about the status of a lock, or to break stale locks. The SQLite 724 ** core reserves all opcodes less than 100 for its own use. 725 ** A [file control opcodes | list of opcodes] less than 100 is available. 726 ** Applications that define a custom xFileControl method should use opcodes 727 ** greater than 100 to avoid conflicts. VFS implementations should 728 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not 729 ** recognize. 730 ** 731 ** The xSectorSize() method returns the sector size of the 732 ** device that underlies the file. The sector size is the 733 ** minimum write that can be performed without disturbing 734 ** other bytes in the file. The xDeviceCharacteristics() 735 ** method returns a bit vector describing behaviors of the 736 ** underlying device: 737 ** 738 ** <ul> 739 ** <li> [SQLITE_IOCAP_ATOMIC] 740 ** <li> [SQLITE_IOCAP_ATOMIC512] 741 ** <li> [SQLITE_IOCAP_ATOMIC1K] 742 ** <li> [SQLITE_IOCAP_ATOMIC2K] 743 ** <li> [SQLITE_IOCAP_ATOMIC4K] 744 ** <li> [SQLITE_IOCAP_ATOMIC8K] 745 ** <li> [SQLITE_IOCAP_ATOMIC16K] 746 ** <li> [SQLITE_IOCAP_ATOMIC32K] 747 ** <li> [SQLITE_IOCAP_ATOMIC64K] 748 ** <li> [SQLITE_IOCAP_SAFE_APPEND] 749 ** <li> [SQLITE_IOCAP_SEQUENTIAL] 750 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 751 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 752 ** <li> [SQLITE_IOCAP_IMMUTABLE] 753 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 754 ** </ul> 755 ** 756 ** The SQLITE_IOCAP_ATOMIC property means that all writes of 757 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 758 ** mean that writes of blocks that are nnn bytes in size and 759 ** are aligned to an address which is an integer multiple of 760 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 761 ** that when data is appended to a file, the data is appended 762 ** first then the size of the file is extended, never the other 763 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 764 ** information is written to disk in the same order as calls 765 ** to xWrite(). 766 ** 767 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 768 ** in the unread portions of the buffer with zeros. A VFS that 769 ** fails to zero-fill short reads might seem to work. However, 770 ** failure to zero-fill short reads will eventually lead to 771 ** database corruption. 772 */ 773 typedef struct sqlite3_io_methods sqlite3_io_methods; 774 struct sqlite3_io_methods { 775 int iVersion; 776 int (*xClose)(sqlite3_file*); 777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 780 int (*xSync)(sqlite3_file*, int flags); 781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 782 int (*xLock)(sqlite3_file*, int); 783 int (*xUnlock)(sqlite3_file*, int); 784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 785 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 786 int (*xSectorSize)(sqlite3_file*); 787 int (*xDeviceCharacteristics)(sqlite3_file*); 788 /* Methods above are valid for version 1 */ 789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 791 void (*xShmBarrier)(sqlite3_file*); 792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 793 /* Methods above are valid for version 2 */ 794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 796 /* Methods above are valid for version 3 */ 797 /* Additional methods may be added in future releases */ 798 }; 799 800 /* 801 ** CAPI3REF: Standard File Control Opcodes 802 ** KEYWORDS: {file control opcodes} {file control opcode} 803 ** 804 ** These integer constants are opcodes for the xFileControl method 805 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 806 ** interface. 807 ** 808 ** <ul> 809 ** <li>[[SQLITE_FCNTL_LOCKSTATE]] 810 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 811 ** opcode causes the xFileControl method to write the current state of 812 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 813 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 814 ** into an integer that the pArg argument points to. This capability 815 ** is used during testing and is only available when the SQLITE_TEST 816 ** compile-time option is used. 817 ** 818 ** <li>[[SQLITE_FCNTL_SIZE_HINT]] 819 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 820 ** layer a hint of how large the database file will grow to be during the 821 ** current transaction. This hint is not guaranteed to be accurate but it 822 ** is often close. The underlying VFS might choose to preallocate database 823 ** file space based on this hint in order to help writes to the database 824 ** file run faster. 825 ** 826 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 827 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 828 ** extends and truncates the database file in chunks of a size specified 829 ** by the user. The fourth argument to [sqlite3_file_control()] should 830 ** point to an integer (type int) containing the new chunk-size to use 831 ** for the nominated database. Allocating database file space in large 832 ** chunks (say 1MB at a time), may reduce file-system fragmentation and 833 ** improve performance on some systems. 834 ** 835 ** <li>[[SQLITE_FCNTL_FILE_POINTER]] 836 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 837 ** to the [sqlite3_file] object associated with a particular database 838 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 839 ** 840 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 841 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 842 ** to the [sqlite3_file] object associated with the journal file (either 843 ** the [rollback journal] or the [write-ahead log]) for a particular database 844 ** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 845 ** 846 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 847 ** No longer in use. 848 ** 849 ** <li>[[SQLITE_FCNTL_SYNC]] 850 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 851 ** sent to the VFS immediately before the xSync method is invoked on a 852 ** database file descriptor. Or, if the xSync method is not invoked 853 ** because the user has configured SQLite with 854 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 855 ** of the xSync method. In most cases, the pointer argument passed with 856 ** this file-control is NULL. However, if the database file is being synced 857 ** as part of a multi-database commit, the argument points to a nul-terminated 858 ** string containing the transactions master-journal file name. VFSes that 859 ** do not need this signal should silently ignore this opcode. Applications 860 ** should not call [sqlite3_file_control()] with this opcode as doing so may 861 ** disrupt the operation of the specialized VFSes that do require it. 862 ** 863 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 864 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 865 ** and sent to the VFS after a transaction has been committed immediately 866 ** but before the database is unlocked. VFSes that do not need this signal 867 ** should silently ignore this opcode. Applications should not call 868 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the 869 ** operation of the specialized VFSes that do require it. 870 ** 871 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 872 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 873 ** retry counts and intervals for certain disk I/O operations for the 874 ** windows [VFS] in order to provide robustness in the presence of 875 ** anti-virus programs. By default, the windows VFS will retry file read, 876 ** file write, and file delete operations up to 10 times, with a delay 877 ** of 25 milliseconds before the first retry and with the delay increasing 878 ** by an additional 25 milliseconds with each subsequent retry. This 879 ** opcode allows these two values (10 retries and 25 milliseconds of delay) 880 ** to be adjusted. The values are changed for all database connections 881 ** within the same process. The argument is a pointer to an array of two 882 ** integers where the first integer is the new retry count and the second 883 ** integer is the delay. If either integer is negative, then the setting 884 ** is not changed but instead the prior value of that setting is written 885 ** into the array entry, allowing the current retry settings to be 886 ** interrogated. The zDbName parameter is ignored. 887 ** 888 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 889 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 890 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 891 ** write ahead log ([WAL file]) and shared memory 892 ** files used for transaction control 893 ** are automatically deleted when the latest connection to the database 894 ** closes. Setting persistent WAL mode causes those files to persist after 895 ** close. Persisting the files is useful when other processes that do not 896 ** have write permission on the directory containing the database file want 897 ** to read the database file, as the WAL and shared memory files must exist 898 ** in order for the database to be readable. The fourth parameter to 899 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 900 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 901 ** WAL mode. If the integer is -1, then it is overwritten with the current 902 ** WAL persistence setting. 903 ** 904 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 905 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 906 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 907 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 908 ** xDeviceCharacteristics methods. The fourth parameter to 909 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 910 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 911 ** mode. If the integer is -1, then it is overwritten with the current 912 ** zero-damage mode setting. 913 ** 914 ** <li>[[SQLITE_FCNTL_OVERWRITE]] 915 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 916 ** a write transaction to indicate that, unless it is rolled back for some 917 ** reason, the entire database file will be overwritten by the current 918 ** transaction. This is used by VACUUM operations. 919 ** 920 ** <li>[[SQLITE_FCNTL_VFSNAME]] 921 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 922 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the 923 ** final bottom-level VFS are written into memory obtained from 924 ** [sqlite3_malloc()] and the result is stored in the char* variable 925 ** that the fourth parameter of [sqlite3_file_control()] points to. 926 ** The caller is responsible for freeing the memory when done. As with 927 ** all file-control actions, there is no guarantee that this will actually 928 ** do anything. Callers should initialize the char* variable to a NULL 929 ** pointer in case this file-control is not implemented. This file-control 930 ** is intended for diagnostic use only. 931 ** 932 ** <li>[[SQLITE_FCNTL_VFS_POINTER]] 933 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 934 ** [VFSes] currently in use. ^(The argument X in 935 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 936 ** of type "[sqlite3_vfs] **". This opcodes will set *X 937 ** to a pointer to the top-level VFS.)^ 938 ** ^When there are multiple VFS shims in the stack, this opcode finds the 939 ** upper-most shim only. 940 ** 941 ** <li>[[SQLITE_FCNTL_PRAGMA]] 942 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 943 ** file control is sent to the open [sqlite3_file] object corresponding 944 ** to the database file to which the pragma statement refers. ^The argument 945 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 946 ** pointers to strings (char**) in which the second element of the array 947 ** is the name of the pragma and the third element is the argument to the 948 ** pragma or NULL if the pragma has no argument. ^The handler for an 949 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 950 ** of the char** argument point to a string obtained from [sqlite3_mprintf()] 951 ** or the equivalent and that string will become the result of the pragma or 952 ** the error message if the pragma fails. ^If the 953 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 954 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 955 ** file control returns [SQLITE_OK], then the parser assumes that the 956 ** VFS has handled the PRAGMA itself and the parser generates a no-op 957 ** prepared statement if result string is NULL, or that returns a copy 958 ** of the result string if the string is non-NULL. 959 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 960 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 961 ** that the VFS encountered an error while handling the [PRAGMA] and the 962 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 963 ** file control occurs at the beginning of pragma statement analysis and so 964 ** it is able to override built-in [PRAGMA] statements. 965 ** 966 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 967 ** ^The [SQLITE_FCNTL_BUSYHANDLER] 968 ** file-control may be invoked by SQLite on the database file handle 969 ** shortly after it is opened in order to provide a custom VFS with access 970 ** to the connections busy-handler callback. The argument is of type (void **) 971 ** - an array of two (void *) values. The first (void *) actually points 972 ** to a function of type (int (*)(void *)). In order to invoke the connections 973 ** busy-handler, this function should be invoked with the second (void *) in 974 ** the array as the only argument. If it returns non-zero, then the operation 975 ** should be retried. If it returns zero, the custom VFS should abandon the 976 ** current operation. 977 ** 978 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 979 ** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 980 ** to have SQLite generate a 981 ** temporary filename using the same algorithm that is followed to generate 982 ** temporary filenames for TEMP tables and other internal uses. The 983 ** argument should be a char** which will be filled with the filename 984 ** written into memory obtained from [sqlite3_malloc()]. The caller should 985 ** invoke [sqlite3_free()] on the result to avoid a memory leak. 986 ** 987 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 988 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 989 ** maximum number of bytes that will be used for memory-mapped I/O. 990 ** The argument is a pointer to a value of type sqlite3_int64 that 991 ** is an advisory maximum number of bytes in the file to memory map. The 992 ** pointer is overwritten with the old value. The limit is not changed if 993 ** the value originally pointed to is negative, and so the current limit 994 ** can be queried by passing in a pointer to a negative number. This 995 ** file-control is used internally to implement [PRAGMA mmap_size]. 996 ** 997 ** <li>[[SQLITE_FCNTL_TRACE]] 998 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information 999 ** to the VFS about what the higher layers of the SQLite stack are doing. 1000 ** This file control is used by some VFS activity tracing [shims]. 1001 ** The argument is a zero-terminated string. Higher layers in the 1002 ** SQLite stack may generate instances of this file control if 1003 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1004 ** 1005 ** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1006 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1007 ** pointer to an integer and it writes a boolean into that integer depending 1008 ** on whether or not the file has been renamed, moved, or deleted since it 1009 ** was first opened. 1010 ** 1011 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1012 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1013 ** underlying native file handle associated with a file handle. This file 1014 ** control interprets its argument as a pointer to a native file handle and 1015 ** writes the resulting value there. 1016 ** 1017 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1018 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1019 ** opcode causes the xFileControl method to swap the file handle with the one 1020 ** pointed to by the pArg argument. This capability is used during testing 1021 ** and only needs to be supported when SQLITE_TEST is defined. 1022 ** 1023 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1024 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1025 ** be advantageous to block on the next WAL lock if the lock is not immediately 1026 ** available. The WAL subsystem issues this signal during rare 1027 ** circumstances in order to fix a problem with priority inversion. 1028 ** Applications should <em>not</em> use this file-control. 1029 ** 1030 ** <li>[[SQLITE_FCNTL_ZIPVFS]] 1031 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1032 ** VFS should return SQLITE_NOTFOUND for this opcode. 1033 ** 1034 ** <li>[[SQLITE_FCNTL_RBU]] 1035 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1036 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1037 ** this opcode. 1038 ** 1039 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1040 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1041 ** the file descriptor is placed in "batch write mode", which 1042 ** means all subsequent write operations will be deferred and done 1043 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1044 ** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1045 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1046 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1047 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1048 ** no VFS interface calls on the same [sqlite3_file] file descriptor 1049 ** except for calls to the xWrite method and the xFileControl method 1050 ** with [SQLITE_FCNTL_SIZE_HINT]. 1051 ** 1052 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1053 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1054 ** operations since the previous successful call to 1055 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1056 ** This file control returns [SQLITE_OK] if and only if the writes were 1057 ** all performed successfully and have been committed to persistent storage. 1058 ** ^Regardless of whether or not it is successful, this file control takes 1059 ** the file descriptor out of batch write mode so that all subsequent 1060 ** write operations are independent. 1061 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1062 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1063 ** 1064 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1065 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1066 ** operations since the previous successful call to 1067 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1068 ** ^This file control takes the file descriptor out of batch write mode 1069 ** so that all subsequent write operations are independent. 1070 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1071 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1072 ** 1073 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1074 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1075 ** a file lock using the xLock or xShmLock methods of the VFS to wait 1076 ** for up to M milliseconds before failing, where M is the single 1077 ** unsigned integer parameter. 1078 ** 1079 ** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1080 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1081 ** a database file. The argument is a pointer to a 32-bit unsigned integer. 1082 ** The "data version" for the pager is written into the pointer. The 1083 ** "data version" changes whenever any change occurs to the corresponding 1084 ** database file, either through SQL statements on the same database 1085 ** connection or through transactions committed by separate database 1086 ** connections possibly in other processes. The [sqlite3_total_changes()] 1087 ** interface can be used to find if any database on the connection has changed, 1088 ** but that interface responds to changes on TEMP as well as MAIN and does 1089 ** not provide a mechanism to detect changes to MAIN only. Also, the 1090 ** [sqlite3_total_changes()] interface responds to internal changes only and 1091 ** omits changes made by other database connections. The 1092 ** [PRAGMA data_version] command provide a mechanism to detect changes to 1093 ** a single attached database that occur due to other database connections, 1094 ** but omits changes implemented by the database connection on which it is 1095 ** called. This file control is the only mechanism to detect changes that 1096 ** happen either internally or externally and that are associated with 1097 ** a particular attached database. 1098 ** </ul> 1099 */ 1100 #define SQLITE_FCNTL_LOCKSTATE 1 1101 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1102 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1103 #define SQLITE_FCNTL_LAST_ERRNO 4 1104 #define SQLITE_FCNTL_SIZE_HINT 5 1105 #define SQLITE_FCNTL_CHUNK_SIZE 6 1106 #define SQLITE_FCNTL_FILE_POINTER 7 1107 #define SQLITE_FCNTL_SYNC_OMITTED 8 1108 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 1109 #define SQLITE_FCNTL_PERSIST_WAL 10 1110 #define SQLITE_FCNTL_OVERWRITE 11 1111 #define SQLITE_FCNTL_VFSNAME 12 1112 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1113 #define SQLITE_FCNTL_PRAGMA 14 1114 #define SQLITE_FCNTL_BUSYHANDLER 15 1115 #define SQLITE_FCNTL_TEMPFILENAME 16 1116 #define SQLITE_FCNTL_MMAP_SIZE 18 1117 #define SQLITE_FCNTL_TRACE 19 1118 #define SQLITE_FCNTL_HAS_MOVED 20 1119 #define SQLITE_FCNTL_SYNC 21 1120 #define SQLITE_FCNTL_COMMIT_PHASETWO 22 1121 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1122 #define SQLITE_FCNTL_WAL_BLOCK 24 1123 #define SQLITE_FCNTL_ZIPVFS 25 1124 #define SQLITE_FCNTL_RBU 26 1125 #define SQLITE_FCNTL_VFS_POINTER 27 1126 #define SQLITE_FCNTL_JOURNAL_POINTER 28 1127 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1128 #define SQLITE_FCNTL_PDB 30 1129 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1130 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1131 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1132 #define SQLITE_FCNTL_LOCK_TIMEOUT 34 1133 #define SQLITE_FCNTL_DATA_VERSION 35 1134 1135 /* deprecated names */ 1136 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1137 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1138 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1139 1140 1141 /* 1142 ** CAPI3REF: Mutex Handle 1143 ** 1144 ** The mutex module within SQLite defines [sqlite3_mutex] to be an 1145 ** abstract type for a mutex object. The SQLite core never looks 1146 ** at the internal representation of an [sqlite3_mutex]. It only 1147 ** deals with pointers to the [sqlite3_mutex] object. 1148 ** 1149 ** Mutexes are created using [sqlite3_mutex_alloc()]. 1150 */ 1151 typedef struct sqlite3_mutex sqlite3_mutex; 1152 1153 /* 1154 ** CAPI3REF: Loadable Extension Thunk 1155 ** 1156 ** A pointer to the opaque sqlite3_api_routines structure is passed as 1157 ** the third parameter to entry points of [loadable extensions]. This 1158 ** structure must be typedefed in order to work around compiler warnings 1159 ** on some platforms. 1160 */ 1161 typedef struct sqlite3_api_routines sqlite3_api_routines; 1162 1163 /* 1164 ** CAPI3REF: OS Interface Object 1165 ** 1166 ** An instance of the sqlite3_vfs object defines the interface between 1167 ** the SQLite core and the underlying operating system. The "vfs" 1168 ** in the name of the object stands for "virtual file system". See 1169 ** the [VFS | VFS documentation] for further information. 1170 ** 1171 ** The VFS interface is sometimes extended by adding new methods onto 1172 ** the end. Each time such an extension occurs, the iVersion field 1173 ** is incremented. The iVersion value started out as 1 in 1174 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1175 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1176 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1177 ** may be appended to the sqlite3_vfs object and the iVersion value 1178 ** may increase again in future versions of SQLite. 1179 ** Note that the structure 1180 ** of the sqlite3_vfs object changes in the transition from 1181 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1182 ** and yet the iVersion field was not modified. 1183 ** 1184 ** The szOsFile field is the size of the subclassed [sqlite3_file] 1185 ** structure used by this VFS. mxPathname is the maximum length of 1186 ** a pathname in this VFS. 1187 ** 1188 ** Registered sqlite3_vfs objects are kept on a linked list formed by 1189 ** the pNext pointer. The [sqlite3_vfs_register()] 1190 ** and [sqlite3_vfs_unregister()] interfaces manage this list 1191 ** in a thread-safe way. The [sqlite3_vfs_find()] interface 1192 ** searches the list. Neither the application code nor the VFS 1193 ** implementation should use the pNext pointer. 1194 ** 1195 ** The pNext field is the only field in the sqlite3_vfs 1196 ** structure that SQLite will ever modify. SQLite will only access 1197 ** or modify this field while holding a particular static mutex. 1198 ** The application should never modify anything within the sqlite3_vfs 1199 ** object once the object has been registered. 1200 ** 1201 ** The zName field holds the name of the VFS module. The name must 1202 ** be unique across all VFS modules. 1203 ** 1204 ** [[sqlite3_vfs.xOpen]] 1205 ** ^SQLite guarantees that the zFilename parameter to xOpen 1206 ** is either a NULL pointer or string obtained 1207 ** from xFullPathname() with an optional suffix added. 1208 ** ^If a suffix is added to the zFilename parameter, it will 1209 ** consist of a single "-" character followed by no more than 1210 ** 11 alphanumeric and/or "-" characters. 1211 ** ^SQLite further guarantees that 1212 ** the string will be valid and unchanged until xClose() is 1213 ** called. Because of the previous sentence, 1214 ** the [sqlite3_file] can safely store a pointer to the 1215 ** filename if it needs to remember the filename for some reason. 1216 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1217 ** must invent its own temporary name for the file. ^Whenever the 1218 ** xFilename parameter is NULL it will also be the case that the 1219 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1220 ** 1221 ** The flags argument to xOpen() includes all bits set in 1222 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1223 ** or [sqlite3_open16()] is used, then flags includes at least 1224 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1225 ** If xOpen() opens a file read-only then it sets *pOutFlags to 1226 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1227 ** 1228 ** ^(SQLite will also add one of the following flags to the xOpen() 1229 ** call, depending on the object being opened: 1230 ** 1231 ** <ul> 1232 ** <li> [SQLITE_OPEN_MAIN_DB] 1233 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1234 ** <li> [SQLITE_OPEN_TEMP_DB] 1235 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1236 ** <li> [SQLITE_OPEN_TRANSIENT_DB] 1237 ** <li> [SQLITE_OPEN_SUBJOURNAL] 1238 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1239 ** <li> [SQLITE_OPEN_WAL] 1240 ** </ul>)^ 1241 ** 1242 ** The file I/O implementation can use the object type flags to 1243 ** change the way it deals with files. For example, an application 1244 ** that does not care about crash recovery or rollback might make 1245 ** the open of a journal file a no-op. Writes to this journal would 1246 ** also be no-ops, and any attempt to read the journal would return 1247 ** SQLITE_IOERR. Or the implementation might recognize that a database 1248 ** file will be doing page-aligned sector reads and writes in a random 1249 ** order and set up its I/O subsystem accordingly. 1250 ** 1251 ** SQLite might also add one of the following flags to the xOpen method: 1252 ** 1253 ** <ul> 1254 ** <li> [SQLITE_OPEN_DELETEONCLOSE] 1255 ** <li> [SQLITE_OPEN_EXCLUSIVE] 1256 ** </ul> 1257 ** 1258 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1259 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1260 ** will be set for TEMP databases and their journals, transient 1261 ** databases, and subjournals. 1262 ** 1263 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1264 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1265 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1266 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1267 ** SQLITE_OPEN_CREATE, is used to indicate that file should always 1268 ** be created, and that it is an error if it already exists. 1269 ** It is <i>not</i> used to indicate the file should be opened 1270 ** for exclusive access. 1271 ** 1272 ** ^At least szOsFile bytes of memory are allocated by SQLite 1273 ** to hold the [sqlite3_file] structure passed as the third 1274 ** argument to xOpen. The xOpen method does not have to 1275 ** allocate the structure; it should just fill it in. Note that 1276 ** the xOpen method must set the sqlite3_file.pMethods to either 1277 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1278 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1279 ** element will be valid after xOpen returns regardless of the success 1280 ** or failure of the xOpen call. 1281 ** 1282 ** [[sqlite3_vfs.xAccess]] 1283 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1284 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1285 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1286 ** to test whether a file is at least readable. The file can be a 1287 ** directory. 1288 ** 1289 ** ^SQLite will always allocate at least mxPathname+1 bytes for the 1290 ** output buffer xFullPathname. The exact size of the output buffer 1291 ** is also passed as a parameter to both methods. If the output buffer 1292 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1293 ** handled as a fatal error by SQLite, vfs implementations should endeavor 1294 ** to prevent this by setting mxPathname to a sufficiently large value. 1295 ** 1296 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1297 ** interfaces are not strictly a part of the filesystem, but they are 1298 ** included in the VFS structure for completeness. 1299 ** The xRandomness() function attempts to return nBytes bytes 1300 ** of good-quality randomness into zOut. The return value is 1301 ** the actual number of bytes of randomness obtained. 1302 ** The xSleep() method causes the calling thread to sleep for at 1303 ** least the number of microseconds given. ^The xCurrentTime() 1304 ** method returns a Julian Day Number for the current date and time as 1305 ** a floating point value. 1306 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1307 ** Day Number multiplied by 86400000 (the number of milliseconds in 1308 ** a 24-hour day). 1309 ** ^SQLite will use the xCurrentTimeInt64() method to get the current 1310 ** date and time if that method is available (if iVersion is 2 or 1311 ** greater and the function pointer is not NULL) and will fall back 1312 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1313 ** 1314 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1315 ** are not used by the SQLite core. These optional interfaces are provided 1316 ** by some VFSes to facilitate testing of the VFS code. By overriding 1317 ** system calls with functions under its control, a test program can 1318 ** simulate faults and error conditions that would otherwise be difficult 1319 ** or impossible to induce. The set of system calls that can be overridden 1320 ** varies from one VFS to another, and from one version of the same VFS to the 1321 ** next. Applications that use these interfaces must be prepared for any 1322 ** or all of these interfaces to be NULL or for their behavior to change 1323 ** from one release to the next. Applications must not attempt to access 1324 ** any of these methods if the iVersion of the VFS is less than 3. 1325 */ 1326 typedef struct sqlite3_vfs sqlite3_vfs; 1327 typedef void (*sqlite3_syscall_ptr)(void); 1328 struct sqlite3_vfs { 1329 int iVersion; /* Structure version number (currently 3) */ 1330 int szOsFile; /* Size of subclassed sqlite3_file */ 1331 int mxPathname; /* Maximum file pathname length */ 1332 sqlite3_vfs *pNext; /* Next registered VFS */ 1333 const char *zName; /* Name of this virtual file system */ 1334 void *pAppData; /* Pointer to application-specific data */ 1335 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1336 int flags, int *pOutFlags); 1337 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1338 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1339 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1340 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1341 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1342 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1343 void (*xDlClose)(sqlite3_vfs*, void*); 1344 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1345 int (*xSleep)(sqlite3_vfs*, int microseconds); 1346 int (*xCurrentTime)(sqlite3_vfs*, double*); 1347 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1348 /* 1349 ** The methods above are in version 1 of the sqlite_vfs object 1350 ** definition. Those that follow are added in version 2 or later 1351 */ 1352 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1353 /* 1354 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1355 ** Those below are for version 3 and greater. 1356 */ 1357 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1358 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1359 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1360 /* 1361 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1362 ** New fields may be appended in future versions. The iVersion 1363 ** value will increment whenever this happens. 1364 */ 1365 }; 1366 1367 /* 1368 ** CAPI3REF: Flags for the xAccess VFS method 1369 ** 1370 ** These integer constants can be used as the third parameter to 1371 ** the xAccess method of an [sqlite3_vfs] object. They determine 1372 ** what kind of permissions the xAccess method is looking for. 1373 ** With SQLITE_ACCESS_EXISTS, the xAccess method 1374 ** simply checks whether the file exists. 1375 ** With SQLITE_ACCESS_READWRITE, the xAccess method 1376 ** checks whether the named directory is both readable and writable 1377 ** (in other words, if files can be added, removed, and renamed within 1378 ** the directory). 1379 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1380 ** [temp_store_directory pragma], though this could change in a future 1381 ** release of SQLite. 1382 ** With SQLITE_ACCESS_READ, the xAccess method 1383 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1384 ** currently unused, though it might be used in a future release of 1385 ** SQLite. 1386 */ 1387 #define SQLITE_ACCESS_EXISTS 0 1388 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1389 #define SQLITE_ACCESS_READ 2 /* Unused */ 1390 1391 /* 1392 ** CAPI3REF: Flags for the xShmLock VFS method 1393 ** 1394 ** These integer constants define the various locking operations 1395 ** allowed by the xShmLock method of [sqlite3_io_methods]. The 1396 ** following are the only legal combinations of flags to the 1397 ** xShmLock method: 1398 ** 1399 ** <ul> 1400 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1401 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1402 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1403 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1404 ** </ul> 1405 ** 1406 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1407 ** was given on the corresponding lock. 1408 ** 1409 ** The xShmLock method can transition between unlocked and SHARED or 1410 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1411 ** and EXCLUSIVE. 1412 */ 1413 #define SQLITE_SHM_UNLOCK 1 1414 #define SQLITE_SHM_LOCK 2 1415 #define SQLITE_SHM_SHARED 4 1416 #define SQLITE_SHM_EXCLUSIVE 8 1417 1418 /* 1419 ** CAPI3REF: Maximum xShmLock index 1420 ** 1421 ** The xShmLock method on [sqlite3_io_methods] may use values 1422 ** between 0 and this upper bound as its "offset" argument. 1423 ** The SQLite core will never attempt to acquire or release a 1424 ** lock outside of this range 1425 */ 1426 #define SQLITE_SHM_NLOCK 8 1427 1428 1429 /* 1430 ** CAPI3REF: Initialize The SQLite Library 1431 ** 1432 ** ^The sqlite3_initialize() routine initializes the 1433 ** SQLite library. ^The sqlite3_shutdown() routine 1434 ** deallocates any resources that were allocated by sqlite3_initialize(). 1435 ** These routines are designed to aid in process initialization and 1436 ** shutdown on embedded systems. Workstation applications using 1437 ** SQLite normally do not need to invoke either of these routines. 1438 ** 1439 ** A call to sqlite3_initialize() is an "effective" call if it is 1440 ** the first time sqlite3_initialize() is invoked during the lifetime of 1441 ** the process, or if it is the first time sqlite3_initialize() is invoked 1442 ** following a call to sqlite3_shutdown(). ^(Only an effective call 1443 ** of sqlite3_initialize() does any initialization. All other calls 1444 ** are harmless no-ops.)^ 1445 ** 1446 ** A call to sqlite3_shutdown() is an "effective" call if it is the first 1447 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1448 ** an effective call to sqlite3_shutdown() does any deinitialization. 1449 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1450 ** 1451 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1452 ** is not. The sqlite3_shutdown() interface must only be called from a 1453 ** single thread. All open [database connections] must be closed and all 1454 ** other SQLite resources must be deallocated prior to invoking 1455 ** sqlite3_shutdown(). 1456 ** 1457 ** Among other things, ^sqlite3_initialize() will invoke 1458 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1459 ** will invoke sqlite3_os_end(). 1460 ** 1461 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1462 ** ^If for some reason, sqlite3_initialize() is unable to initialize 1463 ** the library (perhaps it is unable to allocate a needed resource such 1464 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1465 ** 1466 ** ^The sqlite3_initialize() routine is called internally by many other 1467 ** SQLite interfaces so that an application usually does not need to 1468 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1469 ** calls sqlite3_initialize() so the SQLite library will be automatically 1470 ** initialized when [sqlite3_open()] is called if it has not be initialized 1471 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1472 ** compile-time option, then the automatic calls to sqlite3_initialize() 1473 ** are omitted and the application must call sqlite3_initialize() directly 1474 ** prior to using any other SQLite interface. For maximum portability, 1475 ** it is recommended that applications always invoke sqlite3_initialize() 1476 ** directly prior to using any other SQLite interface. Future releases 1477 ** of SQLite may require this. In other words, the behavior exhibited 1478 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1479 ** default behavior in some future release of SQLite. 1480 ** 1481 ** The sqlite3_os_init() routine does operating-system specific 1482 ** initialization of the SQLite library. The sqlite3_os_end() 1483 ** routine undoes the effect of sqlite3_os_init(). Typical tasks 1484 ** performed by these routines include allocation or deallocation 1485 ** of static resources, initialization of global variables, 1486 ** setting up a default [sqlite3_vfs] module, or setting up 1487 ** a default configuration using [sqlite3_config()]. 1488 ** 1489 ** The application should never invoke either sqlite3_os_init() 1490 ** or sqlite3_os_end() directly. The application should only invoke 1491 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1492 ** interface is called automatically by sqlite3_initialize() and 1493 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1494 ** implementations for sqlite3_os_init() and sqlite3_os_end() 1495 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1496 ** When [custom builds | built for other platforms] 1497 ** (using the [SQLITE_OS_OTHER=1] compile-time 1498 ** option) the application must supply a suitable implementation for 1499 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1500 ** implementation of sqlite3_os_init() or sqlite3_os_end() 1501 ** must return [SQLITE_OK] on success and some other [error code] upon 1502 ** failure. 1503 */ 1504 SQLITE_API int sqlite3_initialize(void); 1505 SQLITE_API int sqlite3_shutdown(void); 1506 SQLITE_API int sqlite3_os_init(void); 1507 SQLITE_API int sqlite3_os_end(void); 1508 1509 /* 1510 ** CAPI3REF: Configuring The SQLite Library 1511 ** 1512 ** The sqlite3_config() interface is used to make global configuration 1513 ** changes to SQLite in order to tune SQLite to the specific needs of 1514 ** the application. The default configuration is recommended for most 1515 ** applications and so this routine is usually not necessary. It is 1516 ** provided to support rare applications with unusual needs. 1517 ** 1518 ** <b>The sqlite3_config() interface is not threadsafe. The application 1519 ** must ensure that no other SQLite interfaces are invoked by other 1520 ** threads while sqlite3_config() is running.</b> 1521 ** 1522 ** The sqlite3_config() interface 1523 ** may only be invoked prior to library initialization using 1524 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1525 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1526 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1527 ** Note, however, that ^sqlite3_config() can be called as part of the 1528 ** implementation of an application-defined [sqlite3_os_init()]. 1529 ** 1530 ** The first argument to sqlite3_config() is an integer 1531 ** [configuration option] that determines 1532 ** what property of SQLite is to be configured. Subsequent arguments 1533 ** vary depending on the [configuration option] 1534 ** in the first argument. 1535 ** 1536 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1537 ** ^If the option is unknown or SQLite is unable to set the option 1538 ** then this routine returns a non-zero [error code]. 1539 */ 1540 SQLITE_API int sqlite3_config(int, ...); 1541 1542 /* 1543 ** CAPI3REF: Configure database connections 1544 ** METHOD: sqlite3 1545 ** 1546 ** The sqlite3_db_config() interface is used to make configuration 1547 ** changes to a [database connection]. The interface is similar to 1548 ** [sqlite3_config()] except that the changes apply to a single 1549 ** [database connection] (specified in the first argument). 1550 ** 1551 ** The second argument to sqlite3_db_config(D,V,...) is the 1552 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1553 ** that indicates what aspect of the [database connection] is being configured. 1554 ** Subsequent arguments vary depending on the configuration verb. 1555 ** 1556 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1557 ** the call is considered successful. 1558 */ 1559 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1560 1561 /* 1562 ** CAPI3REF: Memory Allocation Routines 1563 ** 1564 ** An instance of this object defines the interface between SQLite 1565 ** and low-level memory allocation routines. 1566 ** 1567 ** This object is used in only one place in the SQLite interface. 1568 ** A pointer to an instance of this object is the argument to 1569 ** [sqlite3_config()] when the configuration option is 1570 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1571 ** By creating an instance of this object 1572 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1573 ** during configuration, an application can specify an alternative 1574 ** memory allocation subsystem for SQLite to use for all of its 1575 ** dynamic memory needs. 1576 ** 1577 ** Note that SQLite comes with several [built-in memory allocators] 1578 ** that are perfectly adequate for the overwhelming majority of applications 1579 ** and that this object is only useful to a tiny minority of applications 1580 ** with specialized memory allocation requirements. This object is 1581 ** also used during testing of SQLite in order to specify an alternative 1582 ** memory allocator that simulates memory out-of-memory conditions in 1583 ** order to verify that SQLite recovers gracefully from such 1584 ** conditions. 1585 ** 1586 ** The xMalloc, xRealloc, and xFree methods must work like the 1587 ** malloc(), realloc() and free() functions from the standard C library. 1588 ** ^SQLite guarantees that the second argument to 1589 ** xRealloc is always a value returned by a prior call to xRoundup. 1590 ** 1591 ** xSize should return the allocated size of a memory allocation 1592 ** previously obtained from xMalloc or xRealloc. The allocated size 1593 ** is always at least as big as the requested size but may be larger. 1594 ** 1595 ** The xRoundup method returns what would be the allocated size of 1596 ** a memory allocation given a particular requested size. Most memory 1597 ** allocators round up memory allocations at least to the next multiple 1598 ** of 8. Some allocators round up to a larger multiple or to a power of 2. 1599 ** Every memory allocation request coming in through [sqlite3_malloc()] 1600 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1601 ** that causes the corresponding memory allocation to fail. 1602 ** 1603 ** The xInit method initializes the memory allocator. For example, 1604 ** it might allocate any require mutexes or initialize internal data 1605 ** structures. The xShutdown method is invoked (indirectly) by 1606 ** [sqlite3_shutdown()] and should deallocate any resources acquired 1607 ** by xInit. The pAppData pointer is used as the only parameter to 1608 ** xInit and xShutdown. 1609 ** 1610 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1611 ** the xInit method, so the xInit method need not be threadsafe. The 1612 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 1613 ** not need to be threadsafe either. For all other methods, SQLite 1614 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1615 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1616 ** it is by default) and so the methods are automatically serialized. 1617 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1618 ** methods must be threadsafe or else make their own arrangements for 1619 ** serialization. 1620 ** 1621 ** SQLite will never invoke xInit() more than once without an intervening 1622 ** call to xShutdown(). 1623 */ 1624 typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1625 struct sqlite3_mem_methods { 1626 void *(*xMalloc)(int); /* Memory allocation function */ 1627 void (*xFree)(void*); /* Free a prior allocation */ 1628 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1629 int (*xSize)(void*); /* Return the size of an allocation */ 1630 int (*xRoundup)(int); /* Round up request size to allocation size */ 1631 int (*xInit)(void*); /* Initialize the memory allocator */ 1632 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1633 void *pAppData; /* Argument to xInit() and xShutdown() */ 1634 }; 1635 1636 /* 1637 ** CAPI3REF: Configuration Options 1638 ** KEYWORDS: {configuration option} 1639 ** 1640 ** These constants are the available integer configuration options that 1641 ** can be passed as the first argument to the [sqlite3_config()] interface. 1642 ** 1643 ** New configuration options may be added in future releases of SQLite. 1644 ** Existing configuration options might be discontinued. Applications 1645 ** should check the return code from [sqlite3_config()] to make sure that 1646 ** the call worked. The [sqlite3_config()] interface will return a 1647 ** non-zero [error code] if a discontinued or unsupported configuration option 1648 ** is invoked. 1649 ** 1650 ** <dl> 1651 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1652 ** <dd>There are no arguments to this option. ^This option sets the 1653 ** [threading mode] to Single-thread. In other words, it disables 1654 ** all mutexing and puts SQLite into a mode where it can only be used 1655 ** by a single thread. ^If SQLite is compiled with 1656 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1657 ** it is not possible to change the [threading mode] from its default 1658 ** value of Single-thread and so [sqlite3_config()] will return 1659 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1660 ** configuration option.</dd> 1661 ** 1662 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1663 ** <dd>There are no arguments to this option. ^This option sets the 1664 ** [threading mode] to Multi-thread. In other words, it disables 1665 ** mutexing on [database connection] and [prepared statement] objects. 1666 ** The application is responsible for serializing access to 1667 ** [database connections] and [prepared statements]. But other mutexes 1668 ** are enabled so that SQLite will be safe to use in a multi-threaded 1669 ** environment as long as no two threads attempt to use the same 1670 ** [database connection] at the same time. ^If SQLite is compiled with 1671 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1672 ** it is not possible to set the Multi-thread [threading mode] and 1673 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1674 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1675 ** 1676 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1677 ** <dd>There are no arguments to this option. ^This option sets the 1678 ** [threading mode] to Serialized. In other words, this option enables 1679 ** all mutexes including the recursive 1680 ** mutexes on [database connection] and [prepared statement] objects. 1681 ** In this mode (which is the default when SQLite is compiled with 1682 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1683 ** to [database connections] and [prepared statements] so that the 1684 ** application is free to use the same [database connection] or the 1685 ** same [prepared statement] in different threads at the same time. 1686 ** ^If SQLite is compiled with 1687 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1688 ** it is not possible to set the Serialized [threading mode] and 1689 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1690 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1691 ** 1692 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1693 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1694 ** a pointer to an instance of the [sqlite3_mem_methods] structure. 1695 ** The argument specifies 1696 ** alternative low-level memory allocation routines to be used in place of 1697 ** the memory allocation routines built into SQLite.)^ ^SQLite makes 1698 ** its own private copy of the content of the [sqlite3_mem_methods] structure 1699 ** before the [sqlite3_config()] call returns.</dd> 1700 ** 1701 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1702 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1703 ** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1704 ** The [sqlite3_mem_methods] 1705 ** structure is filled with the currently defined memory allocation routines.)^ 1706 ** This option can be used to overload the default memory allocation 1707 ** routines with a wrapper that simulations memory allocation failure or 1708 ** tracks memory usage, for example. </dd> 1709 ** 1710 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1711 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1712 ** type int, interpreted as a boolean, which if true provides a hint to 1713 ** SQLite that it should avoid large memory allocations if possible. 1714 ** SQLite will run faster if it is free to make large memory allocations, 1715 ** but some application might prefer to run slower in exchange for 1716 ** guarantees about memory fragmentation that are possible if large 1717 ** allocations are avoided. This hint is normally off. 1718 ** </dd> 1719 ** 1720 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1721 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1722 ** interpreted as a boolean, which enables or disables the collection of 1723 ** memory allocation statistics. ^(When memory allocation statistics are 1724 ** disabled, the following SQLite interfaces become non-operational: 1725 ** <ul> 1726 ** <li> [sqlite3_memory_used()] 1727 ** <li> [sqlite3_memory_highwater()] 1728 ** <li> [sqlite3_soft_heap_limit64()] 1729 ** <li> [sqlite3_status64()] 1730 ** </ul>)^ 1731 ** ^Memory allocation statistics are enabled by default unless SQLite is 1732 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1733 ** allocation statistics are disabled by default. 1734 ** </dd> 1735 ** 1736 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1737 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1738 ** </dd> 1739 ** 1740 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1741 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1742 ** that SQLite can use for the database page cache with the default page 1743 ** cache implementation. 1744 ** This configuration option is a no-op if an application-define page 1745 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1746 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1747 ** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1748 ** and the number of cache lines (N). 1749 ** The sz argument should be the size of the largest database page 1750 ** (a power of two between 512 and 65536) plus some extra bytes for each 1751 ** page header. ^The number of extra bytes needed by the page header 1752 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1753 ** ^It is harmless, apart from the wasted memory, 1754 ** for the sz parameter to be larger than necessary. The pMem 1755 ** argument must be either a NULL pointer or a pointer to an 8-byte 1756 ** aligned block of memory of at least sz*N bytes, otherwise 1757 ** subsequent behavior is undefined. 1758 ** ^When pMem is not NULL, SQLite will strive to use the memory provided 1759 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1760 ** a page cache line is larger than sz bytes or if all of the pMem buffer 1761 ** is exhausted. 1762 ** ^If pMem is NULL and N is non-zero, then each database connection 1763 ** does an initial bulk allocation for page cache memory 1764 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1765 ** of -1024*N bytes if N is negative, . ^If additional 1766 ** page cache memory is needed beyond what is provided by the initial 1767 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1768 ** additional cache line. </dd> 1769 ** 1770 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1771 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1772 ** that SQLite will use for all of its dynamic memory allocation needs 1773 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1774 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1775 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1776 ** [SQLITE_ERROR] if invoked otherwise. 1777 ** ^There are three arguments to SQLITE_CONFIG_HEAP: 1778 ** An 8-byte aligned pointer to the memory, 1779 ** the number of bytes in the memory buffer, and the minimum allocation size. 1780 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1781 ** to using its default memory allocator (the system malloc() implementation), 1782 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1783 ** memory pointer is not NULL then the alternative memory 1784 ** allocator is engaged to handle all of SQLites memory allocation needs. 1785 ** The first pointer (the memory pointer) must be aligned to an 8-byte 1786 ** boundary or subsequent behavior of SQLite will be undefined. 1787 ** The minimum allocation size is capped at 2**12. Reasonable values 1788 ** for the minimum allocation size are 2**5 through 2**8.</dd> 1789 ** 1790 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1791 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1792 ** pointer to an instance of the [sqlite3_mutex_methods] structure. 1793 ** The argument specifies alternative low-level mutex routines to be used 1794 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1795 ** the content of the [sqlite3_mutex_methods] structure before the call to 1796 ** [sqlite3_config()] returns. ^If SQLite is compiled with 1797 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1798 ** the entire mutexing subsystem is omitted from the build and hence calls to 1799 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1800 ** return [SQLITE_ERROR].</dd> 1801 ** 1802 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1803 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1804 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1805 ** [sqlite3_mutex_methods] 1806 ** structure is filled with the currently defined mutex routines.)^ 1807 ** This option can be used to overload the default mutex allocation 1808 ** routines with a wrapper used to track mutex usage for performance 1809 ** profiling or testing, for example. ^If SQLite is compiled with 1810 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1811 ** the entire mutexing subsystem is omitted from the build and hence calls to 1812 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1813 ** return [SQLITE_ERROR].</dd> 1814 ** 1815 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1816 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1817 ** the default size of lookaside memory on each [database connection]. 1818 ** The first argument is the 1819 ** size of each lookaside buffer slot and the second is the number of 1820 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1821 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1822 ** option to [sqlite3_db_config()] can be used to change the lookaside 1823 ** configuration on individual connections.)^ </dd> 1824 ** 1825 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1826 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1827 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1828 ** the interface to a custom page cache implementation.)^ 1829 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1830 ** 1831 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1832 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1833 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1834 ** the current page cache implementation into that object.)^ </dd> 1835 ** 1836 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1837 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1838 ** global [error log]. 1839 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1840 ** function with a call signature of void(*)(void*,int,const char*), 1841 ** and a pointer to void. ^If the function pointer is not NULL, it is 1842 ** invoked by [sqlite3_log()] to process each logging event. ^If the 1843 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1844 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1845 ** passed through as the first parameter to the application-defined logger 1846 ** function whenever that function is invoked. ^The second parameter to 1847 ** the logger function is a copy of the first parameter to the corresponding 1848 ** [sqlite3_log()] call and is intended to be a [result code] or an 1849 ** [extended result code]. ^The third parameter passed to the logger is 1850 ** log message after formatting via [sqlite3_snprintf()]. 1851 ** The SQLite logging interface is not reentrant; the logger function 1852 ** supplied by the application must not invoke any SQLite interface. 1853 ** In a multi-threaded application, the application-defined logger 1854 ** function must be threadsafe. </dd> 1855 ** 1856 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1857 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1858 ** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1859 ** then URI handling is globally disabled.)^ ^If URI handling is globally 1860 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1861 ** [sqlite3_open16()] or 1862 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1863 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1864 ** connection is opened. ^If it is globally disabled, filenames are 1865 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1866 ** database connection is opened. ^(By default, URI handling is globally 1867 ** disabled. The default value may be changed by compiling with the 1868 ** [SQLITE_USE_URI] symbol defined.)^ 1869 ** 1870 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1871 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1872 ** argument which is interpreted as a boolean in order to enable or disable 1873 ** the use of covering indices for full table scans in the query optimizer. 1874 ** ^The default setting is determined 1875 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1876 ** if that compile-time option is omitted. 1877 ** The ability to disable the use of covering indices for full table scans 1878 ** is because some incorrectly coded legacy applications might malfunction 1879 ** when the optimization is enabled. Providing the ability to 1880 ** disable the optimization allows the older, buggy application code to work 1881 ** without change even with newer versions of SQLite. 1882 ** 1883 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1884 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1885 ** <dd> These options are obsolete and should not be used by new code. 1886 ** They are retained for backwards compatibility but are now no-ops. 1887 ** </dd> 1888 ** 1889 ** [[SQLITE_CONFIG_SQLLOG]] 1890 ** <dt>SQLITE_CONFIG_SQLLOG 1891 ** <dd>This option is only available if sqlite is compiled with the 1892 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1893 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1894 ** The second should be of type (void*). The callback is invoked by the library 1895 ** in three separate circumstances, identified by the value passed as the 1896 ** fourth parameter. If the fourth parameter is 0, then the database connection 1897 ** passed as the second argument has just been opened. The third argument 1898 ** points to a buffer containing the name of the main database file. If the 1899 ** fourth parameter is 1, then the SQL statement that the third parameter 1900 ** points to has just been executed. Or, if the fourth parameter is 2, then 1901 ** the connection being passed as the second parameter is being closed. The 1902 ** third parameter is passed NULL In this case. An example of using this 1903 ** configuration option can be seen in the "test_sqllog.c" source file in 1904 ** the canonical SQLite source tree.</dd> 1905 ** 1906 ** [[SQLITE_CONFIG_MMAP_SIZE]] 1907 ** <dt>SQLITE_CONFIG_MMAP_SIZE 1908 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1909 ** that are the default mmap size limit (the default setting for 1910 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1911 ** ^The default setting can be overridden by each database connection using 1912 ** either the [PRAGMA mmap_size] command, or by using the 1913 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1914 ** will be silently truncated if necessary so that it does not exceed the 1915 ** compile-time maximum mmap size set by the 1916 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1917 ** ^If either argument to this option is negative, then that argument is 1918 ** changed to its compile-time default. 1919 ** 1920 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1921 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1922 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1923 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1924 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1925 ** that specifies the maximum size of the created heap. 1926 ** 1927 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1928 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1929 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1930 ** is a pointer to an integer and writes into that integer the number of extra 1931 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1932 ** The amount of extra space required can change depending on the compiler, 1933 ** target platform, and SQLite version. 1934 ** 1935 ** [[SQLITE_CONFIG_PMASZ]] 1936 ** <dt>SQLITE_CONFIG_PMASZ 1937 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1938 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1939 ** sorter to that integer. The default minimum PMA Size is set by the 1940 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1941 ** to help with sort operations when multithreaded sorting 1942 ** is enabled (using the [PRAGMA threads] command) and the amount of content 1943 ** to be sorted exceeds the page size times the minimum of the 1944 ** [PRAGMA cache_size] setting and this value. 1945 ** 1946 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1947 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1948 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1949 ** becomes the [statement journal] spill-to-disk threshold. 1950 ** [Statement journals] are held in memory until their size (in bytes) 1951 ** exceeds this threshold, at which point they are written to disk. 1952 ** Or if the threshold is -1, statement journals are always held 1953 ** exclusively in memory. 1954 ** Since many statement journals never become large, setting the spill 1955 ** threshold to a value such as 64KiB can greatly reduce the amount of 1956 ** I/O required to support statement rollback. 1957 ** The default value for this setting is controlled by the 1958 ** [SQLITE_STMTJRNL_SPILL] compile-time option. 1959 ** 1960 ** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1961 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1962 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1963 ** of type (int) - the new value of the sorter-reference size threshold. 1964 ** Usually, when SQLite uses an external sort to order records according 1965 ** to an ORDER BY clause, all fields required by the caller are present in the 1966 ** sorted records. However, if SQLite determines based on the declared type 1967 ** of a table column that its values are likely to be very large - larger 1968 ** than the configured sorter-reference size threshold - then a reference 1969 ** is stored in each sorted record and the required column values loaded 1970 ** from the database as records are returned in sorted order. The default 1971 ** value for this option is to never use this optimization. Specifying a 1972 ** negative value for this option restores the default behaviour. 1973 ** This option is only available if SQLite is compiled with the 1974 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1975 ** </dl> 1976 */ 1977 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1978 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1979 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1980 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1981 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1982 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1983 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1984 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1985 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1986 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1987 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1988 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1989 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1990 #define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1991 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1992 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1993 #define SQLITE_CONFIG_URI 17 /* int */ 1994 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1995 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1996 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1997 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1998 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1999 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2000 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2001 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2002 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2003 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2004 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2005 2006 /* 2007 ** CAPI3REF: Database Connection Configuration Options 2008 ** 2009 ** These constants are the available integer configuration options that 2010 ** can be passed as the second argument to the [sqlite3_db_config()] interface. 2011 ** 2012 ** New configuration options may be added in future releases of SQLite. 2013 ** Existing configuration options might be discontinued. Applications 2014 ** should check the return code from [sqlite3_db_config()] to make sure that 2015 ** the call worked. ^The [sqlite3_db_config()] interface will return a 2016 ** non-zero [error code] if a discontinued or unsupported configuration option 2017 ** is invoked. 2018 ** 2019 ** <dl> 2020 ** [[SQLITE_DBCONFIG_LOOKASIDE]] 2021 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2022 ** <dd> ^This option takes three additional arguments that determine the 2023 ** [lookaside memory allocator] configuration for the [database connection]. 2024 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2025 ** pointer to a memory buffer to use for lookaside memory. 2026 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2027 ** may be NULL in which case SQLite will allocate the 2028 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2029 ** size of each lookaside buffer slot. ^The third argument is the number of 2030 ** slots. The size of the buffer in the first argument must be greater than 2031 ** or equal to the product of the second and third arguments. The buffer 2032 ** must be aligned to an 8-byte boundary. ^If the second argument to 2033 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2034 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2035 ** configuration for a database connection can only be changed when that 2036 ** connection is not currently using lookaside memory, or in other words 2037 ** when the "current value" returned by 2038 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2039 ** Any attempt to change the lookaside memory configuration when lookaside 2040 ** memory is in use leaves the configuration unchanged and returns 2041 ** [SQLITE_BUSY].)^</dd> 2042 ** 2043 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2044 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2045 ** <dd> ^This option is used to enable or disable the enforcement of 2046 ** [foreign key constraints]. There should be two additional arguments. 2047 ** The first argument is an integer which is 0 to disable FK enforcement, 2048 ** positive to enable FK enforcement or negative to leave FK enforcement 2049 ** unchanged. The second parameter is a pointer to an integer into which 2050 ** is written 0 or 1 to indicate whether FK enforcement is off or on 2051 ** following this call. The second parameter may be a NULL pointer, in 2052 ** which case the FK enforcement setting is not reported back. </dd> 2053 ** 2054 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2055 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2056 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2057 ** There should be two additional arguments. 2058 ** The first argument is an integer which is 0 to disable triggers, 2059 ** positive to enable triggers or negative to leave the setting unchanged. 2060 ** The second parameter is a pointer to an integer into which 2061 ** is written 0 or 1 to indicate whether triggers are disabled or enabled 2062 ** following this call. The second parameter may be a NULL pointer, in 2063 ** which case the trigger setting is not reported back. </dd> 2064 ** 2065 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2066 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2067 ** <dd> ^This option is used to enable or disable the two-argument 2068 ** version of the [fts3_tokenizer()] function which is part of the 2069 ** [FTS3] full-text search engine extension. 2070 ** There should be two additional arguments. 2071 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2072 ** positive to enable fts3_tokenizer() or negative to leave the setting 2073 ** unchanged. 2074 ** The second parameter is a pointer to an integer into which 2075 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2076 ** following this call. The second parameter may be a NULL pointer, in 2077 ** which case the new setting is not reported back. </dd> 2078 ** 2079 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2080 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2081 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2082 ** interface independently of the [load_extension()] SQL function. 2083 ** The [sqlite3_enable_load_extension()] API enables or disables both the 2084 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2085 ** There should be two additional arguments. 2086 ** When the first argument to this interface is 1, then only the C-API is 2087 ** enabled and the SQL function remains disabled. If the first argument to 2088 ** this interface is 0, then both the C-API and the SQL function are disabled. 2089 ** If the first argument is -1, then no changes are made to state of either the 2090 ** C-API or the SQL function. 2091 ** The second parameter is a pointer to an integer into which 2092 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2093 ** is disabled or enabled following this call. The second parameter may 2094 ** be a NULL pointer, in which case the new setting is not reported back. 2095 ** </dd> 2096 ** 2097 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2098 ** <dd> ^This option is used to change the name of the "main" database 2099 ** schema. ^The sole argument is a pointer to a constant UTF8 string 2100 ** which will become the new schema name in place of "main". ^SQLite 2101 ** does not make a copy of the new main schema name string, so the application 2102 ** must ensure that the argument passed into this DBCONFIG option is unchanged 2103 ** until after the database connection closes. 2104 ** </dd> 2105 ** 2106 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2107 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2108 ** <dd> Usually, when a database in wal mode is closed or detached from a 2109 ** database handle, SQLite checks if this will mean that there are now no 2110 ** connections at all to the database. If so, it performs a checkpoint 2111 ** operation before closing the connection. This option may be used to 2112 ** override this behaviour. The first parameter passed to this operation 2113 ** is an integer - positive to disable checkpoints-on-close, or zero (the 2114 ** default) to enable them, and negative to leave the setting unchanged. 2115 ** The second parameter is a pointer to an integer 2116 ** into which is written 0 or 1 to indicate whether checkpoints-on-close 2117 ** have been disabled - 0 if they are not disabled, 1 if they are. 2118 ** </dd> 2119 ** 2120 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2121 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2122 ** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2123 ** a single SQL query statement will always use the same algorithm regardless 2124 ** of values of [bound parameters].)^ The QPSG disables some query optimizations 2125 ** that look at the values of bound parameters, which can make some queries 2126 ** slower. But the QPSG has the advantage of more predictable behavior. With 2127 ** the QPSG active, SQLite will always use the same query plan in the field as 2128 ** was used during testing in the lab. 2129 ** The first argument to this setting is an integer which is 0 to disable 2130 ** the QPSG, positive to enable QPSG, or negative to leave the setting 2131 ** unchanged. The second parameter is a pointer to an integer into which 2132 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2133 ** following this call. 2134 ** </dd> 2135 ** 2136 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2137 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2138 ** include output for any operations performed by trigger programs. This 2139 ** option is used to set or clear (the default) a flag that governs this 2140 ** behavior. The first parameter passed to this operation is an integer - 2141 ** positive to enable output for trigger programs, or zero to disable it, 2142 ** or negative to leave the setting unchanged. 2143 ** The second parameter is a pointer to an integer into which is written 2144 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2145 ** it is not disabled, 1 if it is. 2146 ** </dd> 2147 ** 2148 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2149 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2150 ** [VACUUM] in order to reset a database back to an empty database 2151 ** with no schema and no content. The following process works even for 2152 ** a badly corrupted database file: 2153 ** <ol> 2154 ** <li> If the database connection is newly opened, make sure it has read the 2155 ** database schema by preparing then discarding some query against the 2156 ** database, or calling sqlite3_table_column_metadata(), ignoring any 2157 ** errors. This step is only necessary if the application desires to keep 2158 ** the database in WAL mode after the reset if it was in WAL mode before 2159 ** the reset. 2160 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2161 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2162 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2163 ** </ol> 2164 ** Because resetting a database is destructive and irreversible, the 2165 ** process requires the use of this obscure API and multiple steps to help 2166 ** ensure that it does not happen by accident. 2167 ** 2168 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2169 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2170 ** "defensive" flag for a database connection. When the defensive 2171 ** flag is enabled, language features that allow ordinary SQL to 2172 ** deliberately corrupt the database file are disabled. The disabled 2173 ** features include but are not limited to the following: 2174 ** <ul> 2175 ** <li> The [PRAGMA writable_schema=ON] statement. 2176 ** <li> Writes to the [sqlite_dbpage] virtual table. 2177 ** <li> Direct writes to [shadow tables]. 2178 ** </ul> 2179 ** </dd> 2180 ** </dl> 2181 */ 2182 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2183 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2184 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2185 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2186 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2187 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2188 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2189 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2190 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2191 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2192 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2193 #define SQLITE_DBCONFIG_MAX 1010 /* Largest DBCONFIG */ 2194 2195 /* 2196 ** CAPI3REF: Enable Or Disable Extended Result Codes 2197 ** METHOD: sqlite3 2198 ** 2199 ** ^The sqlite3_extended_result_codes() routine enables or disables the 2200 ** [extended result codes] feature of SQLite. ^The extended result 2201 ** codes are disabled by default for historical compatibility. 2202 */ 2203 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2204 2205 /* 2206 ** CAPI3REF: Last Insert Rowid 2207 ** METHOD: sqlite3 2208 ** 2209 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2210 ** has a unique 64-bit signed 2211 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2212 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2213 ** names are not also used by explicitly declared columns. ^If 2214 ** the table has a column of type [INTEGER PRIMARY KEY] then that column 2215 ** is another alias for the rowid. 2216 ** 2217 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2218 ** the most recent successful [INSERT] into a rowid table or [virtual table] 2219 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2220 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2221 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2222 ** zero. 2223 ** 2224 ** As well as being set automatically as rows are inserted into database 2225 ** tables, the value returned by this function may be set explicitly by 2226 ** [sqlite3_set_last_insert_rowid()] 2227 ** 2228 ** Some virtual table implementations may INSERT rows into rowid tables as 2229 ** part of committing a transaction (e.g. to flush data accumulated in memory 2230 ** to disk). In this case subsequent calls to this function return the rowid 2231 ** associated with these internal INSERT operations, which leads to 2232 ** unintuitive results. Virtual table implementations that do write to rowid 2233 ** tables in this way can avoid this problem by restoring the original 2234 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2235 ** control to the user. 2236 ** 2237 ** ^(If an [INSERT] occurs within a trigger then this routine will 2238 ** return the [rowid] of the inserted row as long as the trigger is 2239 ** running. Once the trigger program ends, the value returned 2240 ** by this routine reverts to what it was before the trigger was fired.)^ 2241 ** 2242 ** ^An [INSERT] that fails due to a constraint violation is not a 2243 ** successful [INSERT] and does not change the value returned by this 2244 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2245 ** and INSERT OR ABORT make no changes to the return value of this 2246 ** routine when their insertion fails. ^(When INSERT OR REPLACE 2247 ** encounters a constraint violation, it does not fail. The 2248 ** INSERT continues to completion after deleting rows that caused 2249 ** the constraint problem so INSERT OR REPLACE will always change 2250 ** the return value of this interface.)^ 2251 ** 2252 ** ^For the purposes of this routine, an [INSERT] is considered to 2253 ** be successful even if it is subsequently rolled back. 2254 ** 2255 ** This function is accessible to SQL statements via the 2256 ** [last_insert_rowid() SQL function]. 2257 ** 2258 ** If a separate thread performs a new [INSERT] on the same 2259 ** database connection while the [sqlite3_last_insert_rowid()] 2260 ** function is running and thus changes the last insert [rowid], 2261 ** then the value returned by [sqlite3_last_insert_rowid()] is 2262 ** unpredictable and might not equal either the old or the new 2263 ** last insert [rowid]. 2264 */ 2265 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2266 2267 /* 2268 ** CAPI3REF: Set the Last Insert Rowid value. 2269 ** METHOD: sqlite3 2270 ** 2271 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2272 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2273 ** without inserting a row into the database. 2274 */ 2275 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2276 2277 /* 2278 ** CAPI3REF: Count The Number Of Rows Modified 2279 ** METHOD: sqlite3 2280 ** 2281 ** ^This function returns the number of rows modified, inserted or 2282 ** deleted by the most recently completed INSERT, UPDATE or DELETE 2283 ** statement on the database connection specified by the only parameter. 2284 ** ^Executing any other type of SQL statement does not modify the value 2285 ** returned by this function. 2286 ** 2287 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2288 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2289 ** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2290 ** 2291 ** Changes to a view that are intercepted by 2292 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2293 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2294 ** DELETE statement run on a view is always zero. Only changes made to real 2295 ** tables are counted. 2296 ** 2297 ** Things are more complicated if the sqlite3_changes() function is 2298 ** executed while a trigger program is running. This may happen if the 2299 ** program uses the [changes() SQL function], or if some other callback 2300 ** function invokes sqlite3_changes() directly. Essentially: 2301 ** 2302 ** <ul> 2303 ** <li> ^(Before entering a trigger program the value returned by 2304 ** sqlite3_changes() function is saved. After the trigger program 2305 ** has finished, the original value is restored.)^ 2306 ** 2307 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2308 ** statement sets the value returned by sqlite3_changes() 2309 ** upon completion as normal. Of course, this value will not include 2310 ** any changes performed by sub-triggers, as the sqlite3_changes() 2311 ** value will be saved and restored after each sub-trigger has run.)^ 2312 ** </ul> 2313 ** 2314 ** ^This means that if the changes() SQL function (or similar) is used 2315 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2316 ** returns the value as set when the calling statement began executing. 2317 ** ^If it is used by the second or subsequent such statement within a trigger 2318 ** program, the value returned reflects the number of rows modified by the 2319 ** previous INSERT, UPDATE or DELETE statement within the same trigger. 2320 ** 2321 ** If a separate thread makes changes on the same database connection 2322 ** while [sqlite3_changes()] is running then the value returned 2323 ** is unpredictable and not meaningful. 2324 ** 2325 ** See also: 2326 ** <ul> 2327 ** <li> the [sqlite3_total_changes()] interface 2328 ** <li> the [count_changes pragma] 2329 ** <li> the [changes() SQL function] 2330 ** <li> the [data_version pragma] 2331 ** </ul> 2332 */ 2333 SQLITE_API int sqlite3_changes(sqlite3*); 2334 2335 /* 2336 ** CAPI3REF: Total Number Of Rows Modified 2337 ** METHOD: sqlite3 2338 ** 2339 ** ^This function returns the total number of rows inserted, modified or 2340 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2341 ** since the database connection was opened, including those executed as 2342 ** part of trigger programs. ^Executing any other type of SQL statement 2343 ** does not affect the value returned by sqlite3_total_changes(). 2344 ** 2345 ** ^Changes made as part of [foreign key actions] are included in the 2346 ** count, but those made as part of REPLACE constraint resolution are 2347 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2348 ** are not counted. 2349 ** 2350 ** This the [sqlite3_total_changes(D)] interface only reports the number 2351 ** of rows that changed due to SQL statement run against database 2352 ** connection D. Any changes by other database connections are ignored. 2353 ** To detect changes against a database file from other database 2354 ** connections use the [PRAGMA data_version] command or the 2355 ** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2356 ** 2357 ** If a separate thread makes changes on the same database connection 2358 ** while [sqlite3_total_changes()] is running then the value 2359 ** returned is unpredictable and not meaningful. 2360 ** 2361 ** See also: 2362 ** <ul> 2363 ** <li> the [sqlite3_changes()] interface 2364 ** <li> the [count_changes pragma] 2365 ** <li> the [changes() SQL function] 2366 ** <li> the [data_version pragma] 2367 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2368 ** </ul> 2369 */ 2370 SQLITE_API int sqlite3_total_changes(sqlite3*); 2371 2372 /* 2373 ** CAPI3REF: Interrupt A Long-Running Query 2374 ** METHOD: sqlite3 2375 ** 2376 ** ^This function causes any pending database operation to abort and 2377 ** return at its earliest opportunity. This routine is typically 2378 ** called in response to a user action such as pressing "Cancel" 2379 ** or Ctrl-C where the user wants a long query operation to halt 2380 ** immediately. 2381 ** 2382 ** ^It is safe to call this routine from a thread different from the 2383 ** thread that is currently running the database operation. But it 2384 ** is not safe to call this routine with a [database connection] that 2385 ** is closed or might close before sqlite3_interrupt() returns. 2386 ** 2387 ** ^If an SQL operation is very nearly finished at the time when 2388 ** sqlite3_interrupt() is called, then it might not have an opportunity 2389 ** to be interrupted and might continue to completion. 2390 ** 2391 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2392 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2393 ** that is inside an explicit transaction, then the entire transaction 2394 ** will be rolled back automatically. 2395 ** 2396 ** ^The sqlite3_interrupt(D) call is in effect until all currently running 2397 ** SQL statements on [database connection] D complete. ^Any new SQL statements 2398 ** that are started after the sqlite3_interrupt() call and before the 2399 ** running statements reaches zero are interrupted as if they had been 2400 ** running prior to the sqlite3_interrupt() call. ^New SQL statements 2401 ** that are started after the running statement count reaches zero are 2402 ** not effected by the sqlite3_interrupt(). 2403 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2404 ** SQL statements is a no-op and has no effect on SQL statements 2405 ** that are started after the sqlite3_interrupt() call returns. 2406 */ 2407 SQLITE_API void sqlite3_interrupt(sqlite3*); 2408 2409 /* 2410 ** CAPI3REF: Determine If An SQL Statement Is Complete 2411 ** 2412 ** These routines are useful during command-line input to determine if the 2413 ** currently entered text seems to form a complete SQL statement or 2414 ** if additional input is needed before sending the text into 2415 ** SQLite for parsing. ^These routines return 1 if the input string 2416 ** appears to be a complete SQL statement. ^A statement is judged to be 2417 ** complete if it ends with a semicolon token and is not a prefix of a 2418 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2419 ** string literals or quoted identifier names or comments are not 2420 ** independent tokens (they are part of the token in which they are 2421 ** embedded) and thus do not count as a statement terminator. ^Whitespace 2422 ** and comments that follow the final semicolon are ignored. 2423 ** 2424 ** ^These routines return 0 if the statement is incomplete. ^If a 2425 ** memory allocation fails, then SQLITE_NOMEM is returned. 2426 ** 2427 ** ^These routines do not parse the SQL statements thus 2428 ** will not detect syntactically incorrect SQL. 2429 ** 2430 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2431 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2432 ** automatically by sqlite3_complete16(). If that initialization fails, 2433 ** then the return value from sqlite3_complete16() will be non-zero 2434 ** regardless of whether or not the input SQL is complete.)^ 2435 ** 2436 ** The input to [sqlite3_complete()] must be a zero-terminated 2437 ** UTF-8 string. 2438 ** 2439 ** The input to [sqlite3_complete16()] must be a zero-terminated 2440 ** UTF-16 string in native byte order. 2441 */ 2442 SQLITE_API int sqlite3_complete(const char *sql); 2443 SQLITE_API int sqlite3_complete16(const void *sql); 2444 2445 /* 2446 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2447 ** KEYWORDS: {busy-handler callback} {busy handler} 2448 ** METHOD: sqlite3 2449 ** 2450 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2451 ** that might be invoked with argument P whenever 2452 ** an attempt is made to access a database table associated with 2453 ** [database connection] D when another thread 2454 ** or process has the table locked. 2455 ** The sqlite3_busy_handler() interface is used to implement 2456 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2457 ** 2458 ** ^If the busy callback is NULL, then [SQLITE_BUSY] 2459 ** is returned immediately upon encountering the lock. ^If the busy callback 2460 ** is not NULL, then the callback might be invoked with two arguments. 2461 ** 2462 ** ^The first argument to the busy handler is a copy of the void* pointer which 2463 ** is the third argument to sqlite3_busy_handler(). ^The second argument to 2464 ** the busy handler callback is the number of times that the busy handler has 2465 ** been invoked previously for the same locking event. ^If the 2466 ** busy callback returns 0, then no additional attempts are made to 2467 ** access the database and [SQLITE_BUSY] is returned 2468 ** to the application. 2469 ** ^If the callback returns non-zero, then another attempt 2470 ** is made to access the database and the cycle repeats. 2471 ** 2472 ** The presence of a busy handler does not guarantee that it will be invoked 2473 ** when there is lock contention. ^If SQLite determines that invoking the busy 2474 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2475 ** to the application instead of invoking the 2476 ** busy handler. 2477 ** Consider a scenario where one process is holding a read lock that 2478 ** it is trying to promote to a reserved lock and 2479 ** a second process is holding a reserved lock that it is trying 2480 ** to promote to an exclusive lock. The first process cannot proceed 2481 ** because it is blocked by the second and the second process cannot 2482 ** proceed because it is blocked by the first. If both processes 2483 ** invoke the busy handlers, neither will make any progress. Therefore, 2484 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2485 ** will induce the first process to release its read lock and allow 2486 ** the second process to proceed. 2487 ** 2488 ** ^The default busy callback is NULL. 2489 ** 2490 ** ^(There can only be a single busy handler defined for each 2491 ** [database connection]. Setting a new busy handler clears any 2492 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2493 ** or evaluating [PRAGMA busy_timeout=N] will change the 2494 ** busy handler and thus clear any previously set busy handler. 2495 ** 2496 ** The busy callback should not take any actions which modify the 2497 ** database connection that invoked the busy handler. In other words, 2498 ** the busy handler is not reentrant. Any such actions 2499 ** result in undefined behavior. 2500 ** 2501 ** A busy handler must not close the database connection 2502 ** or [prepared statement] that invoked the busy handler. 2503 */ 2504 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2505 2506 /* 2507 ** CAPI3REF: Set A Busy Timeout 2508 ** METHOD: sqlite3 2509 ** 2510 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2511 ** for a specified amount of time when a table is locked. ^The handler 2512 ** will sleep multiple times until at least "ms" milliseconds of sleeping 2513 ** have accumulated. ^After at least "ms" milliseconds of sleeping, 2514 ** the handler returns 0 which causes [sqlite3_step()] to return 2515 ** [SQLITE_BUSY]. 2516 ** 2517 ** ^Calling this routine with an argument less than or equal to zero 2518 ** turns off all busy handlers. 2519 ** 2520 ** ^(There can only be a single busy handler for a particular 2521 ** [database connection] at any given moment. If another busy handler 2522 ** was defined (using [sqlite3_busy_handler()]) prior to calling 2523 ** this routine, that other busy handler is cleared.)^ 2524 ** 2525 ** See also: [PRAGMA busy_timeout] 2526 */ 2527 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2528 2529 /* 2530 ** CAPI3REF: Convenience Routines For Running Queries 2531 ** METHOD: sqlite3 2532 ** 2533 ** This is a legacy interface that is preserved for backwards compatibility. 2534 ** Use of this interface is not recommended. 2535 ** 2536 ** Definition: A <b>result table</b> is memory data structure created by the 2537 ** [sqlite3_get_table()] interface. A result table records the 2538 ** complete query results from one or more queries. 2539 ** 2540 ** The table conceptually has a number of rows and columns. But 2541 ** these numbers are not part of the result table itself. These 2542 ** numbers are obtained separately. Let N be the number of rows 2543 ** and M be the number of columns. 2544 ** 2545 ** A result table is an array of pointers to zero-terminated UTF-8 strings. 2546 ** There are (N+1)*M elements in the array. The first M pointers point 2547 ** to zero-terminated strings that contain the names of the columns. 2548 ** The remaining entries all point to query results. NULL values result 2549 ** in NULL pointers. All other values are in their UTF-8 zero-terminated 2550 ** string representation as returned by [sqlite3_column_text()]. 2551 ** 2552 ** A result table might consist of one or more memory allocations. 2553 ** It is not safe to pass a result table directly to [sqlite3_free()]. 2554 ** A result table should be deallocated using [sqlite3_free_table()]. 2555 ** 2556 ** ^(As an example of the result table format, suppose a query result 2557 ** is as follows: 2558 ** 2559 ** <blockquote><pre> 2560 ** Name | Age 2561 ** ----------------------- 2562 ** Alice | 43 2563 ** Bob | 28 2564 ** Cindy | 21 2565 ** </pre></blockquote> 2566 ** 2567 ** There are two column (M==2) and three rows (N==3). Thus the 2568 ** result table has 8 entries. Suppose the result table is stored 2569 ** in an array names azResult. Then azResult holds this content: 2570 ** 2571 ** <blockquote><pre> 2572 ** azResult[0] = "Name"; 2573 ** azResult[1] = "Age"; 2574 ** azResult[2] = "Alice"; 2575 ** azResult[3] = "43"; 2576 ** azResult[4] = "Bob"; 2577 ** azResult[5] = "28"; 2578 ** azResult[6] = "Cindy"; 2579 ** azResult[7] = "21"; 2580 ** </pre></blockquote>)^ 2581 ** 2582 ** ^The sqlite3_get_table() function evaluates one or more 2583 ** semicolon-separated SQL statements in the zero-terminated UTF-8 2584 ** string of its 2nd parameter and returns a result table to the 2585 ** pointer given in its 3rd parameter. 2586 ** 2587 ** After the application has finished with the result from sqlite3_get_table(), 2588 ** it must pass the result table pointer to sqlite3_free_table() in order to 2589 ** release the memory that was malloced. Because of the way the 2590 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2591 ** function must not try to call [sqlite3_free()] directly. Only 2592 ** [sqlite3_free_table()] is able to release the memory properly and safely. 2593 ** 2594 ** The sqlite3_get_table() interface is implemented as a wrapper around 2595 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2596 ** to any internal data structures of SQLite. It uses only the public 2597 ** interface defined here. As a consequence, errors that occur in the 2598 ** wrapper layer outside of the internal [sqlite3_exec()] call are not 2599 ** reflected in subsequent calls to [sqlite3_errcode()] or 2600 ** [sqlite3_errmsg()]. 2601 */ 2602 SQLITE_API int sqlite3_get_table( 2603 sqlite3 *db, /* An open database */ 2604 const char *zSql, /* SQL to be evaluated */ 2605 char ***pazResult, /* Results of the query */ 2606 int *pnRow, /* Number of result rows written here */ 2607 int *pnColumn, /* Number of result columns written here */ 2608 char **pzErrmsg /* Error msg written here */ 2609 ); 2610 SQLITE_API void sqlite3_free_table(char **result); 2611 2612 /* 2613 ** CAPI3REF: Formatted String Printing Functions 2614 ** 2615 ** These routines are work-alikes of the "printf()" family of functions 2616 ** from the standard C library. 2617 ** These routines understand most of the common formatting options from 2618 ** the standard library printf() 2619 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2620 ** See the [built-in printf()] documentation for details. 2621 ** 2622 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2623 ** results into memory obtained from [sqlite3_malloc64()]. 2624 ** The strings returned by these two routines should be 2625 ** released by [sqlite3_free()]. ^Both routines return a 2626 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2627 ** memory to hold the resulting string. 2628 ** 2629 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2630 ** the standard C library. The result is written into the 2631 ** buffer supplied as the second parameter whose size is given by 2632 ** the first parameter. Note that the order of the 2633 ** first two parameters is reversed from snprintf().)^ This is an 2634 ** historical accident that cannot be fixed without breaking 2635 ** backwards compatibility. ^(Note also that sqlite3_snprintf() 2636 ** returns a pointer to its buffer instead of the number of 2637 ** characters actually written into the buffer.)^ We admit that 2638 ** the number of characters written would be a more useful return 2639 ** value but we cannot change the implementation of sqlite3_snprintf() 2640 ** now without breaking compatibility. 2641 ** 2642 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2643 ** guarantees that the buffer is always zero-terminated. ^The first 2644 ** parameter "n" is the total size of the buffer, including space for 2645 ** the zero terminator. So the longest string that can be completely 2646 ** written will be n-1 characters. 2647 ** 2648 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2649 ** 2650 ** See also: [built-in printf()], [printf() SQL function] 2651 */ 2652 SQLITE_API char *sqlite3_mprintf(const char*,...); 2653 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2654 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2655 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2656 2657 /* 2658 ** CAPI3REF: Memory Allocation Subsystem 2659 ** 2660 ** The SQLite core uses these three routines for all of its own 2661 ** internal memory allocation needs. "Core" in the previous sentence 2662 ** does not include operating-system specific VFS implementation. The 2663 ** Windows VFS uses native malloc() and free() for some operations. 2664 ** 2665 ** ^The sqlite3_malloc() routine returns a pointer to a block 2666 ** of memory at least N bytes in length, where N is the parameter. 2667 ** ^If sqlite3_malloc() is unable to obtain sufficient free 2668 ** memory, it returns a NULL pointer. ^If the parameter N to 2669 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2670 ** a NULL pointer. 2671 ** 2672 ** ^The sqlite3_malloc64(N) routine works just like 2673 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2674 ** of a signed 32-bit integer. 2675 ** 2676 ** ^Calling sqlite3_free() with a pointer previously returned 2677 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2678 ** that it might be reused. ^The sqlite3_free() routine is 2679 ** a no-op if is called with a NULL pointer. Passing a NULL pointer 2680 ** to sqlite3_free() is harmless. After being freed, memory 2681 ** should neither be read nor written. Even reading previously freed 2682 ** memory might result in a segmentation fault or other severe error. 2683 ** Memory corruption, a segmentation fault, or other severe error 2684 ** might result if sqlite3_free() is called with a non-NULL pointer that 2685 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2686 ** 2687 ** ^The sqlite3_realloc(X,N) interface attempts to resize a 2688 ** prior memory allocation X to be at least N bytes. 2689 ** ^If the X parameter to sqlite3_realloc(X,N) 2690 ** is a NULL pointer then its behavior is identical to calling 2691 ** sqlite3_malloc(N). 2692 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2693 ** negative then the behavior is exactly the same as calling 2694 ** sqlite3_free(X). 2695 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2696 ** of at least N bytes in size or NULL if insufficient memory is available. 2697 ** ^If M is the size of the prior allocation, then min(N,M) bytes 2698 ** of the prior allocation are copied into the beginning of buffer returned 2699 ** by sqlite3_realloc(X,N) and the prior allocation is freed. 2700 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2701 ** prior allocation is not freed. 2702 ** 2703 ** ^The sqlite3_realloc64(X,N) interfaces works the same as 2704 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2705 ** of a 32-bit signed integer. 2706 ** 2707 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2708 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2709 ** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2710 ** ^The value returned by sqlite3_msize(X) might be larger than the number 2711 ** of bytes requested when X was allocated. ^If X is a NULL pointer then 2712 ** sqlite3_msize(X) returns zero. If X points to something that is not 2713 ** the beginning of memory allocation, or if it points to a formerly 2714 ** valid memory allocation that has now been freed, then the behavior 2715 ** of sqlite3_msize(X) is undefined and possibly harmful. 2716 ** 2717 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2718 ** sqlite3_malloc64(), and sqlite3_realloc64() 2719 ** is always aligned to at least an 8 byte boundary, or to a 2720 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2721 ** option is used. 2722 ** 2723 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2724 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2725 ** implementation of these routines to be omitted. That capability 2726 ** is no longer provided. Only built-in memory allocators can be used. 2727 ** 2728 ** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2729 ** the system malloc() and free() directly when converting 2730 ** filenames between the UTF-8 encoding used by SQLite 2731 ** and whatever filename encoding is used by the particular Windows 2732 ** installation. Memory allocation errors were detected, but 2733 ** they were reported back as [SQLITE_CANTOPEN] or 2734 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2735 ** 2736 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2737 ** must be either NULL or else pointers obtained from a prior 2738 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2739 ** not yet been released. 2740 ** 2741 ** The application must not read or write any part of 2742 ** a block of memory after it has been released using 2743 ** [sqlite3_free()] or [sqlite3_realloc()]. 2744 */ 2745 SQLITE_API void *sqlite3_malloc(int); 2746 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 2747 SQLITE_API void *sqlite3_realloc(void*, int); 2748 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 2749 SQLITE_API void sqlite3_free(void*); 2750 SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 2751 2752 /* 2753 ** CAPI3REF: Memory Allocator Statistics 2754 ** 2755 ** SQLite provides these two interfaces for reporting on the status 2756 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2757 ** routines, which form the built-in memory allocation subsystem. 2758 ** 2759 ** ^The [sqlite3_memory_used()] routine returns the number of bytes 2760 ** of memory currently outstanding (malloced but not freed). 2761 ** ^The [sqlite3_memory_highwater()] routine returns the maximum 2762 ** value of [sqlite3_memory_used()] since the high-water mark 2763 ** was last reset. ^The values returned by [sqlite3_memory_used()] and 2764 ** [sqlite3_memory_highwater()] include any overhead 2765 ** added by SQLite in its implementation of [sqlite3_malloc()], 2766 ** but not overhead added by the any underlying system library 2767 ** routines that [sqlite3_malloc()] may call. 2768 ** 2769 ** ^The memory high-water mark is reset to the current value of 2770 ** [sqlite3_memory_used()] if and only if the parameter to 2771 ** [sqlite3_memory_highwater()] is true. ^The value returned 2772 ** by [sqlite3_memory_highwater(1)] is the high-water mark 2773 ** prior to the reset. 2774 */ 2775 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2776 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2777 2778 /* 2779 ** CAPI3REF: Pseudo-Random Number Generator 2780 ** 2781 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2782 ** select random [ROWID | ROWIDs] when inserting new records into a table that 2783 ** already uses the largest possible [ROWID]. The PRNG is also used for 2784 ** the build-in random() and randomblob() SQL functions. This interface allows 2785 ** applications to access the same PRNG for other purposes. 2786 ** 2787 ** ^A call to this routine stores N bytes of randomness into buffer P. 2788 ** ^The P parameter can be a NULL pointer. 2789 ** 2790 ** ^If this routine has not been previously called or if the previous 2791 ** call had N less than one or a NULL pointer for P, then the PRNG is 2792 ** seeded using randomness obtained from the xRandomness method of 2793 ** the default [sqlite3_vfs] object. 2794 ** ^If the previous call to this routine had an N of 1 or more and a 2795 ** non-NULL P then the pseudo-randomness is generated 2796 ** internally and without recourse to the [sqlite3_vfs] xRandomness 2797 ** method. 2798 */ 2799 SQLITE_API void sqlite3_randomness(int N, void *P); 2800 2801 /* 2802 ** CAPI3REF: Compile-Time Authorization Callbacks 2803 ** METHOD: sqlite3 2804 ** KEYWORDS: {authorizer callback} 2805 ** 2806 ** ^This routine registers an authorizer callback with a particular 2807 ** [database connection], supplied in the first argument. 2808 ** ^The authorizer callback is invoked as SQL statements are being compiled 2809 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2810 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2811 ** and [sqlite3_prepare16_v3()]. ^At various 2812 ** points during the compilation process, as logic is being created 2813 ** to perform various actions, the authorizer callback is invoked to 2814 ** see if those actions are allowed. ^The authorizer callback should 2815 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2816 ** specific action but allow the SQL statement to continue to be 2817 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2818 ** rejected with an error. ^If the authorizer callback returns 2819 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2820 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2821 ** the authorizer will fail with an error message. 2822 ** 2823 ** When the callback returns [SQLITE_OK], that means the operation 2824 ** requested is ok. ^When the callback returns [SQLITE_DENY], the 2825 ** [sqlite3_prepare_v2()] or equivalent call that triggered the 2826 ** authorizer will fail with an error message explaining that 2827 ** access is denied. 2828 ** 2829 ** ^The first parameter to the authorizer callback is a copy of the third 2830 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2831 ** to the callback is an integer [SQLITE_COPY | action code] that specifies 2832 ** the particular action to be authorized. ^The third through sixth parameters 2833 ** to the callback are either NULL pointers or zero-terminated strings 2834 ** that contain additional details about the action to be authorized. 2835 ** Applications must always be prepared to encounter a NULL pointer in any 2836 ** of the third through the sixth parameters of the authorization callback. 2837 ** 2838 ** ^If the action code is [SQLITE_READ] 2839 ** and the callback returns [SQLITE_IGNORE] then the 2840 ** [prepared statement] statement is constructed to substitute 2841 ** a NULL value in place of the table column that would have 2842 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2843 ** return can be used to deny an untrusted user access to individual 2844 ** columns of a table. 2845 ** ^When a table is referenced by a [SELECT] but no column values are 2846 ** extracted from that table (for example in a query like 2847 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2848 ** is invoked once for that table with a column name that is an empty string. 2849 ** ^If the action code is [SQLITE_DELETE] and the callback returns 2850 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2851 ** [truncate optimization] is disabled and all rows are deleted individually. 2852 ** 2853 ** An authorizer is used when [sqlite3_prepare | preparing] 2854 ** SQL statements from an untrusted source, to ensure that the SQL statements 2855 ** do not try to access data they are not allowed to see, or that they do not 2856 ** try to execute malicious statements that damage the database. For 2857 ** example, an application may allow a user to enter arbitrary 2858 ** SQL queries for evaluation by a database. But the application does 2859 ** not want the user to be able to make arbitrary changes to the 2860 ** database. An authorizer could then be put in place while the 2861 ** user-entered SQL is being [sqlite3_prepare | prepared] that 2862 ** disallows everything except [SELECT] statements. 2863 ** 2864 ** Applications that need to process SQL from untrusted sources 2865 ** might also consider lowering resource limits using [sqlite3_limit()] 2866 ** and limiting database size using the [max_page_count] [PRAGMA] 2867 ** in addition to using an authorizer. 2868 ** 2869 ** ^(Only a single authorizer can be in place on a database connection 2870 ** at a time. Each call to sqlite3_set_authorizer overrides the 2871 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2872 ** The authorizer is disabled by default. 2873 ** 2874 ** The authorizer callback must not do anything that will modify 2875 ** the database connection that invoked the authorizer callback. 2876 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2877 ** database connections for the meaning of "modify" in this paragraph. 2878 ** 2879 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2880 ** statement might be re-prepared during [sqlite3_step()] due to a 2881 ** schema change. Hence, the application should ensure that the 2882 ** correct authorizer callback remains in place during the [sqlite3_step()]. 2883 ** 2884 ** ^Note that the authorizer callback is invoked only during 2885 ** [sqlite3_prepare()] or its variants. Authorization is not 2886 ** performed during statement evaluation in [sqlite3_step()], unless 2887 ** as stated in the previous paragraph, sqlite3_step() invokes 2888 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2889 */ 2890 SQLITE_API int sqlite3_set_authorizer( 2891 sqlite3*, 2892 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2893 void *pUserData 2894 ); 2895 2896 /* 2897 ** CAPI3REF: Authorizer Return Codes 2898 ** 2899 ** The [sqlite3_set_authorizer | authorizer callback function] must 2900 ** return either [SQLITE_OK] or one of these two constants in order 2901 ** to signal SQLite whether or not the action is permitted. See the 2902 ** [sqlite3_set_authorizer | authorizer documentation] for additional 2903 ** information. 2904 ** 2905 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2906 ** returned from the [sqlite3_vtab_on_conflict()] interface. 2907 */ 2908 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2909 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2910 2911 /* 2912 ** CAPI3REF: Authorizer Action Codes 2913 ** 2914 ** The [sqlite3_set_authorizer()] interface registers a callback function 2915 ** that is invoked to authorize certain SQL statement actions. The 2916 ** second parameter to the callback is an integer code that specifies 2917 ** what action is being authorized. These are the integer action codes that 2918 ** the authorizer callback may be passed. 2919 ** 2920 ** These action code values signify what kind of operation is to be 2921 ** authorized. The 3rd and 4th parameters to the authorization 2922 ** callback function will be parameters or NULL depending on which of these 2923 ** codes is used as the second parameter. ^(The 5th parameter to the 2924 ** authorizer callback is the name of the database ("main", "temp", 2925 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2926 ** is the name of the inner-most trigger or view that is responsible for 2927 ** the access attempt or NULL if this access attempt is directly from 2928 ** top-level SQL code. 2929 */ 2930 /******************************************* 3rd ************ 4th ***********/ 2931 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2932 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2933 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2934 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2935 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2936 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2937 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2938 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2939 #define SQLITE_DELETE 9 /* Table Name NULL */ 2940 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2941 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2942 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2943 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2944 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2945 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2946 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2947 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2948 #define SQLITE_INSERT 18 /* Table Name NULL */ 2949 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2950 #define SQLITE_READ 20 /* Table Name Column Name */ 2951 #define SQLITE_SELECT 21 /* NULL NULL */ 2952 #define SQLITE_TRANSACTION 22 /* Operation NULL */ 2953 #define SQLITE_UPDATE 23 /* Table Name Column Name */ 2954 #define SQLITE_ATTACH 24 /* Filename NULL */ 2955 #define SQLITE_DETACH 25 /* Database Name NULL */ 2956 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2957 #define SQLITE_REINDEX 27 /* Index Name NULL */ 2958 #define SQLITE_ANALYZE 28 /* Table Name NULL */ 2959 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2960 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2961 #define SQLITE_FUNCTION 31 /* NULL Function Name */ 2962 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2963 #define SQLITE_COPY 0 /* No longer used */ 2964 #define SQLITE_RECURSIVE 33 /* NULL NULL */ 2965 2966 /* 2967 ** CAPI3REF: Tracing And Profiling Functions 2968 ** METHOD: sqlite3 2969 ** 2970 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2971 ** instead of the routines described here. 2972 ** 2973 ** These routines register callback functions that can be used for 2974 ** tracing and profiling the execution of SQL statements. 2975 ** 2976 ** ^The callback function registered by sqlite3_trace() is invoked at 2977 ** various times when an SQL statement is being run by [sqlite3_step()]. 2978 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2979 ** SQL statement text as the statement first begins executing. 2980 ** ^(Additional sqlite3_trace() callbacks might occur 2981 ** as each triggered subprogram is entered. The callbacks for triggers 2982 ** contain a UTF-8 SQL comment that identifies the trigger.)^ 2983 ** 2984 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2985 ** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2986 ** 2987 ** ^The callback function registered by sqlite3_profile() is invoked 2988 ** as each SQL statement finishes. ^The profile callback contains 2989 ** the original statement text and an estimate of wall-clock time 2990 ** of how long that statement took to run. ^The profile callback 2991 ** time is in units of nanoseconds, however the current implementation 2992 ** is only capable of millisecond resolution so the six least significant 2993 ** digits in the time are meaningless. Future versions of SQLite 2994 ** might provide greater resolution on the profiler callback. The 2995 ** sqlite3_profile() function is considered experimental and is 2996 ** subject to change in future versions of SQLite. 2997 */ 2998 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2999 void(*xTrace)(void*,const char*), void*); 3000 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3001 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3002 3003 /* 3004 ** CAPI3REF: SQL Trace Event Codes 3005 ** KEYWORDS: SQLITE_TRACE 3006 ** 3007 ** These constants identify classes of events that can be monitored 3008 ** using the [sqlite3_trace_v2()] tracing logic. The M argument 3009 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3010 ** the following constants. ^The first argument to the trace callback 3011 ** is one of the following constants. 3012 ** 3013 ** New tracing constants may be added in future releases. 3014 ** 3015 ** ^A trace callback has four arguments: xCallback(T,C,P,X). 3016 ** ^The T argument is one of the integer type codes above. 3017 ** ^The C argument is a copy of the context pointer passed in as the 3018 ** fourth argument to [sqlite3_trace_v2()]. 3019 ** The P and X arguments are pointers whose meanings depend on T. 3020 ** 3021 ** <dl> 3022 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3023 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3024 ** first begins running and possibly at other times during the 3025 ** execution of the prepared statement, such as at the start of each 3026 ** trigger subprogram. ^The P argument is a pointer to the 3027 ** [prepared statement]. ^The X argument is a pointer to a string which 3028 ** is the unexpanded SQL text of the prepared statement or an SQL comment 3029 ** that indicates the invocation of a trigger. ^The callback can compute 3030 ** the same text that would have been returned by the legacy [sqlite3_trace()] 3031 ** interface by using the X argument when X begins with "--" and invoking 3032 ** [sqlite3_expanded_sql(P)] otherwise. 3033 ** 3034 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3035 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3036 ** information as is provided by the [sqlite3_profile()] callback. 3037 ** ^The P argument is a pointer to the [prepared statement] and the 3038 ** X argument points to a 64-bit integer which is the estimated of 3039 ** the number of nanosecond that the prepared statement took to run. 3040 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3041 ** 3042 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3043 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3044 ** statement generates a single row of result. 3045 ** ^The P argument is a pointer to the [prepared statement] and the 3046 ** X argument is unused. 3047 ** 3048 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3049 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3050 ** connection closes. 3051 ** ^The P argument is a pointer to the [database connection] object 3052 ** and the X argument is unused. 3053 ** </dl> 3054 */ 3055 #define SQLITE_TRACE_STMT 0x01 3056 #define SQLITE_TRACE_PROFILE 0x02 3057 #define SQLITE_TRACE_ROW 0x04 3058 #define SQLITE_TRACE_CLOSE 0x08 3059 3060 /* 3061 ** CAPI3REF: SQL Trace Hook 3062 ** METHOD: sqlite3 3063 ** 3064 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3065 ** function X against [database connection] D, using property mask M 3066 ** and context pointer P. ^If the X callback is 3067 ** NULL or if the M mask is zero, then tracing is disabled. The 3068 ** M argument should be the bitwise OR-ed combination of 3069 ** zero or more [SQLITE_TRACE] constants. 3070 ** 3071 ** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3072 ** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3073 ** 3074 ** ^The X callback is invoked whenever any of the events identified by 3075 ** mask M occur. ^The integer return value from the callback is currently 3076 ** ignored, though this may change in future releases. Callback 3077 ** implementations should return zero to ensure future compatibility. 3078 ** 3079 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3080 ** ^The T argument is one of the [SQLITE_TRACE] 3081 ** constants to indicate why the callback was invoked. 3082 ** ^The C argument is a copy of the context pointer. 3083 ** The P and X arguments are pointers whose meanings depend on T. 3084 ** 3085 ** The sqlite3_trace_v2() interface is intended to replace the legacy 3086 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3087 ** are deprecated. 3088 */ 3089 SQLITE_API int sqlite3_trace_v2( 3090 sqlite3*, 3091 unsigned uMask, 3092 int(*xCallback)(unsigned,void*,void*,void*), 3093 void *pCtx 3094 ); 3095 3096 /* 3097 ** CAPI3REF: Query Progress Callbacks 3098 ** METHOD: sqlite3 3099 ** 3100 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3101 ** function X to be invoked periodically during long running calls to 3102 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3103 ** database connection D. An example use for this 3104 ** interface is to keep a GUI updated during a large query. 3105 ** 3106 ** ^The parameter P is passed through as the only parameter to the 3107 ** callback function X. ^The parameter N is the approximate number of 3108 ** [virtual machine instructions] that are evaluated between successive 3109 ** invocations of the callback X. ^If N is less than one then the progress 3110 ** handler is disabled. 3111 ** 3112 ** ^Only a single progress handler may be defined at one time per 3113 ** [database connection]; setting a new progress handler cancels the 3114 ** old one. ^Setting parameter X to NULL disables the progress handler. 3115 ** ^The progress handler is also disabled by setting N to a value less 3116 ** than 1. 3117 ** 3118 ** ^If the progress callback returns non-zero, the operation is 3119 ** interrupted. This feature can be used to implement a 3120 ** "Cancel" button on a GUI progress dialog box. 3121 ** 3122 ** The progress handler callback must not do anything that will modify 3123 ** the database connection that invoked the progress handler. 3124 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3125 ** database connections for the meaning of "modify" in this paragraph. 3126 ** 3127 */ 3128 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3129 3130 /* 3131 ** CAPI3REF: Opening A New Database Connection 3132 ** CONSTRUCTOR: sqlite3 3133 ** 3134 ** ^These routines open an SQLite database file as specified by the 3135 ** filename argument. ^The filename argument is interpreted as UTF-8 for 3136 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3137 ** order for sqlite3_open16(). ^(A [database connection] handle is usually 3138 ** returned in *ppDb, even if an error occurs. The only exception is that 3139 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3140 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3141 ** object.)^ ^(If the database is opened (and/or created) successfully, then 3142 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3143 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3144 ** an English language description of the error following a failure of any 3145 ** of the sqlite3_open() routines. 3146 ** 3147 ** ^The default encoding will be UTF-8 for databases created using 3148 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3149 ** created using sqlite3_open16() will be UTF-16 in the native byte order. 3150 ** 3151 ** Whether or not an error occurs when it is opened, resources 3152 ** associated with the [database connection] handle should be released by 3153 ** passing it to [sqlite3_close()] when it is no longer required. 3154 ** 3155 ** The sqlite3_open_v2() interface works like sqlite3_open() 3156 ** except that it accepts two additional parameters for additional control 3157 ** over the new database connection. ^(The flags parameter to 3158 ** sqlite3_open_v2() can take one of 3159 ** the following three values, optionally combined with the 3160 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3161 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3162 ** 3163 ** <dl> 3164 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3165 ** <dd>The database is opened in read-only mode. If the database does not 3166 ** already exist, an error is returned.</dd>)^ 3167 ** 3168 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3169 ** <dd>The database is opened for reading and writing if possible, or reading 3170 ** only if the file is write protected by the operating system. In either 3171 ** case the database must already exist, otherwise an error is returned.</dd>)^ 3172 ** 3173 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3174 ** <dd>The database is opened for reading and writing, and is created if 3175 ** it does not already exist. This is the behavior that is always used for 3176 ** sqlite3_open() and sqlite3_open16().</dd>)^ 3177 ** </dl> 3178 ** 3179 ** If the 3rd parameter to sqlite3_open_v2() is not one of the 3180 ** combinations shown above optionally combined with other 3181 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3182 ** then the behavior is undefined. 3183 ** 3184 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3185 ** opens in the multi-thread [threading mode] as long as the single-thread 3186 ** mode has not been set at compile-time or start-time. ^If the 3187 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3188 ** in the serialized [threading mode] unless single-thread was 3189 ** previously selected at compile-time or start-time. 3190 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3191 ** eligible to use [shared cache mode], regardless of whether or not shared 3192 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3193 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3194 ** participate in [shared cache mode] even if it is enabled. 3195 ** 3196 ** ^The fourth parameter to sqlite3_open_v2() is the name of the 3197 ** [sqlite3_vfs] object that defines the operating system interface that 3198 ** the new database connection should use. ^If the fourth parameter is 3199 ** a NULL pointer then the default [sqlite3_vfs] object is used. 3200 ** 3201 ** ^If the filename is ":memory:", then a private, temporary in-memory database 3202 ** is created for the connection. ^This in-memory database will vanish when 3203 ** the database connection is closed. Future versions of SQLite might 3204 ** make use of additional special filenames that begin with the ":" character. 3205 ** It is recommended that when a database filename actually does begin with 3206 ** a ":" character you should prefix the filename with a pathname such as 3207 ** "./" to avoid ambiguity. 3208 ** 3209 ** ^If the filename is an empty string, then a private, temporary 3210 ** on-disk database will be created. ^This private database will be 3211 ** automatically deleted as soon as the database connection is closed. 3212 ** 3213 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3214 ** 3215 ** ^If [URI filename] interpretation is enabled, and the filename argument 3216 ** begins with "file:", then the filename is interpreted as a URI. ^URI 3217 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3218 ** set in the third argument to sqlite3_open_v2(), or if it has 3219 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3220 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3221 ** URI filename interpretation is turned off 3222 ** by default, but future releases of SQLite might enable URI filename 3223 ** interpretation by default. See "[URI filenames]" for additional 3224 ** information. 3225 ** 3226 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3227 ** authority, then it must be either an empty string or the string 3228 ** "localhost". ^If the authority is not an empty string or "localhost", an 3229 ** error is returned to the caller. ^The fragment component of a URI, if 3230 ** present, is ignored. 3231 ** 3232 ** ^SQLite uses the path component of the URI as the name of the disk file 3233 ** which contains the database. ^If the path begins with a '/' character, 3234 ** then it is interpreted as an absolute path. ^If the path does not begin 3235 ** with a '/' (meaning that the authority section is omitted from the URI) 3236 ** then the path is interpreted as a relative path. 3237 ** ^(On windows, the first component of an absolute path 3238 ** is a drive specification (e.g. "C:").)^ 3239 ** 3240 ** [[core URI query parameters]] 3241 ** The query component of a URI may contain parameters that are interpreted 3242 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3243 ** SQLite and its built-in [VFSes] interpret the 3244 ** following query parameters: 3245 ** 3246 ** <ul> 3247 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3248 ** a VFS object that provides the operating system interface that should 3249 ** be used to access the database file on disk. ^If this option is set to 3250 ** an empty string the default VFS object is used. ^Specifying an unknown 3251 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3252 ** present, then the VFS specified by the option takes precedence over 3253 ** the value passed as the fourth parameter to sqlite3_open_v2(). 3254 ** 3255 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3256 ** "rwc", or "memory". Attempting to set it to any other value is 3257 ** an error)^. 3258 ** ^If "ro" is specified, then the database is opened for read-only 3259 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3260 ** third argument to sqlite3_open_v2(). ^If the mode option is set to 3261 ** "rw", then the database is opened for read-write (but not create) 3262 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3263 ** been set. ^Value "rwc" is equivalent to setting both 3264 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3265 ** set to "memory" then a pure [in-memory database] that never reads 3266 ** or writes from disk is used. ^It is an error to specify a value for 3267 ** the mode parameter that is less restrictive than that specified by 3268 ** the flags passed in the third parameter to sqlite3_open_v2(). 3269 ** 3270 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3271 ** "private". ^Setting it to "shared" is equivalent to setting the 3272 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3273 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3274 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3275 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3276 ** a URI filename, its value overrides any behavior requested by setting 3277 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3278 ** 3279 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3280 ** [powersafe overwrite] property does or does not apply to the 3281 ** storage media on which the database file resides. 3282 ** 3283 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3284 ** which if set disables file locking in rollback journal modes. This 3285 ** is useful for accessing a database on a filesystem that does not 3286 ** support locking. Caution: Database corruption might result if two 3287 ** or more processes write to the same database and any one of those 3288 ** processes uses nolock=1. 3289 ** 3290 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3291 ** parameter that indicates that the database file is stored on 3292 ** read-only media. ^When immutable is set, SQLite assumes that the 3293 ** database file cannot be changed, even by a process with higher 3294 ** privilege, and so the database is opened read-only and all locking 3295 ** and change detection is disabled. Caution: Setting the immutable 3296 ** property on a database file that does in fact change can result 3297 ** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3298 ** See also: [SQLITE_IOCAP_IMMUTABLE]. 3299 ** 3300 ** </ul> 3301 ** 3302 ** ^Specifying an unknown parameter in the query component of a URI is not an 3303 ** error. Future versions of SQLite might understand additional query 3304 ** parameters. See "[query parameters with special meaning to SQLite]" for 3305 ** additional information. 3306 ** 3307 ** [[URI filename examples]] <h3>URI filename examples</h3> 3308 ** 3309 ** <table border="1" align=center cellpadding=5> 3310 ** <tr><th> URI filenames <th> Results 3311 ** <tr><td> file:data.db <td> 3312 ** Open the file "data.db" in the current directory. 3313 ** <tr><td> file:/home/fred/data.db<br> 3314 ** file:///home/fred/data.db <br> 3315 ** file://localhost/home/fred/data.db <br> <td> 3316 ** Open the database file "/home/fred/data.db". 3317 ** <tr><td> file://darkstar/home/fred/data.db <td> 3318 ** An error. "darkstar" is not a recognized authority. 3319 ** <tr><td style="white-space:nowrap"> 3320 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3321 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3322 ** C:. Note that the %20 escaping in this example is not strictly 3323 ** necessary - space characters can be used literally 3324 ** in URI filenames. 3325 ** <tr><td> file:data.db?mode=ro&cache=private <td> 3326 ** Open file "data.db" in the current directory for read-only access. 3327 ** Regardless of whether or not shared-cache mode is enabled by 3328 ** default, use a private cache. 3329 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3330 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3331 ** that uses dot-files in place of posix advisory locking. 3332 ** <tr><td> file:data.db?mode=readonly <td> 3333 ** An error. "readonly" is not a valid option for the "mode" parameter. 3334 ** </table> 3335 ** 3336 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3337 ** query components of a URI. A hexadecimal escape sequence consists of a 3338 ** percent sign - "%" - followed by exactly two hexadecimal digits 3339 ** specifying an octet value. ^Before the path or query components of a 3340 ** URI filename are interpreted, they are encoded using UTF-8 and all 3341 ** hexadecimal escape sequences replaced by a single byte containing the 3342 ** corresponding octet. If this process generates an invalid UTF-8 encoding, 3343 ** the results are undefined. 3344 ** 3345 ** <b>Note to Windows users:</b> The encoding used for the filename argument 3346 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3347 ** codepage is currently defined. Filenames containing international 3348 ** characters must be converted to UTF-8 prior to passing them into 3349 ** sqlite3_open() or sqlite3_open_v2(). 3350 ** 3351 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3352 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3353 ** features that require the use of temporary files may fail. 3354 ** 3355 ** See also: [sqlite3_temp_directory] 3356 */ 3357 SQLITE_API int sqlite3_open( 3358 const char *filename, /* Database filename (UTF-8) */ 3359 sqlite3 **ppDb /* OUT: SQLite db handle */ 3360 ); 3361 SQLITE_API int sqlite3_open16( 3362 const void *filename, /* Database filename (UTF-16) */ 3363 sqlite3 **ppDb /* OUT: SQLite db handle */ 3364 ); 3365 SQLITE_API int sqlite3_open_v2( 3366 const char *filename, /* Database filename (UTF-8) */ 3367 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3368 int flags, /* Flags */ 3369 const char *zVfs /* Name of VFS module to use */ 3370 ); 3371 3372 /* 3373 ** CAPI3REF: Obtain Values For URI Parameters 3374 ** 3375 ** These are utility routines, useful to VFS implementations, that check 3376 ** to see if a database file was a URI that contained a specific query 3377 ** parameter, and if so obtains the value of that query parameter. 3378 ** 3379 ** If F is the database filename pointer passed into the xOpen() method of 3380 ** a VFS implementation when the flags parameter to xOpen() has one or 3381 ** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3382 ** P is the name of the query parameter, then 3383 ** sqlite3_uri_parameter(F,P) returns the value of the P 3384 ** parameter if it exists or a NULL pointer if P does not appear as a 3385 ** query parameter on F. If P is a query parameter of F 3386 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3387 ** a pointer to an empty string. 3388 ** 3389 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3390 ** parameter and returns true (1) or false (0) according to the value 3391 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3392 ** value of query parameter P is one of "yes", "true", or "on" in any 3393 ** case or if the value begins with a non-zero number. The 3394 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3395 ** query parameter P is one of "no", "false", or "off" in any case or 3396 ** if the value begins with a numeric zero. If P is not a query 3397 ** parameter on F or if the value of P is does not match any of the 3398 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3399 ** 3400 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3401 ** 64-bit signed integer and returns that integer, or D if P does not 3402 ** exist. If the value of P is something other than an integer, then 3403 ** zero is returned. 3404 ** 3405 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3406 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3407 ** is not a database file pathname pointer that SQLite passed into the xOpen 3408 ** VFS method, then the behavior of this routine is undefined and probably 3409 ** undesirable. 3410 */ 3411 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3412 SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3413 SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3414 3415 3416 /* 3417 ** CAPI3REF: Error Codes And Messages 3418 ** METHOD: sqlite3 3419 ** 3420 ** ^If the most recent sqlite3_* API call associated with 3421 ** [database connection] D failed, then the sqlite3_errcode(D) interface 3422 ** returns the numeric [result code] or [extended result code] for that 3423 ** API call. 3424 ** ^The sqlite3_extended_errcode() 3425 ** interface is the same except that it always returns the 3426 ** [extended result code] even when extended result codes are 3427 ** disabled. 3428 ** 3429 ** The values returned by sqlite3_errcode() and/or 3430 ** sqlite3_extended_errcode() might change with each API call. 3431 ** Except, there are some interfaces that are guaranteed to never 3432 ** change the value of the error code. The error-code preserving 3433 ** interfaces are: 3434 ** 3435 ** <ul> 3436 ** <li> sqlite3_errcode() 3437 ** <li> sqlite3_extended_errcode() 3438 ** <li> sqlite3_errmsg() 3439 ** <li> sqlite3_errmsg16() 3440 ** </ul> 3441 ** 3442 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3443 ** text that describes the error, as either UTF-8 or UTF-16 respectively. 3444 ** ^(Memory to hold the error message string is managed internally. 3445 ** The application does not need to worry about freeing the result. 3446 ** However, the error string might be overwritten or deallocated by 3447 ** subsequent calls to other SQLite interface functions.)^ 3448 ** 3449 ** ^The sqlite3_errstr() interface returns the English-language text 3450 ** that describes the [result code], as UTF-8. 3451 ** ^(Memory to hold the error message string is managed internally 3452 ** and must not be freed by the application)^. 3453 ** 3454 ** When the serialized [threading mode] is in use, it might be the 3455 ** case that a second error occurs on a separate thread in between 3456 ** the time of the first error and the call to these interfaces. 3457 ** When that happens, the second error will be reported since these 3458 ** interfaces always report the most recent result. To avoid 3459 ** this, each thread can obtain exclusive use of the [database connection] D 3460 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3461 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3462 ** all calls to the interfaces listed here are completed. 3463 ** 3464 ** If an interface fails with SQLITE_MISUSE, that means the interface 3465 ** was invoked incorrectly by the application. In that case, the 3466 ** error code and message may or may not be set. 3467 */ 3468 SQLITE_API int sqlite3_errcode(sqlite3 *db); 3469 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3470 SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3471 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3472 SQLITE_API const char *sqlite3_errstr(int); 3473 3474 /* 3475 ** CAPI3REF: Prepared Statement Object 3476 ** KEYWORDS: {prepared statement} {prepared statements} 3477 ** 3478 ** An instance of this object represents a single SQL statement that 3479 ** has been compiled into binary form and is ready to be evaluated. 3480 ** 3481 ** Think of each SQL statement as a separate computer program. The 3482 ** original SQL text is source code. A prepared statement object 3483 ** is the compiled object code. All SQL must be converted into a 3484 ** prepared statement before it can be run. 3485 ** 3486 ** The life-cycle of a prepared statement object usually goes like this: 3487 ** 3488 ** <ol> 3489 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3490 ** <li> Bind values to [parameters] using the sqlite3_bind_*() 3491 ** interfaces. 3492 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3493 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3494 ** to step 2. Do this zero or more times. 3495 ** <li> Destroy the object using [sqlite3_finalize()]. 3496 ** </ol> 3497 */ 3498 typedef struct sqlite3_stmt sqlite3_stmt; 3499 3500 /* 3501 ** CAPI3REF: Run-time Limits 3502 ** METHOD: sqlite3 3503 ** 3504 ** ^(This interface allows the size of various constructs to be limited 3505 ** on a connection by connection basis. The first parameter is the 3506 ** [database connection] whose limit is to be set or queried. The 3507 ** second parameter is one of the [limit categories] that define a 3508 ** class of constructs to be size limited. The third parameter is the 3509 ** new limit for that construct.)^ 3510 ** 3511 ** ^If the new limit is a negative number, the limit is unchanged. 3512 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3513 ** [limits | hard upper bound] 3514 ** set at compile-time by a C preprocessor macro called 3515 ** [limits | SQLITE_MAX_<i>NAME</i>]. 3516 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3517 ** ^Attempts to increase a limit above its hard upper bound are 3518 ** silently truncated to the hard upper bound. 3519 ** 3520 ** ^Regardless of whether or not the limit was changed, the 3521 ** [sqlite3_limit()] interface returns the prior value of the limit. 3522 ** ^Hence, to find the current value of a limit without changing it, 3523 ** simply invoke this interface with the third parameter set to -1. 3524 ** 3525 ** Run-time limits are intended for use in applications that manage 3526 ** both their own internal database and also databases that are controlled 3527 ** by untrusted external sources. An example application might be a 3528 ** web browser that has its own databases for storing history and 3529 ** separate databases controlled by JavaScript applications downloaded 3530 ** off the Internet. The internal databases can be given the 3531 ** large, default limits. Databases managed by external sources can 3532 ** be given much smaller limits designed to prevent a denial of service 3533 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3534 ** interface to further control untrusted SQL. The size of the database 3535 ** created by an untrusted script can be contained using the 3536 ** [max_page_count] [PRAGMA]. 3537 ** 3538 ** New run-time limit categories may be added in future releases. 3539 */ 3540 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3541 3542 /* 3543 ** CAPI3REF: Run-Time Limit Categories 3544 ** KEYWORDS: {limit category} {*limit categories} 3545 ** 3546 ** These constants define various performance limits 3547 ** that can be lowered at run-time using [sqlite3_limit()]. 3548 ** The synopsis of the meanings of the various limits is shown below. 3549 ** Additional information is available at [limits | Limits in SQLite]. 3550 ** 3551 ** <dl> 3552 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3553 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3554 ** 3555 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3556 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3557 ** 3558 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3559 ** <dd>The maximum number of columns in a table definition or in the 3560 ** result set of a [SELECT] or the maximum number of columns in an index 3561 ** or in an ORDER BY or GROUP BY clause.</dd>)^ 3562 ** 3563 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3564 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3565 ** 3566 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3567 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3568 ** 3569 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3570 ** <dd>The maximum number of instructions in a virtual machine program 3571 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3572 ** the equivalent tries to allocate space for more than this many opcodes 3573 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3574 ** 3575 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3576 ** <dd>The maximum number of arguments on a function.</dd>)^ 3577 ** 3578 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3579 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3580 ** 3581 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3582 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3583 ** <dd>The maximum length of the pattern argument to the [LIKE] or 3584 ** [GLOB] operators.</dd>)^ 3585 ** 3586 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3587 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3588 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3589 ** 3590 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3591 ** <dd>The maximum depth of recursion for triggers.</dd>)^ 3592 ** 3593 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3594 ** <dd>The maximum number of auxiliary worker threads that a single 3595 ** [prepared statement] may start.</dd>)^ 3596 ** </dl> 3597 */ 3598 #define SQLITE_LIMIT_LENGTH 0 3599 #define SQLITE_LIMIT_SQL_LENGTH 1 3600 #define SQLITE_LIMIT_COLUMN 2 3601 #define SQLITE_LIMIT_EXPR_DEPTH 3 3602 #define SQLITE_LIMIT_COMPOUND_SELECT 4 3603 #define SQLITE_LIMIT_VDBE_OP 5 3604 #define SQLITE_LIMIT_FUNCTION_ARG 6 3605 #define SQLITE_LIMIT_ATTACHED 7 3606 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3607 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 3608 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 3609 #define SQLITE_LIMIT_WORKER_THREADS 11 3610 3611 /* 3612 ** CAPI3REF: Prepare Flags 3613 ** 3614 ** These constants define various flags that can be passed into 3615 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3616 ** [sqlite3_prepare16_v3()] interfaces. 3617 ** 3618 ** New flags may be added in future releases of SQLite. 3619 ** 3620 ** <dl> 3621 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3622 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3623 ** that the prepared statement will be retained for a long time and 3624 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3625 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3626 ** be used just once or at most a few times and then destroyed using 3627 ** [sqlite3_finalize()] relatively soon. The current implementation acts 3628 ** on this hint by avoiding the use of [lookaside memory] so as not to 3629 ** deplete the limited store of lookaside memory. Future versions of 3630 ** SQLite may act on this hint differently. 3631 ** 3632 ** [[SQLITE_PREPARE_NORMALIZE]] ^(<dt>SQLITE_PREPARE_NORMALIZE</dt> 3633 ** <dd>The SQLITE_PREPARE_NORMALIZE flag indicates that a normalized 3634 ** representation of the SQL statement should be calculated and then 3635 ** associated with the prepared statement, which can be obtained via 3636 ** the [sqlite3_normalized_sql()] interface.)^ The semantics used to 3637 ** normalize a SQL statement are unspecified and subject to change. 3638 ** At a minimum, literal values will be replaced with suitable 3639 ** placeholders. 3640 ** </dl> 3641 */ 3642 #define SQLITE_PREPARE_PERSISTENT 0x01 3643 #define SQLITE_PREPARE_NORMALIZE 0x02 3644 3645 /* 3646 ** CAPI3REF: Compiling An SQL Statement 3647 ** KEYWORDS: {SQL statement compiler} 3648 ** METHOD: sqlite3 3649 ** CONSTRUCTOR: sqlite3_stmt 3650 ** 3651 ** To execute an SQL statement, it must first be compiled into a byte-code 3652 ** program using one of these routines. Or, in other words, these routines 3653 ** are constructors for the [prepared statement] object. 3654 ** 3655 ** The preferred routine to use is [sqlite3_prepare_v2()]. The 3656 ** [sqlite3_prepare()] interface is legacy and should be avoided. 3657 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3658 ** for special purposes. 3659 ** 3660 ** The use of the UTF-8 interfaces is preferred, as SQLite currently 3661 ** does all parsing using UTF-8. The UTF-16 interfaces are provided 3662 ** as a convenience. The UTF-16 interfaces work by converting the 3663 ** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3664 ** 3665 ** The first argument, "db", is a [database connection] obtained from a 3666 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3667 ** [sqlite3_open16()]. The database connection must not have been closed. 3668 ** 3669 ** The second argument, "zSql", is the statement to be compiled, encoded 3670 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3671 ** and sqlite3_prepare_v3() 3672 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3673 ** and sqlite3_prepare16_v3() use UTF-16. 3674 ** 3675 ** ^If the nByte argument is negative, then zSql is read up to the 3676 ** first zero terminator. ^If nByte is positive, then it is the 3677 ** number of bytes read from zSql. ^If nByte is zero, then no prepared 3678 ** statement is generated. 3679 ** If the caller knows that the supplied string is nul-terminated, then 3680 ** there is a small performance advantage to passing an nByte parameter that 3681 ** is the number of bytes in the input string <i>including</i> 3682 ** the nul-terminator. 3683 ** 3684 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3685 ** past the end of the first SQL statement in zSql. These routines only 3686 ** compile the first statement in zSql, so *pzTail is left pointing to 3687 ** what remains uncompiled. 3688 ** 3689 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3690 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3691 ** to NULL. ^If the input text contains no SQL (if the input is an empty 3692 ** string or a comment) then *ppStmt is set to NULL. 3693 ** The calling procedure is responsible for deleting the compiled 3694 ** SQL statement using [sqlite3_finalize()] after it has finished with it. 3695 ** ppStmt may not be NULL. 3696 ** 3697 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3698 ** otherwise an [error code] is returned. 3699 ** 3700 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3701 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3702 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3703 ** are retained for backwards compatibility, but their use is discouraged. 3704 ** ^In the "vX" interfaces, the prepared statement 3705 ** that is returned (the [sqlite3_stmt] object) contains a copy of the 3706 ** original SQL text. This causes the [sqlite3_step()] interface to 3707 ** behave differently in three ways: 3708 ** 3709 ** <ol> 3710 ** <li> 3711 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3712 ** always used to do, [sqlite3_step()] will automatically recompile the SQL 3713 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3714 ** retries will occur before sqlite3_step() gives up and returns an error. 3715 ** </li> 3716 ** 3717 ** <li> 3718 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3719 ** [error codes] or [extended error codes]. ^The legacy behavior was that 3720 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3721 ** and the application would have to make a second call to [sqlite3_reset()] 3722 ** in order to find the underlying cause of the problem. With the "v2" prepare 3723 ** interfaces, the underlying reason for the error is returned immediately. 3724 ** </li> 3725 ** 3726 ** <li> 3727 ** ^If the specific value bound to [parameter | host parameter] in the 3728 ** WHERE clause might influence the choice of query plan for a statement, 3729 ** then the statement will be automatically recompiled, as if there had been 3730 ** a schema change, on the first [sqlite3_step()] call following any change 3731 ** to the [sqlite3_bind_text | bindings] of that [parameter]. 3732 ** ^The specific value of WHERE-clause [parameter] might influence the 3733 ** choice of query plan if the parameter is the left-hand side of a [LIKE] 3734 ** or [GLOB] operator or if the parameter is compared to an indexed column 3735 ** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3736 ** </li> 3737 ** </ol> 3738 ** 3739 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3740 ** the extra prepFlags parameter, which is a bit array consisting of zero or 3741 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3742 ** sqlite3_prepare_v2() interface works exactly the same as 3743 ** sqlite3_prepare_v3() with a zero prepFlags parameter. 3744 */ 3745 SQLITE_API int sqlite3_prepare( 3746 sqlite3 *db, /* Database handle */ 3747 const char *zSql, /* SQL statement, UTF-8 encoded */ 3748 int nByte, /* Maximum length of zSql in bytes. */ 3749 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3750 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3751 ); 3752 SQLITE_API int sqlite3_prepare_v2( 3753 sqlite3 *db, /* Database handle */ 3754 const char *zSql, /* SQL statement, UTF-8 encoded */ 3755 int nByte, /* Maximum length of zSql in bytes. */ 3756 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3757 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3758 ); 3759 SQLITE_API int sqlite3_prepare_v3( 3760 sqlite3 *db, /* Database handle */ 3761 const char *zSql, /* SQL statement, UTF-8 encoded */ 3762 int nByte, /* Maximum length of zSql in bytes. */ 3763 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3764 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3765 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3766 ); 3767 SQLITE_API int sqlite3_prepare16( 3768 sqlite3 *db, /* Database handle */ 3769 const void *zSql, /* SQL statement, UTF-16 encoded */ 3770 int nByte, /* Maximum length of zSql in bytes. */ 3771 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3772 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3773 ); 3774 SQLITE_API int sqlite3_prepare16_v2( 3775 sqlite3 *db, /* Database handle */ 3776 const void *zSql, /* SQL statement, UTF-16 encoded */ 3777 int nByte, /* Maximum length of zSql in bytes. */ 3778 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3779 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3780 ); 3781 SQLITE_API int sqlite3_prepare16_v3( 3782 sqlite3 *db, /* Database handle */ 3783 const void *zSql, /* SQL statement, UTF-16 encoded */ 3784 int nByte, /* Maximum length of zSql in bytes. */ 3785 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3786 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3787 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3788 ); 3789 3790 /* 3791 ** CAPI3REF: Retrieving Statement SQL 3792 ** METHOD: sqlite3_stmt 3793 ** 3794 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3795 ** SQL text used to create [prepared statement] P if P was 3796 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3797 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3798 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3799 ** string containing the SQL text of prepared statement P with 3800 ** [bound parameters] expanded. 3801 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3802 ** string containing the normalized SQL text of prepared statement P. The 3803 ** semantics used to normalize a SQL statement are unspecified and subject 3804 ** to change. At a minimum, literal values will be replaced with suitable 3805 ** placeholders. 3806 ** 3807 ** ^(For example, if a prepared statement is created using the SQL 3808 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3809 ** and parameter :xyz is unbound, then sqlite3_sql() will return 3810 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3811 ** will return "SELECT 2345,NULL".)^ 3812 ** 3813 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3814 ** is available to hold the result, or if the result would exceed the 3815 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3816 ** 3817 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3818 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3819 ** option causes sqlite3_expanded_sql() to always return NULL. 3820 ** 3821 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3822 ** are managed by SQLite and are automatically freed when the prepared 3823 ** statement is finalized. 3824 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3825 ** is obtained from [sqlite3_malloc()] and must be free by the application 3826 ** by passing it to [sqlite3_free()]. 3827 */ 3828 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3829 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3830 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3831 3832 /* 3833 ** CAPI3REF: Determine If An SQL Statement Writes The Database 3834 ** METHOD: sqlite3_stmt 3835 ** 3836 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3837 ** and only if the [prepared statement] X makes no direct changes to 3838 ** the content of the database file. 3839 ** 3840 ** Note that [application-defined SQL functions] or 3841 ** [virtual tables] might change the database indirectly as a side effect. 3842 ** ^(For example, if an application defines a function "eval()" that 3843 ** calls [sqlite3_exec()], then the following SQL statement would 3844 ** change the database file through side-effects: 3845 ** 3846 ** <blockquote><pre> 3847 ** SELECT eval('DELETE FROM t1') FROM t2; 3848 ** </pre></blockquote> 3849 ** 3850 ** But because the [SELECT] statement does not change the database file 3851 ** directly, sqlite3_stmt_readonly() would still return true.)^ 3852 ** 3853 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3854 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3855 ** since the statements themselves do not actually modify the database but 3856 ** rather they control the timing of when other statements modify the 3857 ** database. ^The [ATTACH] and [DETACH] statements also cause 3858 ** sqlite3_stmt_readonly() to return true since, while those statements 3859 ** change the configuration of a database connection, they do not make 3860 ** changes to the content of the database files on disk. 3861 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3862 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3863 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3864 ** sqlite3_stmt_readonly() returns false for those commands. 3865 */ 3866 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3867 3868 /* 3869 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3870 ** METHOD: sqlite3_stmt 3871 ** 3872 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3873 ** [prepared statement] S has been stepped at least once using 3874 ** [sqlite3_step(S)] but has neither run to completion (returned 3875 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3876 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3877 ** interface returns false if S is a NULL pointer. If S is not a 3878 ** NULL pointer and is not a pointer to a valid [prepared statement] 3879 ** object, then the behavior is undefined and probably undesirable. 3880 ** 3881 ** This interface can be used in combination [sqlite3_next_stmt()] 3882 ** to locate all prepared statements associated with a database 3883 ** connection that are in need of being reset. This can be used, 3884 ** for example, in diagnostic routines to search for prepared 3885 ** statements that are holding a transaction open. 3886 */ 3887 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3888 3889 /* 3890 ** CAPI3REF: Dynamically Typed Value Object 3891 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3892 ** 3893 ** SQLite uses the sqlite3_value object to represent all values 3894 ** that can be stored in a database table. SQLite uses dynamic typing 3895 ** for the values it stores. ^Values stored in sqlite3_value objects 3896 ** can be integers, floating point values, strings, BLOBs, or NULL. 3897 ** 3898 ** An sqlite3_value object may be either "protected" or "unprotected". 3899 ** Some interfaces require a protected sqlite3_value. Other interfaces 3900 ** will accept either a protected or an unprotected sqlite3_value. 3901 ** Every interface that accepts sqlite3_value arguments specifies 3902 ** whether or not it requires a protected sqlite3_value. The 3903 ** [sqlite3_value_dup()] interface can be used to construct a new 3904 ** protected sqlite3_value from an unprotected sqlite3_value. 3905 ** 3906 ** The terms "protected" and "unprotected" refer to whether or not 3907 ** a mutex is held. An internal mutex is held for a protected 3908 ** sqlite3_value object but no mutex is held for an unprotected 3909 ** sqlite3_value object. If SQLite is compiled to be single-threaded 3910 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3911 ** or if SQLite is run in one of reduced mutex modes 3912 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3913 ** then there is no distinction between protected and unprotected 3914 ** sqlite3_value objects and they can be used interchangeably. However, 3915 ** for maximum code portability it is recommended that applications 3916 ** still make the distinction between protected and unprotected 3917 ** sqlite3_value objects even when not strictly required. 3918 ** 3919 ** ^The sqlite3_value objects that are passed as parameters into the 3920 ** implementation of [application-defined SQL functions] are protected. 3921 ** ^The sqlite3_value object returned by 3922 ** [sqlite3_column_value()] is unprotected. 3923 ** Unprotected sqlite3_value objects may only be used as arguments 3924 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3925 ** [sqlite3_value_dup()]. 3926 ** The [sqlite3_value_blob | sqlite3_value_type()] family of 3927 ** interfaces require protected sqlite3_value objects. 3928 */ 3929 typedef struct sqlite3_value sqlite3_value; 3930 3931 /* 3932 ** CAPI3REF: SQL Function Context Object 3933 ** 3934 ** The context in which an SQL function executes is stored in an 3935 ** sqlite3_context object. ^A pointer to an sqlite3_context object 3936 ** is always first parameter to [application-defined SQL functions]. 3937 ** The application-defined SQL function implementation will pass this 3938 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3939 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3940 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3941 ** and/or [sqlite3_set_auxdata()]. 3942 */ 3943 typedef struct sqlite3_context sqlite3_context; 3944 3945 /* 3946 ** CAPI3REF: Binding Values To Prepared Statements 3947 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3948 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3949 ** METHOD: sqlite3_stmt 3950 ** 3951 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3952 ** literals may be replaced by a [parameter] that matches one of following 3953 ** templates: 3954 ** 3955 ** <ul> 3956 ** <li> ? 3957 ** <li> ?NNN 3958 ** <li> :VVV 3959 ** <li> @VVV 3960 ** <li> $VVV 3961 ** </ul> 3962 ** 3963 ** In the templates above, NNN represents an integer literal, 3964 ** and VVV represents an alphanumeric identifier.)^ ^The values of these 3965 ** parameters (also called "host parameter names" or "SQL parameters") 3966 ** can be set using the sqlite3_bind_*() routines defined here. 3967 ** 3968 ** ^The first argument to the sqlite3_bind_*() routines is always 3969 ** a pointer to the [sqlite3_stmt] object returned from 3970 ** [sqlite3_prepare_v2()] or its variants. 3971 ** 3972 ** ^The second argument is the index of the SQL parameter to be set. 3973 ** ^The leftmost SQL parameter has an index of 1. ^When the same named 3974 ** SQL parameter is used more than once, second and subsequent 3975 ** occurrences have the same index as the first occurrence. 3976 ** ^The index for named parameters can be looked up using the 3977 ** [sqlite3_bind_parameter_index()] API if desired. ^The index 3978 ** for "?NNN" parameters is the value of NNN. 3979 ** ^The NNN value must be between 1 and the [sqlite3_limit()] 3980 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3981 ** 3982 ** ^The third argument is the value to bind to the parameter. 3983 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3984 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3985 ** is ignored and the end result is the same as sqlite3_bind_null(). 3986 ** 3987 ** ^(In those routines that have a fourth argument, its value is the 3988 ** number of bytes in the parameter. To be clear: the value is the 3989 ** number of <u>bytes</u> in the value, not the number of characters.)^ 3990 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3991 ** is negative, then the length of the string is 3992 ** the number of bytes up to the first zero terminator. 3993 ** If the fourth parameter to sqlite3_bind_blob() is negative, then 3994 ** the behavior is undefined. 3995 ** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3996 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3997 ** that parameter must be the byte offset 3998 ** where the NUL terminator would occur assuming the string were NUL 3999 ** terminated. If any NUL characters occur at byte offsets less than 4000 ** the value of the fourth parameter then the resulting string value will 4001 ** contain embedded NULs. The result of expressions involving strings 4002 ** with embedded NULs is undefined. 4003 ** 4004 ** ^The fifth argument to the BLOB and string binding interfaces 4005 ** is a destructor used to dispose of the BLOB or 4006 ** string after SQLite has finished with it. ^The destructor is called 4007 ** to dispose of the BLOB or string even if the call to bind API fails. 4008 ** ^If the fifth argument is 4009 ** the special value [SQLITE_STATIC], then SQLite assumes that the 4010 ** information is in static, unmanaged space and does not need to be freed. 4011 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4012 ** SQLite makes its own private copy of the data immediately, before 4013 ** the sqlite3_bind_*() routine returns. 4014 ** 4015 ** ^The sixth argument to sqlite3_bind_text64() must be one of 4016 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4017 ** to specify the encoding of the text in the third parameter. If 4018 ** the sixth argument to sqlite3_bind_text64() is not one of the 4019 ** allowed values shown above, or if the text encoding is different 4020 ** from the encoding specified by the sixth parameter, then the behavior 4021 ** is undefined. 4022 ** 4023 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4024 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4025 ** (just an integer to hold its size) while it is being processed. 4026 ** Zeroblobs are intended to serve as placeholders for BLOBs whose 4027 ** content is later written using 4028 ** [sqlite3_blob_open | incremental BLOB I/O] routines. 4029 ** ^A negative value for the zeroblob results in a zero-length BLOB. 4030 ** 4031 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4032 ** [prepared statement] S to have an SQL value of NULL, but to also be 4033 ** associated with the pointer P of type T. ^D is either a NULL pointer or 4034 ** a pointer to a destructor function for P. ^SQLite will invoke the 4035 ** destructor D with a single argument of P when it is finished using 4036 ** P. The T parameter should be a static string, preferably a string 4037 ** literal. The sqlite3_bind_pointer() routine is part of the 4038 ** [pointer passing interface] added for SQLite 3.20.0. 4039 ** 4040 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4041 ** for the [prepared statement] or with a prepared statement for which 4042 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4043 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4044 ** routine is passed a [prepared statement] that has been finalized, the 4045 ** result is undefined and probably harmful. 4046 ** 4047 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4048 ** ^Unbound parameters are interpreted as NULL. 4049 ** 4050 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4051 ** [error code] if anything goes wrong. 4052 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4053 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4054 ** [SQLITE_MAX_LENGTH]. 4055 ** ^[SQLITE_RANGE] is returned if the parameter 4056 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4057 ** 4058 ** See also: [sqlite3_bind_parameter_count()], 4059 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4060 */ 4061 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4062 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4063 void(*)(void*)); 4064 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4065 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4066 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4067 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4068 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4069 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4070 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4071 void(*)(void*), unsigned char encoding); 4072 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4073 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4074 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4075 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4076 4077 /* 4078 ** CAPI3REF: Number Of SQL Parameters 4079 ** METHOD: sqlite3_stmt 4080 ** 4081 ** ^This routine can be used to find the number of [SQL parameters] 4082 ** in a [prepared statement]. SQL parameters are tokens of the 4083 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4084 ** placeholders for values that are [sqlite3_bind_blob | bound] 4085 ** to the parameters at a later time. 4086 ** 4087 ** ^(This routine actually returns the index of the largest (rightmost) 4088 ** parameter. For all forms except ?NNN, this will correspond to the 4089 ** number of unique parameters. If parameters of the ?NNN form are used, 4090 ** there may be gaps in the list.)^ 4091 ** 4092 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4093 ** [sqlite3_bind_parameter_name()], and 4094 ** [sqlite3_bind_parameter_index()]. 4095 */ 4096 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4097 4098 /* 4099 ** CAPI3REF: Name Of A Host Parameter 4100 ** METHOD: sqlite3_stmt 4101 ** 4102 ** ^The sqlite3_bind_parameter_name(P,N) interface returns 4103 ** the name of the N-th [SQL parameter] in the [prepared statement] P. 4104 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4105 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4106 ** respectively. 4107 ** In other words, the initial ":" or "$" or "@" or "?" 4108 ** is included as part of the name.)^ 4109 ** ^Parameters of the form "?" without a following integer have no name 4110 ** and are referred to as "nameless" or "anonymous parameters". 4111 ** 4112 ** ^The first host parameter has an index of 1, not 0. 4113 ** 4114 ** ^If the value N is out of range or if the N-th parameter is 4115 ** nameless, then NULL is returned. ^The returned string is 4116 ** always in UTF-8 encoding even if the named parameter was 4117 ** originally specified as UTF-16 in [sqlite3_prepare16()], 4118 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4119 ** 4120 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4121 ** [sqlite3_bind_parameter_count()], and 4122 ** [sqlite3_bind_parameter_index()]. 4123 */ 4124 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4125 4126 /* 4127 ** CAPI3REF: Index Of A Parameter With A Given Name 4128 ** METHOD: sqlite3_stmt 4129 ** 4130 ** ^Return the index of an SQL parameter given its name. ^The 4131 ** index value returned is suitable for use as the second 4132 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4133 ** is returned if no matching parameter is found. ^The parameter 4134 ** name must be given in UTF-8 even if the original statement 4135 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4136 ** [sqlite3_prepare16_v3()]. 4137 ** 4138 ** See also: [sqlite3_bind_blob|sqlite3_bind()], 4139 ** [sqlite3_bind_parameter_count()], and 4140 ** [sqlite3_bind_parameter_name()]. 4141 */ 4142 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4143 4144 /* 4145 ** CAPI3REF: Reset All Bindings On A Prepared Statement 4146 ** METHOD: sqlite3_stmt 4147 ** 4148 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4149 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4150 ** ^Use this routine to reset all host parameters to NULL. 4151 */ 4152 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4153 4154 /* 4155 ** CAPI3REF: Number Of Columns In A Result Set 4156 ** METHOD: sqlite3_stmt 4157 ** 4158 ** ^Return the number of columns in the result set returned by the 4159 ** [prepared statement]. ^If this routine returns 0, that means the 4160 ** [prepared statement] returns no data (for example an [UPDATE]). 4161 ** ^However, just because this routine returns a positive number does not 4162 ** mean that one or more rows of data will be returned. ^A SELECT statement 4163 ** will always have a positive sqlite3_column_count() but depending on the 4164 ** WHERE clause constraints and the table content, it might return no rows. 4165 ** 4166 ** See also: [sqlite3_data_count()] 4167 */ 4168 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4169 4170 /* 4171 ** CAPI3REF: Column Names In A Result Set 4172 ** METHOD: sqlite3_stmt 4173 ** 4174 ** ^These routines return the name assigned to a particular column 4175 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4176 ** interface returns a pointer to a zero-terminated UTF-8 string 4177 ** and sqlite3_column_name16() returns a pointer to a zero-terminated 4178 ** UTF-16 string. ^The first parameter is the [prepared statement] 4179 ** that implements the [SELECT] statement. ^The second parameter is the 4180 ** column number. ^The leftmost column is number 0. 4181 ** 4182 ** ^The returned string pointer is valid until either the [prepared statement] 4183 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4184 ** reprepared by the first call to [sqlite3_step()] for a particular run 4185 ** or until the next call to 4186 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4187 ** 4188 ** ^If sqlite3_malloc() fails during the processing of either routine 4189 ** (for example during a conversion from UTF-8 to UTF-16) then a 4190 ** NULL pointer is returned. 4191 ** 4192 ** ^The name of a result column is the value of the "AS" clause for 4193 ** that column, if there is an AS clause. If there is no AS clause 4194 ** then the name of the column is unspecified and may change from 4195 ** one release of SQLite to the next. 4196 */ 4197 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4198 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4199 4200 /* 4201 ** CAPI3REF: Source Of Data In A Query Result 4202 ** METHOD: sqlite3_stmt 4203 ** 4204 ** ^These routines provide a means to determine the database, table, and 4205 ** table column that is the origin of a particular result column in 4206 ** [SELECT] statement. 4207 ** ^The name of the database or table or column can be returned as 4208 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4209 ** the database name, the _table_ routines return the table name, and 4210 ** the origin_ routines return the column name. 4211 ** ^The returned string is valid until the [prepared statement] is destroyed 4212 ** using [sqlite3_finalize()] or until the statement is automatically 4213 ** reprepared by the first call to [sqlite3_step()] for a particular run 4214 ** or until the same information is requested 4215 ** again in a different encoding. 4216 ** 4217 ** ^The names returned are the original un-aliased names of the 4218 ** database, table, and column. 4219 ** 4220 ** ^The first argument to these interfaces is a [prepared statement]. 4221 ** ^These functions return information about the Nth result column returned by 4222 ** the statement, where N is the second function argument. 4223 ** ^The left-most column is column 0 for these routines. 4224 ** 4225 ** ^If the Nth column returned by the statement is an expression or 4226 ** subquery and is not a column value, then all of these functions return 4227 ** NULL. ^These routine might also return NULL if a memory allocation error 4228 ** occurs. ^Otherwise, they return the name of the attached database, table, 4229 ** or column that query result column was extracted from. 4230 ** 4231 ** ^As with all other SQLite APIs, those whose names end with "16" return 4232 ** UTF-16 encoded strings and the other functions return UTF-8. 4233 ** 4234 ** ^These APIs are only available if the library was compiled with the 4235 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4236 ** 4237 ** If two or more threads call one or more of these routines against the same 4238 ** prepared statement and column at the same time then the results are 4239 ** undefined. 4240 ** 4241 ** If two or more threads call one or more 4242 ** [sqlite3_column_database_name | column metadata interfaces] 4243 ** for the same [prepared statement] and result column 4244 ** at the same time then the results are undefined. 4245 */ 4246 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4247 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4248 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4249 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4250 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4251 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4252 4253 /* 4254 ** CAPI3REF: Declared Datatype Of A Query Result 4255 ** METHOD: sqlite3_stmt 4256 ** 4257 ** ^(The first parameter is a [prepared statement]. 4258 ** If this statement is a [SELECT] statement and the Nth column of the 4259 ** returned result set of that [SELECT] is a table column (not an 4260 ** expression or subquery) then the declared type of the table 4261 ** column is returned.)^ ^If the Nth column of the result set is an 4262 ** expression or subquery, then a NULL pointer is returned. 4263 ** ^The returned string is always UTF-8 encoded. 4264 ** 4265 ** ^(For example, given the database schema: 4266 ** 4267 ** CREATE TABLE t1(c1 VARIANT); 4268 ** 4269 ** and the following statement to be compiled: 4270 ** 4271 ** SELECT c1 + 1, c1 FROM t1; 4272 ** 4273 ** this routine would return the string "VARIANT" for the second result 4274 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4275 ** 4276 ** ^SQLite uses dynamic run-time typing. ^So just because a column 4277 ** is declared to contain a particular type does not mean that the 4278 ** data stored in that column is of the declared type. SQLite is 4279 ** strongly typed, but the typing is dynamic not static. ^Type 4280 ** is associated with individual values, not with the containers 4281 ** used to hold those values. 4282 */ 4283 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4284 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4285 4286 /* 4287 ** CAPI3REF: Evaluate An SQL Statement 4288 ** METHOD: sqlite3_stmt 4289 ** 4290 ** After a [prepared statement] has been prepared using any of 4291 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4292 ** or [sqlite3_prepare16_v3()] or one of the legacy 4293 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4294 ** must be called one or more times to evaluate the statement. 4295 ** 4296 ** The details of the behavior of the sqlite3_step() interface depend 4297 ** on whether the statement was prepared using the newer "vX" interfaces 4298 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4299 ** [sqlite3_prepare16_v2()] or the older legacy 4300 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4301 ** new "vX" interface is recommended for new applications but the legacy 4302 ** interface will continue to be supported. 4303 ** 4304 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4305 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4306 ** ^With the "v2" interface, any of the other [result codes] or 4307 ** [extended result codes] might be returned as well. 4308 ** 4309 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4310 ** database locks it needs to do its job. ^If the statement is a [COMMIT] 4311 ** or occurs outside of an explicit transaction, then you can retry the 4312 ** statement. If the statement is not a [COMMIT] and occurs within an 4313 ** explicit transaction then you should rollback the transaction before 4314 ** continuing. 4315 ** 4316 ** ^[SQLITE_DONE] means that the statement has finished executing 4317 ** successfully. sqlite3_step() should not be called again on this virtual 4318 ** machine without first calling [sqlite3_reset()] to reset the virtual 4319 ** machine back to its initial state. 4320 ** 4321 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4322 ** is returned each time a new row of data is ready for processing by the 4323 ** caller. The values may be accessed using the [column access functions]. 4324 ** sqlite3_step() is called again to retrieve the next row of data. 4325 ** 4326 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4327 ** violation) has occurred. sqlite3_step() should not be called again on 4328 ** the VM. More information may be found by calling [sqlite3_errmsg()]. 4329 ** ^With the legacy interface, a more specific error code (for example, 4330 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4331 ** can be obtained by calling [sqlite3_reset()] on the 4332 ** [prepared statement]. ^In the "v2" interface, 4333 ** the more specific error code is returned directly by sqlite3_step(). 4334 ** 4335 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4336 ** Perhaps it was called on a [prepared statement] that has 4337 ** already been [sqlite3_finalize | finalized] or on one that had 4338 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4339 ** be the case that the same database connection is being used by two or 4340 ** more threads at the same moment in time. 4341 ** 4342 ** For all versions of SQLite up to and including 3.6.23.1, a call to 4343 ** [sqlite3_reset()] was required after sqlite3_step() returned anything 4344 ** other than [SQLITE_ROW] before any subsequent invocation of 4345 ** sqlite3_step(). Failure to reset the prepared statement using 4346 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4347 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4348 ** sqlite3_step() began 4349 ** calling [sqlite3_reset()] automatically in this circumstance rather 4350 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4351 ** break because any application that ever receives an SQLITE_MISUSE error 4352 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4353 ** can be used to restore the legacy behavior. 4354 ** 4355 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4356 ** API always returns a generic error code, [SQLITE_ERROR], following any 4357 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4358 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4359 ** specific [error codes] that better describes the error. 4360 ** We admit that this is a goofy design. The problem has been fixed 4361 ** with the "v2" interface. If you prepare all of your SQL statements 4362 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4363 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4364 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4365 ** then the more specific [error codes] are returned directly 4366 ** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4367 */ 4368 SQLITE_API int sqlite3_step(sqlite3_stmt*); 4369 4370 /* 4371 ** CAPI3REF: Number of columns in a result set 4372 ** METHOD: sqlite3_stmt 4373 ** 4374 ** ^The sqlite3_data_count(P) interface returns the number of columns in the 4375 ** current row of the result set of [prepared statement] P. 4376 ** ^If prepared statement P does not have results ready to return 4377 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4378 ** interfaces) then sqlite3_data_count(P) returns 0. 4379 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4380 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4381 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4382 ** will return non-zero if previous call to [sqlite3_step](P) returned 4383 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4384 ** where it always returns zero since each step of that multi-step 4385 ** pragma returns 0 columns of data. 4386 ** 4387 ** See also: [sqlite3_column_count()] 4388 */ 4389 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4390 4391 /* 4392 ** CAPI3REF: Fundamental Datatypes 4393 ** KEYWORDS: SQLITE_TEXT 4394 ** 4395 ** ^(Every value in SQLite has one of five fundamental datatypes: 4396 ** 4397 ** <ul> 4398 ** <li> 64-bit signed integer 4399 ** <li> 64-bit IEEE floating point number 4400 ** <li> string 4401 ** <li> BLOB 4402 ** <li> NULL 4403 ** </ul>)^ 4404 ** 4405 ** These constants are codes for each of those types. 4406 ** 4407 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4408 ** for a completely different meaning. Software that links against both 4409 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4410 ** SQLITE_TEXT. 4411 */ 4412 #define SQLITE_INTEGER 1 4413 #define SQLITE_FLOAT 2 4414 #define SQLITE_BLOB 4 4415 #define SQLITE_NULL 5 4416 #ifdef SQLITE_TEXT 4417 # undef SQLITE_TEXT 4418 #else 4419 # define SQLITE_TEXT 3 4420 #endif 4421 #define SQLITE3_TEXT 3 4422 4423 /* 4424 ** CAPI3REF: Result Values From A Query 4425 ** KEYWORDS: {column access functions} 4426 ** METHOD: sqlite3_stmt 4427 ** 4428 ** <b>Summary:</b> 4429 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4430 ** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4431 ** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4432 ** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4433 ** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4434 ** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4435 ** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4436 ** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4437 ** [sqlite3_value|unprotected sqlite3_value] object. 4438 ** <tr><td> <td> <td> 4439 ** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4440 ** or a UTF-8 TEXT result in bytes 4441 ** <tr><td><b>sqlite3_column_bytes16 </b> 4442 ** <td>→ <td>Size of UTF-16 4443 ** TEXT in bytes 4444 ** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4445 ** datatype of the result 4446 ** </table></blockquote> 4447 ** 4448 ** <b>Details:</b> 4449 ** 4450 ** ^These routines return information about a single column of the current 4451 ** result row of a query. ^In every case the first argument is a pointer 4452 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4453 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4454 ** and the second argument is the index of the column for which information 4455 ** should be returned. ^The leftmost column of the result set has the index 0. 4456 ** ^The number of columns in the result can be determined using 4457 ** [sqlite3_column_count()]. 4458 ** 4459 ** If the SQL statement does not currently point to a valid row, or if the 4460 ** column index is out of range, the result is undefined. 4461 ** These routines may only be called when the most recent call to 4462 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4463 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4464 ** If any of these routines are called after [sqlite3_reset()] or 4465 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4466 ** something other than [SQLITE_ROW], the results are undefined. 4467 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4468 ** are called from a different thread while any of these routines 4469 ** are pending, then the results are undefined. 4470 ** 4471 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4472 ** each return the value of a result column in a specific data format. If 4473 ** the result column is not initially in the requested format (for example, 4474 ** if the query returns an integer but the sqlite3_column_text() interface 4475 ** is used to extract the value) then an automatic type conversion is performed. 4476 ** 4477 ** ^The sqlite3_column_type() routine returns the 4478 ** [SQLITE_INTEGER | datatype code] for the initial data type 4479 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4480 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4481 ** The return value of sqlite3_column_type() can be used to decide which 4482 ** of the first six interface should be used to extract the column value. 4483 ** The value returned by sqlite3_column_type() is only meaningful if no 4484 ** automatic type conversions have occurred for the value in question. 4485 ** After a type conversion, the result of calling sqlite3_column_type() 4486 ** is undefined, though harmless. Future 4487 ** versions of SQLite may change the behavior of sqlite3_column_type() 4488 ** following a type conversion. 4489 ** 4490 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4491 ** or sqlite3_column_bytes16() interfaces can be used to determine the size 4492 ** of that BLOB or string. 4493 ** 4494 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4495 ** routine returns the number of bytes in that BLOB or string. 4496 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4497 ** the string to UTF-8 and then returns the number of bytes. 4498 ** ^If the result is a numeric value then sqlite3_column_bytes() uses 4499 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4500 ** the number of bytes in that string. 4501 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4502 ** 4503 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4504 ** routine returns the number of bytes in that BLOB or string. 4505 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4506 ** the string to UTF-16 and then returns the number of bytes. 4507 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4508 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4509 ** the number of bytes in that string. 4510 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4511 ** 4512 ** ^The values returned by [sqlite3_column_bytes()] and 4513 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4514 ** of the string. ^For clarity: the values returned by 4515 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4516 ** bytes in the string, not the number of characters. 4517 ** 4518 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4519 ** even empty strings, are always zero-terminated. ^The return 4520 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4521 ** 4522 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4523 ** [unprotected sqlite3_value] object. In a multithreaded environment, 4524 ** an unprotected sqlite3_value object may only be used safely with 4525 ** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4526 ** If the [unprotected sqlite3_value] object returned by 4527 ** [sqlite3_column_value()] is used in any other way, including calls 4528 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4529 ** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4530 ** Hence, the sqlite3_column_value() interface 4531 ** is normally only useful within the implementation of 4532 ** [application-defined SQL functions] or [virtual tables], not within 4533 ** top-level application code. 4534 ** 4535 ** The these routines may attempt to convert the datatype of the result. 4536 ** ^For example, if the internal representation is FLOAT and a text result 4537 ** is requested, [sqlite3_snprintf()] is used internally to perform the 4538 ** conversion automatically. ^(The following table details the conversions 4539 ** that are applied: 4540 ** 4541 ** <blockquote> 4542 ** <table border="1"> 4543 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4544 ** 4545 ** <tr><td> NULL <td> INTEGER <td> Result is 0 4546 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4547 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4548 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4549 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4550 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4551 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4552 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4553 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4554 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4555 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4556 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4557 ** <tr><td> TEXT <td> BLOB <td> No change 4558 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4559 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4560 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4561 ** </table> 4562 ** </blockquote>)^ 4563 ** 4564 ** Note that when type conversions occur, pointers returned by prior 4565 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4566 ** sqlite3_column_text16() may be invalidated. 4567 ** Type conversions and pointer invalidations might occur 4568 ** in the following cases: 4569 ** 4570 ** <ul> 4571 ** <li> The initial content is a BLOB and sqlite3_column_text() or 4572 ** sqlite3_column_text16() is called. A zero-terminator might 4573 ** need to be added to the string.</li> 4574 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4575 ** sqlite3_column_text16() is called. The content must be converted 4576 ** to UTF-16.</li> 4577 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4578 ** sqlite3_column_text() is called. The content must be converted 4579 ** to UTF-8.</li> 4580 ** </ul> 4581 ** 4582 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4583 ** not invalidate a prior pointer, though of course the content of the buffer 4584 ** that the prior pointer references will have been modified. Other kinds 4585 ** of conversion are done in place when it is possible, but sometimes they 4586 ** are not possible and in those cases prior pointers are invalidated. 4587 ** 4588 ** The safest policy is to invoke these routines 4589 ** in one of the following ways: 4590 ** 4591 ** <ul> 4592 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4593 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4594 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4595 ** </ul> 4596 ** 4597 ** In other words, you should call sqlite3_column_text(), 4598 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4599 ** into the desired format, then invoke sqlite3_column_bytes() or 4600 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4601 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4602 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4603 ** with calls to sqlite3_column_bytes(). 4604 ** 4605 ** ^The pointers returned are valid until a type conversion occurs as 4606 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4607 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4608 ** and BLOBs is freed automatically. Do not pass the pointers returned 4609 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4610 ** [sqlite3_free()]. 4611 ** 4612 ** As long as the input parameters are correct, these routines will only 4613 ** fail if an out-of-memory error occurs during a format conversion. 4614 ** Only the following subset of interfaces are subject to out-of-memory 4615 ** errors: 4616 ** 4617 ** <ul> 4618 ** <li> sqlite3_column_blob() 4619 ** <li> sqlite3_column_text() 4620 ** <li> sqlite3_column_text16() 4621 ** <li> sqlite3_column_bytes() 4622 ** <li> sqlite3_column_bytes16() 4623 ** </ul> 4624 ** 4625 ** If an out-of-memory error occurs, then the return value from these 4626 ** routines is the same as if the column had contained an SQL NULL value. 4627 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 4628 ** by invoking the [sqlite3_errcode()] immediately after the suspect 4629 ** return value is obtained and before any 4630 ** other SQLite interface is called on the same [database connection]. 4631 */ 4632 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4633 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4634 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4635 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4636 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4637 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4638 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4639 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4640 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4641 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4642 4643 /* 4644 ** CAPI3REF: Destroy A Prepared Statement Object 4645 ** DESTRUCTOR: sqlite3_stmt 4646 ** 4647 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4648 ** ^If the most recent evaluation of the statement encountered no errors 4649 ** or if the statement is never been evaluated, then sqlite3_finalize() returns 4650 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4651 ** sqlite3_finalize(S) returns the appropriate [error code] or 4652 ** [extended error code]. 4653 ** 4654 ** ^The sqlite3_finalize(S) routine can be called at any point during 4655 ** the life cycle of [prepared statement] S: 4656 ** before statement S is ever evaluated, after 4657 ** one or more calls to [sqlite3_reset()], or after any call 4658 ** to [sqlite3_step()] regardless of whether or not the statement has 4659 ** completed execution. 4660 ** 4661 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4662 ** 4663 ** The application must finalize every [prepared statement] in order to avoid 4664 ** resource leaks. It is a grievous error for the application to try to use 4665 ** a prepared statement after it has been finalized. Any use of a prepared 4666 ** statement after it has been finalized can result in undefined and 4667 ** undesirable behavior such as segfaults and heap corruption. 4668 */ 4669 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4670 4671 /* 4672 ** CAPI3REF: Reset A Prepared Statement Object 4673 ** METHOD: sqlite3_stmt 4674 ** 4675 ** The sqlite3_reset() function is called to reset a [prepared statement] 4676 ** object back to its initial state, ready to be re-executed. 4677 ** ^Any SQL statement variables that had values bound to them using 4678 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4679 ** Use [sqlite3_clear_bindings()] to reset the bindings. 4680 ** 4681 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4682 ** back to the beginning of its program. 4683 ** 4684 ** ^If the most recent call to [sqlite3_step(S)] for the 4685 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4686 ** or if [sqlite3_step(S)] has never before been called on S, 4687 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4688 ** 4689 ** ^If the most recent call to [sqlite3_step(S)] for the 4690 ** [prepared statement] S indicated an error, then 4691 ** [sqlite3_reset(S)] returns an appropriate [error code]. 4692 ** 4693 ** ^The [sqlite3_reset(S)] interface does not change the values 4694 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4695 */ 4696 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4697 4698 /* 4699 ** CAPI3REF: Create Or Redefine SQL Functions 4700 ** KEYWORDS: {function creation routines} 4701 ** KEYWORDS: {application-defined SQL function} 4702 ** KEYWORDS: {application-defined SQL functions} 4703 ** METHOD: sqlite3 4704 ** 4705 ** ^These functions (collectively known as "function creation routines") 4706 ** are used to add SQL functions or aggregates or to redefine the behavior 4707 ** of existing SQL functions or aggregates. The only differences between 4708 ** the three "sqlite3_create_function*" routines are the text encoding 4709 ** expected for the second parameter (the name of the function being 4710 ** created) and the presence or absence of a destructor callback for 4711 ** the application data pointer. Function sqlite3_create_window_function() 4712 ** is similar, but allows the user to supply the extra callback functions 4713 ** needed by [aggregate window functions]. 4714 ** 4715 ** ^The first parameter is the [database connection] to which the SQL 4716 ** function is to be added. ^If an application uses more than one database 4717 ** connection then application-defined SQL functions must be added 4718 ** to each database connection separately. 4719 ** 4720 ** ^The second parameter is the name of the SQL function to be created or 4721 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4722 ** representation, exclusive of the zero-terminator. ^Note that the name 4723 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4724 ** ^Any attempt to create a function with a longer name 4725 ** will result in [SQLITE_MISUSE] being returned. 4726 ** 4727 ** ^The third parameter (nArg) 4728 ** is the number of arguments that the SQL function or 4729 ** aggregate takes. ^If this parameter is -1, then the SQL function or 4730 ** aggregate may take any number of arguments between 0 and the limit 4731 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4732 ** parameter is less than -1 or greater than 127 then the behavior is 4733 ** undefined. 4734 ** 4735 ** ^The fourth parameter, eTextRep, specifies what 4736 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4737 ** its parameters. The application should set this parameter to 4738 ** [SQLITE_UTF16LE] if the function implementation invokes 4739 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4740 ** implementation invokes [sqlite3_value_text16be()] on an input, or 4741 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4742 ** otherwise. ^The same SQL function may be registered multiple times using 4743 ** different preferred text encodings, with different implementations for 4744 ** each encoding. 4745 ** ^When multiple implementations of the same function are available, SQLite 4746 ** will pick the one that involves the least amount of data conversion. 4747 ** 4748 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4749 ** to signal that the function will always return the same result given 4750 ** the same inputs within a single SQL statement. Most SQL functions are 4751 ** deterministic. The built-in [random()] SQL function is an example of a 4752 ** function that is not deterministic. The SQLite query planner is able to 4753 ** perform additional optimizations on deterministic functions, so use 4754 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4755 ** 4756 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4757 ** function can gain access to this pointer using [sqlite3_user_data()].)^ 4758 ** 4759 ** ^The sixth, seventh and eighth parameters passed to the three 4760 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4761 ** pointers to C-language functions that implement the SQL function or 4762 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4763 ** callback only; NULL pointers must be passed as the xStep and xFinal 4764 ** parameters. ^An aggregate SQL function requires an implementation of xStep 4765 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4766 ** SQL function or aggregate, pass NULL pointers for all three function 4767 ** callbacks. 4768 ** 4769 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4770 ** and xInverse) passed to sqlite3_create_window_function are pointers to 4771 ** C-language callbacks that implement the new function. xStep and xFinal 4772 ** must both be non-NULL. xValue and xInverse may either both be NULL, in 4773 ** which case a regular aggregate function is created, or must both be 4774 ** non-NULL, in which case the new function may be used as either an aggregate 4775 ** or aggregate window function. More details regarding the implementation 4776 ** of aggregate window functions are 4777 ** [user-defined window functions|available here]. 4778 ** 4779 ** ^(If the final parameter to sqlite3_create_function_v2() or 4780 ** sqlite3_create_window_function() is not NULL, then it is destructor for 4781 ** the application data pointer. The destructor is invoked when the function 4782 ** is deleted, either by being overloaded or when the database connection 4783 ** closes.)^ ^The destructor is also invoked if the call to 4784 ** sqlite3_create_function_v2() fails. ^When the destructor callback is 4785 ** invoked, it is passed a single argument which is a copy of the application 4786 ** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4787 ** 4788 ** ^It is permitted to register multiple implementations of the same 4789 ** functions with the same name but with either differing numbers of 4790 ** arguments or differing preferred text encodings. ^SQLite will use 4791 ** the implementation that most closely matches the way in which the 4792 ** SQL function is used. ^A function implementation with a non-negative 4793 ** nArg parameter is a better match than a function implementation with 4794 ** a negative nArg. ^A function where the preferred text encoding 4795 ** matches the database encoding is a better 4796 ** match than a function where the encoding is different. 4797 ** ^A function where the encoding difference is between UTF16le and UTF16be 4798 ** is a closer match than a function where the encoding difference is 4799 ** between UTF8 and UTF16. 4800 ** 4801 ** ^Built-in functions may be overloaded by new application-defined functions. 4802 ** 4803 ** ^An application-defined function is permitted to call other 4804 ** SQLite interfaces. However, such calls must not 4805 ** close the database connection nor finalize or reset the prepared 4806 ** statement in which the function is running. 4807 */ 4808 SQLITE_API int sqlite3_create_function( 4809 sqlite3 *db, 4810 const char *zFunctionName, 4811 int nArg, 4812 int eTextRep, 4813 void *pApp, 4814 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4815 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4816 void (*xFinal)(sqlite3_context*) 4817 ); 4818 SQLITE_API int sqlite3_create_function16( 4819 sqlite3 *db, 4820 const void *zFunctionName, 4821 int nArg, 4822 int eTextRep, 4823 void *pApp, 4824 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4825 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4826 void (*xFinal)(sqlite3_context*) 4827 ); 4828 SQLITE_API int sqlite3_create_function_v2( 4829 sqlite3 *db, 4830 const char *zFunctionName, 4831 int nArg, 4832 int eTextRep, 4833 void *pApp, 4834 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4835 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4836 void (*xFinal)(sqlite3_context*), 4837 void(*xDestroy)(void*) 4838 ); 4839 SQLITE_API int sqlite3_create_window_function( 4840 sqlite3 *db, 4841 const char *zFunctionName, 4842 int nArg, 4843 int eTextRep, 4844 void *pApp, 4845 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4846 void (*xFinal)(sqlite3_context*), 4847 void (*xValue)(sqlite3_context*), 4848 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4849 void(*xDestroy)(void*) 4850 ); 4851 4852 /* 4853 ** CAPI3REF: Text Encodings 4854 ** 4855 ** These constant define integer codes that represent the various 4856 ** text encodings supported by SQLite. 4857 */ 4858 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4859 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4860 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4861 #define SQLITE_UTF16 4 /* Use native byte order */ 4862 #define SQLITE_ANY 5 /* Deprecated */ 4863 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4864 4865 /* 4866 ** CAPI3REF: Function Flags 4867 ** 4868 ** These constants may be ORed together with the 4869 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4870 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4871 ** [sqlite3_create_function_v2()]. 4872 */ 4873 #define SQLITE_DETERMINISTIC 0x800 4874 4875 /* 4876 ** CAPI3REF: Deprecated Functions 4877 ** DEPRECATED 4878 ** 4879 ** These functions are [deprecated]. In order to maintain 4880 ** backwards compatibility with older code, these functions continue 4881 ** to be supported. However, new applications should avoid 4882 ** the use of these functions. To encourage programmers to avoid 4883 ** these functions, we will not explain what they do. 4884 */ 4885 #ifndef SQLITE_OMIT_DEPRECATED 4886 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4887 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4888 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4889 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4890 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4891 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4892 void*,sqlite3_int64); 4893 #endif 4894 4895 /* 4896 ** CAPI3REF: Obtaining SQL Values 4897 ** METHOD: sqlite3_value 4898 ** 4899 ** <b>Summary:</b> 4900 ** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4901 ** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4902 ** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4903 ** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4904 ** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4905 ** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4906 ** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4907 ** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4908 ** the native byteorder 4909 ** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4910 ** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4911 ** <tr><td> <td> <td> 4912 ** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4913 ** or a UTF-8 TEXT in bytes 4914 ** <tr><td><b>sqlite3_value_bytes16 </b> 4915 ** <td>→ <td>Size of UTF-16 4916 ** TEXT in bytes 4917 ** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4918 ** datatype of the value 4919 ** <tr><td><b>sqlite3_value_numeric_type </b> 4920 ** <td>→ <td>Best numeric datatype of the value 4921 ** <tr><td><b>sqlite3_value_nochange </b> 4922 ** <td>→ <td>True if the column is unchanged in an UPDATE 4923 ** against a virtual table. 4924 ** </table></blockquote> 4925 ** 4926 ** <b>Details:</b> 4927 ** 4928 ** These routines extract type, size, and content information from 4929 ** [protected sqlite3_value] objects. Protected sqlite3_value objects 4930 ** are used to pass parameter information into implementation of 4931 ** [application-defined SQL functions] and [virtual tables]. 4932 ** 4933 ** These routines work only with [protected sqlite3_value] objects. 4934 ** Any attempt to use these routines on an [unprotected sqlite3_value] 4935 ** is not threadsafe. 4936 ** 4937 ** ^These routines work just like the corresponding [column access functions] 4938 ** except that these routines take a single [protected sqlite3_value] object 4939 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4940 ** 4941 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4942 ** in the native byte-order of the host machine. ^The 4943 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4944 ** extract UTF-16 strings as big-endian and little-endian respectively. 4945 ** 4946 ** ^If [sqlite3_value] object V was initialized 4947 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4948 ** and if X and Y are strings that compare equal according to strcmp(X,Y), 4949 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4950 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4951 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4952 ** 4953 ** ^(The sqlite3_value_type(V) interface returns the 4954 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4955 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4956 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4957 ** Other interfaces might change the datatype for an sqlite3_value object. 4958 ** For example, if the datatype is initially SQLITE_INTEGER and 4959 ** sqlite3_value_text(V) is called to extract a text value for that 4960 ** integer, then subsequent calls to sqlite3_value_type(V) might return 4961 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4962 ** occurs is undefined and may change from one release of SQLite to the next. 4963 ** 4964 ** ^(The sqlite3_value_numeric_type() interface attempts to apply 4965 ** numeric affinity to the value. This means that an attempt is 4966 ** made to convert the value to an integer or floating point. If 4967 ** such a conversion is possible without loss of information (in other 4968 ** words, if the value is a string that looks like a number) 4969 ** then the conversion is performed. Otherwise no conversion occurs. 4970 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4971 ** 4972 ** ^Within the [xUpdate] method of a [virtual table], the 4973 ** sqlite3_value_nochange(X) interface returns true if and only if 4974 ** the column corresponding to X is unchanged by the UPDATE operation 4975 ** that the xUpdate method call was invoked to implement and if 4976 ** and the prior [xColumn] method call that was invoked to extracted 4977 ** the value for that column returned without setting a result (probably 4978 ** because it queried [sqlite3_vtab_nochange()] and found that the column 4979 ** was unchanging). ^Within an [xUpdate] method, any value for which 4980 ** sqlite3_value_nochange(X) is true will in all other respects appear 4981 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4982 ** than within an [xUpdate] method call for an UPDATE statement, then 4983 ** the return value is arbitrary and meaningless. 4984 ** 4985 ** Please pay particular attention to the fact that the pointer returned 4986 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4987 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4988 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4989 ** or [sqlite3_value_text16()]. 4990 ** 4991 ** These routines must be called from the same thread as 4992 ** the SQL function that supplied the [sqlite3_value*] parameters. 4993 ** 4994 ** As long as the input parameter is correct, these routines can only 4995 ** fail if an out-of-memory error occurs during a format conversion. 4996 ** Only the following subset of interfaces are subject to out-of-memory 4997 ** errors: 4998 ** 4999 ** <ul> 5000 ** <li> sqlite3_value_blob() 5001 ** <li> sqlite3_value_text() 5002 ** <li> sqlite3_value_text16() 5003 ** <li> sqlite3_value_text16le() 5004 ** <li> sqlite3_value_text16be() 5005 ** <li> sqlite3_value_bytes() 5006 ** <li> sqlite3_value_bytes16() 5007 ** </ul> 5008 ** 5009 ** If an out-of-memory error occurs, then the return value from these 5010 ** routines is the same as if the column had contained an SQL NULL value. 5011 ** Valid SQL NULL returns can be distinguished from out-of-memory errors 5012 ** by invoking the [sqlite3_errcode()] immediately after the suspect 5013 ** return value is obtained and before any 5014 ** other SQLite interface is called on the same [database connection]. 5015 */ 5016 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5017 SQLITE_API double sqlite3_value_double(sqlite3_value*); 5018 SQLITE_API int sqlite3_value_int(sqlite3_value*); 5019 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5020 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5021 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5022 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5023 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5024 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5025 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5026 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5027 SQLITE_API int sqlite3_value_type(sqlite3_value*); 5028 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5029 SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5030 5031 /* 5032 ** CAPI3REF: Finding The Subtype Of SQL Values 5033 ** METHOD: sqlite3_value 5034 ** 5035 ** The sqlite3_value_subtype(V) function returns the subtype for 5036 ** an [application-defined SQL function] argument V. The subtype 5037 ** information can be used to pass a limited amount of context from 5038 ** one SQL function to another. Use the [sqlite3_result_subtype()] 5039 ** routine to set the subtype for the return value of an SQL function. 5040 */ 5041 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5042 5043 /* 5044 ** CAPI3REF: Copy And Free SQL Values 5045 ** METHOD: sqlite3_value 5046 ** 5047 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5048 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5049 ** is a [protected sqlite3_value] object even if the input is not. 5050 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5051 ** memory allocation fails. 5052 ** 5053 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5054 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5055 ** then sqlite3_value_free(V) is a harmless no-op. 5056 */ 5057 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5058 SQLITE_API void sqlite3_value_free(sqlite3_value*); 5059 5060 /* 5061 ** CAPI3REF: Obtain Aggregate Function Context 5062 ** METHOD: sqlite3_context 5063 ** 5064 ** Implementations of aggregate SQL functions use this 5065 ** routine to allocate memory for storing their state. 5066 ** 5067 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5068 ** for a particular aggregate function, SQLite 5069 ** allocates N of memory, zeroes out that memory, and returns a pointer 5070 ** to the new memory. ^On second and subsequent calls to 5071 ** sqlite3_aggregate_context() for the same aggregate function instance, 5072 ** the same buffer is returned. Sqlite3_aggregate_context() is normally 5073 ** called once for each invocation of the xStep callback and then one 5074 ** last time when the xFinal callback is invoked. ^(When no rows match 5075 ** an aggregate query, the xStep() callback of the aggregate function 5076 ** implementation is never called and xFinal() is called exactly once. 5077 ** In those cases, sqlite3_aggregate_context() might be called for the 5078 ** first time from within xFinal().)^ 5079 ** 5080 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5081 ** when first called if N is less than or equal to zero or if a memory 5082 ** allocate error occurs. 5083 ** 5084 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5085 ** determined by the N parameter on first successful call. Changing the 5086 ** value of N in subsequent call to sqlite3_aggregate_context() within 5087 ** the same aggregate function instance will not resize the memory 5088 ** allocation.)^ Within the xFinal callback, it is customary to set 5089 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5090 ** pointless memory allocations occur. 5091 ** 5092 ** ^SQLite automatically frees the memory allocated by 5093 ** sqlite3_aggregate_context() when the aggregate query concludes. 5094 ** 5095 ** The first parameter must be a copy of the 5096 ** [sqlite3_context | SQL function context] that is the first parameter 5097 ** to the xStep or xFinal callback routine that implements the aggregate 5098 ** function. 5099 ** 5100 ** This routine must be called from the same thread in which 5101 ** the aggregate SQL function is running. 5102 */ 5103 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5104 5105 /* 5106 ** CAPI3REF: User Data For Functions 5107 ** METHOD: sqlite3_context 5108 ** 5109 ** ^The sqlite3_user_data() interface returns a copy of 5110 ** the pointer that was the pUserData parameter (the 5th parameter) 5111 ** of the [sqlite3_create_function()] 5112 ** and [sqlite3_create_function16()] routines that originally 5113 ** registered the application defined function. 5114 ** 5115 ** This routine must be called from the same thread in which 5116 ** the application-defined function is running. 5117 */ 5118 SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5119 5120 /* 5121 ** CAPI3REF: Database Connection For Functions 5122 ** METHOD: sqlite3_context 5123 ** 5124 ** ^The sqlite3_context_db_handle() interface returns a copy of 5125 ** the pointer to the [database connection] (the 1st parameter) 5126 ** of the [sqlite3_create_function()] 5127 ** and [sqlite3_create_function16()] routines that originally 5128 ** registered the application defined function. 5129 */ 5130 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5131 5132 /* 5133 ** CAPI3REF: Function Auxiliary Data 5134 ** METHOD: sqlite3_context 5135 ** 5136 ** These functions may be used by (non-aggregate) SQL functions to 5137 ** associate metadata with argument values. If the same value is passed to 5138 ** multiple invocations of the same SQL function during query execution, under 5139 ** some circumstances the associated metadata may be preserved. An example 5140 ** of where this might be useful is in a regular-expression matching 5141 ** function. The compiled version of the regular expression can be stored as 5142 ** metadata associated with the pattern string. 5143 ** Then as long as the pattern string remains the same, 5144 ** the compiled regular expression can be reused on multiple 5145 ** invocations of the same function. 5146 ** 5147 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5148 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5149 ** value to the application-defined function. ^N is zero for the left-most 5150 ** function argument. ^If there is no metadata 5151 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5152 ** returns a NULL pointer. 5153 ** 5154 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5155 ** argument of the application-defined function. ^Subsequent 5156 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5157 ** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5158 ** NULL if the metadata has been discarded. 5159 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5160 ** SQLite will invoke the destructor function X with parameter P exactly 5161 ** once, when the metadata is discarded. 5162 ** SQLite is free to discard the metadata at any time, including: <ul> 5163 ** <li> ^(when the corresponding function parameter changes)^, or 5164 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5165 ** SQL statement)^, or 5166 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5167 ** parameter)^, or 5168 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5169 ** allocation error occurs.)^ </ul> 5170 ** 5171 ** Note the last bullet in particular. The destructor X in 5172 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5173 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5174 ** should be called near the end of the function implementation and the 5175 ** function implementation should not make any use of P after 5176 ** sqlite3_set_auxdata() has been called. 5177 ** 5178 ** ^(In practice, metadata is preserved between function calls for 5179 ** function parameters that are compile-time constants, including literal 5180 ** values and [parameters] and expressions composed from the same.)^ 5181 ** 5182 ** The value of the N parameter to these interfaces should be non-negative. 5183 ** Future enhancements may make use of negative N values to define new 5184 ** kinds of function caching behavior. 5185 ** 5186 ** These routines must be called from the same thread in which 5187 ** the SQL function is running. 5188 */ 5189 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5190 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5191 5192 5193 /* 5194 ** CAPI3REF: Constants Defining Special Destructor Behavior 5195 ** 5196 ** These are special values for the destructor that is passed in as the 5197 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5198 ** argument is SQLITE_STATIC, it means that the content pointer is constant 5199 ** and will never change. It does not need to be destroyed. ^The 5200 ** SQLITE_TRANSIENT value means that the content will likely change in 5201 ** the near future and that SQLite should make its own private copy of 5202 ** the content before returning. 5203 ** 5204 ** The typedef is necessary to work around problems in certain 5205 ** C++ compilers. 5206 */ 5207 typedef void (*sqlite3_destructor_type)(void*); 5208 #define SQLITE_STATIC ((sqlite3_destructor_type)0) 5209 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5210 5211 /* 5212 ** CAPI3REF: Setting The Result Of An SQL Function 5213 ** METHOD: sqlite3_context 5214 ** 5215 ** These routines are used by the xFunc or xFinal callbacks that 5216 ** implement SQL functions and aggregates. See 5217 ** [sqlite3_create_function()] and [sqlite3_create_function16()] 5218 ** for additional information. 5219 ** 5220 ** These functions work very much like the [parameter binding] family of 5221 ** functions used to bind values to host parameters in prepared statements. 5222 ** Refer to the [SQL parameter] documentation for additional information. 5223 ** 5224 ** ^The sqlite3_result_blob() interface sets the result from 5225 ** an application-defined function to be the BLOB whose content is pointed 5226 ** to by the second parameter and which is N bytes long where N is the 5227 ** third parameter. 5228 ** 5229 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5230 ** interfaces set the result of the application-defined function to be 5231 ** a BLOB containing all zero bytes and N bytes in size. 5232 ** 5233 ** ^The sqlite3_result_double() interface sets the result from 5234 ** an application-defined function to be a floating point value specified 5235 ** by its 2nd argument. 5236 ** 5237 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5238 ** cause the implemented SQL function to throw an exception. 5239 ** ^SQLite uses the string pointed to by the 5240 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5241 ** as the text of an error message. ^SQLite interprets the error 5242 ** message string from sqlite3_result_error() as UTF-8. ^SQLite 5243 ** interprets the string from sqlite3_result_error16() as UTF-16 in native 5244 ** byte order. ^If the third parameter to sqlite3_result_error() 5245 ** or sqlite3_result_error16() is negative then SQLite takes as the error 5246 ** message all text up through the first zero character. 5247 ** ^If the third parameter to sqlite3_result_error() or 5248 ** sqlite3_result_error16() is non-negative then SQLite takes that many 5249 ** bytes (not characters) from the 2nd parameter as the error message. 5250 ** ^The sqlite3_result_error() and sqlite3_result_error16() 5251 ** routines make a private copy of the error message text before 5252 ** they return. Hence, the calling function can deallocate or 5253 ** modify the text after they return without harm. 5254 ** ^The sqlite3_result_error_code() function changes the error code 5255 ** returned by SQLite as a result of an error in a function. ^By default, 5256 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5257 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5258 ** 5259 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5260 ** error indicating that a string or BLOB is too long to represent. 5261 ** 5262 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5263 ** error indicating that a memory allocation failed. 5264 ** 5265 ** ^The sqlite3_result_int() interface sets the return value 5266 ** of the application-defined function to be the 32-bit signed integer 5267 ** value given in the 2nd argument. 5268 ** ^The sqlite3_result_int64() interface sets the return value 5269 ** of the application-defined function to be the 64-bit signed integer 5270 ** value given in the 2nd argument. 5271 ** 5272 ** ^The sqlite3_result_null() interface sets the return value 5273 ** of the application-defined function to be NULL. 5274 ** 5275 ** ^The sqlite3_result_text(), sqlite3_result_text16(), 5276 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5277 ** set the return value of the application-defined function to be 5278 ** a text string which is represented as UTF-8, UTF-16 native byte order, 5279 ** UTF-16 little endian, or UTF-16 big endian, respectively. 5280 ** ^The sqlite3_result_text64() interface sets the return value of an 5281 ** application-defined function to be a text string in an encoding 5282 ** specified by the fifth (and last) parameter, which must be one 5283 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5284 ** ^SQLite takes the text result from the application from 5285 ** the 2nd parameter of the sqlite3_result_text* interfaces. 5286 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5287 ** is negative, then SQLite takes result text from the 2nd parameter 5288 ** through the first zero character. 5289 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5290 ** is non-negative, then as many bytes (not characters) of the text 5291 ** pointed to by the 2nd parameter are taken as the application-defined 5292 ** function result. If the 3rd parameter is non-negative, then it 5293 ** must be the byte offset into the string where the NUL terminator would 5294 ** appear if the string where NUL terminated. If any NUL characters occur 5295 ** in the string at a byte offset that is less than the value of the 3rd 5296 ** parameter, then the resulting string will contain embedded NULs and the 5297 ** result of expressions operating on strings with embedded NULs is undefined. 5298 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5299 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5300 ** function as the destructor on the text or BLOB result when it has 5301 ** finished using that result. 5302 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5303 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5304 ** assumes that the text or BLOB result is in constant space and does not 5305 ** copy the content of the parameter nor call a destructor on the content 5306 ** when it has finished using that result. 5307 ** ^If the 4th parameter to the sqlite3_result_text* interfaces 5308 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5309 ** then SQLite makes a copy of the result into space obtained 5310 ** from [sqlite3_malloc()] before it returns. 5311 ** 5312 ** ^The sqlite3_result_value() interface sets the result of 5313 ** the application-defined function to be a copy of the 5314 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5315 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5316 ** so that the [sqlite3_value] specified in the parameter may change or 5317 ** be deallocated after sqlite3_result_value() returns without harm. 5318 ** ^A [protected sqlite3_value] object may always be used where an 5319 ** [unprotected sqlite3_value] object is required, so either 5320 ** kind of [sqlite3_value] object can be used with this interface. 5321 ** 5322 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5323 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5324 ** also associates the host-language pointer P or type T with that 5325 ** NULL value such that the pointer can be retrieved within an 5326 ** [application-defined SQL function] using [sqlite3_value_pointer()]. 5327 ** ^If the D parameter is not NULL, then it is a pointer to a destructor 5328 ** for the P parameter. ^SQLite invokes D with P as its only argument 5329 ** when SQLite is finished with P. The T parameter should be a static 5330 ** string and preferably a string literal. The sqlite3_result_pointer() 5331 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5332 ** 5333 ** If these routines are called from within the different thread 5334 ** than the one containing the application-defined function that received 5335 ** the [sqlite3_context] pointer, the results are undefined. 5336 */ 5337 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5338 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5339 sqlite3_uint64,void(*)(void*)); 5340 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5341 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5342 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5343 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5344 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5345 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5346 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5347 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5348 SQLITE_API void sqlite3_result_null(sqlite3_context*); 5349 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5350 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5351 void(*)(void*), unsigned char encoding); 5352 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5353 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5354 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5355 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5356 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5357 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5358 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5359 5360 5361 /* 5362 ** CAPI3REF: Setting The Subtype Of An SQL Function 5363 ** METHOD: sqlite3_context 5364 ** 5365 ** The sqlite3_result_subtype(C,T) function causes the subtype of 5366 ** the result from the [application-defined SQL function] with 5367 ** [sqlite3_context] C to be the value T. Only the lower 8 bits 5368 ** of the subtype T are preserved in current versions of SQLite; 5369 ** higher order bits are discarded. 5370 ** The number of subtype bytes preserved by SQLite might increase 5371 ** in future releases of SQLite. 5372 */ 5373 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5374 5375 /* 5376 ** CAPI3REF: Define New Collating Sequences 5377 ** METHOD: sqlite3 5378 ** 5379 ** ^These functions add, remove, or modify a [collation] associated 5380 ** with the [database connection] specified as the first argument. 5381 ** 5382 ** ^The name of the collation is a UTF-8 string 5383 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5384 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5385 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5386 ** considered to be the same name. 5387 ** 5388 ** ^(The third argument (eTextRep) must be one of the constants: 5389 ** <ul> 5390 ** <li> [SQLITE_UTF8], 5391 ** <li> [SQLITE_UTF16LE], 5392 ** <li> [SQLITE_UTF16BE], 5393 ** <li> [SQLITE_UTF16], or 5394 ** <li> [SQLITE_UTF16_ALIGNED]. 5395 ** </ul>)^ 5396 ** ^The eTextRep argument determines the encoding of strings passed 5397 ** to the collating function callback, xCallback. 5398 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5399 ** force strings to be UTF16 with native byte order. 5400 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5401 ** on an even byte address. 5402 ** 5403 ** ^The fourth argument, pArg, is an application data pointer that is passed 5404 ** through as the first argument to the collating function callback. 5405 ** 5406 ** ^The fifth argument, xCallback, is a pointer to the collating function. 5407 ** ^Multiple collating functions can be registered using the same name but 5408 ** with different eTextRep parameters and SQLite will use whichever 5409 ** function requires the least amount of data transformation. 5410 ** ^If the xCallback argument is NULL then the collating function is 5411 ** deleted. ^When all collating functions having the same name are deleted, 5412 ** that collation is no longer usable. 5413 ** 5414 ** ^The collating function callback is invoked with a copy of the pArg 5415 ** application data pointer and with two strings in the encoding specified 5416 ** by the eTextRep argument. The collating function must return an 5417 ** integer that is negative, zero, or positive 5418 ** if the first string is less than, equal to, or greater than the second, 5419 ** respectively. A collating function must always return the same answer 5420 ** given the same inputs. If two or more collating functions are registered 5421 ** to the same collation name (using different eTextRep values) then all 5422 ** must give an equivalent answer when invoked with equivalent strings. 5423 ** The collating function must obey the following properties for all 5424 ** strings A, B, and C: 5425 ** 5426 ** <ol> 5427 ** <li> If A==B then B==A. 5428 ** <li> If A==B and B==C then A==C. 5429 ** <li> If A<B THEN B>A. 5430 ** <li> If A<B and B<C then A<C. 5431 ** </ol> 5432 ** 5433 ** If a collating function fails any of the above constraints and that 5434 ** collating function is registered and used, then the behavior of SQLite 5435 ** is undefined. 5436 ** 5437 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5438 ** with the addition that the xDestroy callback is invoked on pArg when 5439 ** the collating function is deleted. 5440 ** ^Collating functions are deleted when they are overridden by later 5441 ** calls to the collation creation functions or when the 5442 ** [database connection] is closed using [sqlite3_close()]. 5443 ** 5444 ** ^The xDestroy callback is <u>not</u> called if the 5445 ** sqlite3_create_collation_v2() function fails. Applications that invoke 5446 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5447 ** check the return code and dispose of the application data pointer 5448 ** themselves rather than expecting SQLite to deal with it for them. 5449 ** This is different from every other SQLite interface. The inconsistency 5450 ** is unfortunate but cannot be changed without breaking backwards 5451 ** compatibility. 5452 ** 5453 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5454 */ 5455 SQLITE_API int sqlite3_create_collation( 5456 sqlite3*, 5457 const char *zName, 5458 int eTextRep, 5459 void *pArg, 5460 int(*xCompare)(void*,int,const void*,int,const void*) 5461 ); 5462 SQLITE_API int sqlite3_create_collation_v2( 5463 sqlite3*, 5464 const char *zName, 5465 int eTextRep, 5466 void *pArg, 5467 int(*xCompare)(void*,int,const void*,int,const void*), 5468 void(*xDestroy)(void*) 5469 ); 5470 SQLITE_API int sqlite3_create_collation16( 5471 sqlite3*, 5472 const void *zName, 5473 int eTextRep, 5474 void *pArg, 5475 int(*xCompare)(void*,int,const void*,int,const void*) 5476 ); 5477 5478 /* 5479 ** CAPI3REF: Collation Needed Callbacks 5480 ** METHOD: sqlite3 5481 ** 5482 ** ^To avoid having to register all collation sequences before a database 5483 ** can be used, a single callback function may be registered with the 5484 ** [database connection] to be invoked whenever an undefined collation 5485 ** sequence is required. 5486 ** 5487 ** ^If the function is registered using the sqlite3_collation_needed() API, 5488 ** then it is passed the names of undefined collation sequences as strings 5489 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5490 ** the names are passed as UTF-16 in machine native byte order. 5491 ** ^A call to either function replaces the existing collation-needed callback. 5492 ** 5493 ** ^(When the callback is invoked, the first argument passed is a copy 5494 ** of the second argument to sqlite3_collation_needed() or 5495 ** sqlite3_collation_needed16(). The second argument is the database 5496 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5497 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5498 ** sequence function required. The fourth parameter is the name of the 5499 ** required collation sequence.)^ 5500 ** 5501 ** The callback function should register the desired collation using 5502 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5503 ** [sqlite3_create_collation_v2()]. 5504 */ 5505 SQLITE_API int sqlite3_collation_needed( 5506 sqlite3*, 5507 void*, 5508 void(*)(void*,sqlite3*,int eTextRep,const char*) 5509 ); 5510 SQLITE_API int sqlite3_collation_needed16( 5511 sqlite3*, 5512 void*, 5513 void(*)(void*,sqlite3*,int eTextRep,const void*) 5514 ); 5515 5516 #ifdef SQLITE_HAS_CODEC 5517 /* 5518 ** Specify the key for an encrypted database. This routine should be 5519 ** called right after sqlite3_open(). 5520 ** 5521 ** The code to implement this API is not available in the public release 5522 ** of SQLite. 5523 */ 5524 SQLITE_API int sqlite3_key( 5525 sqlite3 *db, /* Database to be rekeyed */ 5526 const void *pKey, int nKey /* The key */ 5527 ); 5528 SQLITE_API int sqlite3_key_v2( 5529 sqlite3 *db, /* Database to be rekeyed */ 5530 const char *zDbName, /* Name of the database */ 5531 const void *pKey, int nKey /* The key */ 5532 ); 5533 5534 /* 5535 ** Change the key on an open database. If the current database is not 5536 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5537 ** database is decrypted. 5538 ** 5539 ** The code to implement this API is not available in the public release 5540 ** of SQLite. 5541 */ 5542 SQLITE_API int sqlite3_rekey( 5543 sqlite3 *db, /* Database to be rekeyed */ 5544 const void *pKey, int nKey /* The new key */ 5545 ); 5546 SQLITE_API int sqlite3_rekey_v2( 5547 sqlite3 *db, /* Database to be rekeyed */ 5548 const char *zDbName, /* Name of the database */ 5549 const void *pKey, int nKey /* The new key */ 5550 ); 5551 5552 /* 5553 ** Specify the activation key for a SEE database. Unless 5554 ** activated, none of the SEE routines will work. 5555 */ 5556 SQLITE_API void sqlite3_activate_see( 5557 const char *zPassPhrase /* Activation phrase */ 5558 ); 5559 #endif 5560 5561 #ifdef SQLITE_ENABLE_CEROD 5562 /* 5563 ** Specify the activation key for a CEROD database. Unless 5564 ** activated, none of the CEROD routines will work. 5565 */ 5566 SQLITE_API void sqlite3_activate_cerod( 5567 const char *zPassPhrase /* Activation phrase */ 5568 ); 5569 #endif 5570 5571 /* 5572 ** CAPI3REF: Suspend Execution For A Short Time 5573 ** 5574 ** The sqlite3_sleep() function causes the current thread to suspend execution 5575 ** for at least a number of milliseconds specified in its parameter. 5576 ** 5577 ** If the operating system does not support sleep requests with 5578 ** millisecond time resolution, then the time will be rounded up to 5579 ** the nearest second. The number of milliseconds of sleep actually 5580 ** requested from the operating system is returned. 5581 ** 5582 ** ^SQLite implements this interface by calling the xSleep() 5583 ** method of the default [sqlite3_vfs] object. If the xSleep() method 5584 ** of the default VFS is not implemented correctly, or not implemented at 5585 ** all, then the behavior of sqlite3_sleep() may deviate from the description 5586 ** in the previous paragraphs. 5587 */ 5588 SQLITE_API int sqlite3_sleep(int); 5589 5590 /* 5591 ** CAPI3REF: Name Of The Folder Holding Temporary Files 5592 ** 5593 ** ^(If this global variable is made to point to a string which is 5594 ** the name of a folder (a.k.a. directory), then all temporary files 5595 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5596 ** will be placed in that directory.)^ ^If this variable 5597 ** is a NULL pointer, then SQLite performs a search for an appropriate 5598 ** temporary file directory. 5599 ** 5600 ** Applications are strongly discouraged from using this global variable. 5601 ** It is required to set a temporary folder on Windows Runtime (WinRT). 5602 ** But for all other platforms, it is highly recommended that applications 5603 ** neither read nor write this variable. This global variable is a relic 5604 ** that exists for backwards compatibility of legacy applications and should 5605 ** be avoided in new projects. 5606 ** 5607 ** It is not safe to read or modify this variable in more than one 5608 ** thread at a time. It is not safe to read or modify this variable 5609 ** if a [database connection] is being used at the same time in a separate 5610 ** thread. 5611 ** It is intended that this variable be set once 5612 ** as part of process initialization and before any SQLite interface 5613 ** routines have been called and that this variable remain unchanged 5614 ** thereafter. 5615 ** 5616 ** ^The [temp_store_directory pragma] may modify this variable and cause 5617 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5618 ** the [temp_store_directory pragma] always assumes that any string 5619 ** that this variable points to is held in memory obtained from 5620 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5621 ** using [sqlite3_free]. 5622 ** Hence, if this variable is modified directly, either it should be 5623 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5624 ** or else the use of the [temp_store_directory pragma] should be avoided. 5625 ** Except when requested by the [temp_store_directory pragma], SQLite 5626 ** does not free the memory that sqlite3_temp_directory points to. If 5627 ** the application wants that memory to be freed, it must do 5628 ** so itself, taking care to only do so after all [database connection] 5629 ** objects have been destroyed. 5630 ** 5631 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5632 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5633 ** features that require the use of temporary files may fail. Here is an 5634 ** example of how to do this using C++ with the Windows Runtime: 5635 ** 5636 ** <blockquote><pre> 5637 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5638 ** TemporaryFolder->Path->Data(); 5639 ** char zPathBuf[MAX_PATH + 1]; 5640 ** memset(zPathBuf, 0, sizeof(zPathBuf)); 5641 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5642 ** NULL, NULL); 5643 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5644 ** </pre></blockquote> 5645 */ 5646 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 5647 5648 /* 5649 ** CAPI3REF: Name Of The Folder Holding Database Files 5650 ** 5651 ** ^(If this global variable is made to point to a string which is 5652 ** the name of a folder (a.k.a. directory), then all database files 5653 ** specified with a relative pathname and created or accessed by 5654 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5655 ** to be relative to that directory.)^ ^If this variable is a NULL 5656 ** pointer, then SQLite assumes that all database files specified 5657 ** with a relative pathname are relative to the current directory 5658 ** for the process. Only the windows VFS makes use of this global 5659 ** variable; it is ignored by the unix VFS. 5660 ** 5661 ** Changing the value of this variable while a database connection is 5662 ** open can result in a corrupt database. 5663 ** 5664 ** It is not safe to read or modify this variable in more than one 5665 ** thread at a time. It is not safe to read or modify this variable 5666 ** if a [database connection] is being used at the same time in a separate 5667 ** thread. 5668 ** It is intended that this variable be set once 5669 ** as part of process initialization and before any SQLite interface 5670 ** routines have been called and that this variable remain unchanged 5671 ** thereafter. 5672 ** 5673 ** ^The [data_store_directory pragma] may modify this variable and cause 5674 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5675 ** the [data_store_directory pragma] always assumes that any string 5676 ** that this variable points to is held in memory obtained from 5677 ** [sqlite3_malloc] and the pragma may attempt to free that memory 5678 ** using [sqlite3_free]. 5679 ** Hence, if this variable is modified directly, either it should be 5680 ** made NULL or made to point to memory obtained from [sqlite3_malloc] 5681 ** or else the use of the [data_store_directory pragma] should be avoided. 5682 */ 5683 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 5684 5685 /* 5686 ** CAPI3REF: Win32 Specific Interface 5687 ** 5688 ** These interfaces are available only on Windows. The 5689 ** [sqlite3_win32_set_directory] interface is used to set the value associated 5690 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5691 ** zValue, depending on the value of the type parameter. The zValue parameter 5692 ** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5693 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5694 ** prior to being used. The [sqlite3_win32_set_directory] interface returns 5695 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5696 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5697 ** [sqlite3_data_directory] variable is intended to act as a replacement for 5698 ** the current directory on the sub-platforms of Win32 where that concept is 5699 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5700 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5701 ** sqlite3_win32_set_directory interface except the string parameter must be 5702 ** UTF-8 or UTF-16, respectively. 5703 */ 5704 SQLITE_API int sqlite3_win32_set_directory( 5705 unsigned long type, /* Identifier for directory being set or reset */ 5706 void *zValue /* New value for directory being set or reset */ 5707 ); 5708 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5709 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5710 5711 /* 5712 ** CAPI3REF: Win32 Directory Types 5713 ** 5714 ** These macros are only available on Windows. They define the allowed values 5715 ** for the type argument to the [sqlite3_win32_set_directory] interface. 5716 */ 5717 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5718 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5719 5720 /* 5721 ** CAPI3REF: Test For Auto-Commit Mode 5722 ** KEYWORDS: {autocommit mode} 5723 ** METHOD: sqlite3 5724 ** 5725 ** ^The sqlite3_get_autocommit() interface returns non-zero or 5726 ** zero if the given database connection is or is not in autocommit mode, 5727 ** respectively. ^Autocommit mode is on by default. 5728 ** ^Autocommit mode is disabled by a [BEGIN] statement. 5729 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5730 ** 5731 ** If certain kinds of errors occur on a statement within a multi-statement 5732 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5733 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5734 ** transaction might be rolled back automatically. The only way to 5735 ** find out whether SQLite automatically rolled back the transaction after 5736 ** an error is to use this function. 5737 ** 5738 ** If another thread changes the autocommit status of the database 5739 ** connection while this routine is running, then the return value 5740 ** is undefined. 5741 */ 5742 SQLITE_API int sqlite3_get_autocommit(sqlite3*); 5743 5744 /* 5745 ** CAPI3REF: Find The Database Handle Of A Prepared Statement 5746 ** METHOD: sqlite3_stmt 5747 ** 5748 ** ^The sqlite3_db_handle interface returns the [database connection] handle 5749 ** to which a [prepared statement] belongs. ^The [database connection] 5750 ** returned by sqlite3_db_handle is the same [database connection] 5751 ** that was the first argument 5752 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5753 ** create the statement in the first place. 5754 */ 5755 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5756 5757 /* 5758 ** CAPI3REF: Return The Filename For A Database Connection 5759 ** METHOD: sqlite3 5760 ** 5761 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5762 ** associated with database N of connection D. ^The main database file 5763 ** has the name "main". If there is no attached database N on the database 5764 ** connection D, or if database N is a temporary or in-memory database, then 5765 ** a NULL pointer is returned. 5766 ** 5767 ** ^The filename returned by this function is the output of the 5768 ** xFullPathname method of the [VFS]. ^In other words, the filename 5769 ** will be an absolute pathname, even if the filename used 5770 ** to open the database originally was a URI or relative pathname. 5771 */ 5772 SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5773 5774 /* 5775 ** CAPI3REF: Determine if a database is read-only 5776 ** METHOD: sqlite3 5777 ** 5778 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5779 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5780 ** the name of a database on connection D. 5781 */ 5782 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5783 5784 /* 5785 ** CAPI3REF: Find the next prepared statement 5786 ** METHOD: sqlite3 5787 ** 5788 ** ^This interface returns a pointer to the next [prepared statement] after 5789 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5790 ** then this interface returns a pointer to the first prepared statement 5791 ** associated with the database connection pDb. ^If no prepared statement 5792 ** satisfies the conditions of this routine, it returns NULL. 5793 ** 5794 ** The [database connection] pointer D in a call to 5795 ** [sqlite3_next_stmt(D,S)] must refer to an open database 5796 ** connection and in particular must not be a NULL pointer. 5797 */ 5798 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5799 5800 /* 5801 ** CAPI3REF: Commit And Rollback Notification Callbacks 5802 ** METHOD: sqlite3 5803 ** 5804 ** ^The sqlite3_commit_hook() interface registers a callback 5805 ** function to be invoked whenever a transaction is [COMMIT | committed]. 5806 ** ^Any callback set by a previous call to sqlite3_commit_hook() 5807 ** for the same database connection is overridden. 5808 ** ^The sqlite3_rollback_hook() interface registers a callback 5809 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5810 ** ^Any callback set by a previous call to sqlite3_rollback_hook() 5811 ** for the same database connection is overridden. 5812 ** ^The pArg argument is passed through to the callback. 5813 ** ^If the callback on a commit hook function returns non-zero, 5814 ** then the commit is converted into a rollback. 5815 ** 5816 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5817 ** return the P argument from the previous call of the same function 5818 ** on the same [database connection] D, or NULL for 5819 ** the first call for each function on D. 5820 ** 5821 ** The commit and rollback hook callbacks are not reentrant. 5822 ** The callback implementation must not do anything that will modify 5823 ** the database connection that invoked the callback. Any actions 5824 ** to modify the database connection must be deferred until after the 5825 ** completion of the [sqlite3_step()] call that triggered the commit 5826 ** or rollback hook in the first place. 5827 ** Note that running any other SQL statements, including SELECT statements, 5828 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5829 ** the database connections for the meaning of "modify" in this paragraph. 5830 ** 5831 ** ^Registering a NULL function disables the callback. 5832 ** 5833 ** ^When the commit hook callback routine returns zero, the [COMMIT] 5834 ** operation is allowed to continue normally. ^If the commit hook 5835 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5836 ** ^The rollback hook is invoked on a rollback that results from a commit 5837 ** hook returning non-zero, just as it would be with any other rollback. 5838 ** 5839 ** ^For the purposes of this API, a transaction is said to have been 5840 ** rolled back if an explicit "ROLLBACK" statement is executed, or 5841 ** an error or constraint causes an implicit rollback to occur. 5842 ** ^The rollback callback is not invoked if a transaction is 5843 ** automatically rolled back because the database connection is closed. 5844 ** 5845 ** See also the [sqlite3_update_hook()] interface. 5846 */ 5847 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5848 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5849 5850 /* 5851 ** CAPI3REF: Data Change Notification Callbacks 5852 ** METHOD: sqlite3 5853 ** 5854 ** ^The sqlite3_update_hook() interface registers a callback function 5855 ** with the [database connection] identified by the first argument 5856 ** to be invoked whenever a row is updated, inserted or deleted in 5857 ** a [rowid table]. 5858 ** ^Any callback set by a previous call to this function 5859 ** for the same database connection is overridden. 5860 ** 5861 ** ^The second argument is a pointer to the function to invoke when a 5862 ** row is updated, inserted or deleted in a rowid table. 5863 ** ^The first argument to the callback is a copy of the third argument 5864 ** to sqlite3_update_hook(). 5865 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5866 ** or [SQLITE_UPDATE], depending on the operation that caused the callback 5867 ** to be invoked. 5868 ** ^The third and fourth arguments to the callback contain pointers to the 5869 ** database and table name containing the affected row. 5870 ** ^The final callback parameter is the [rowid] of the row. 5871 ** ^In the case of an update, this is the [rowid] after the update takes place. 5872 ** 5873 ** ^(The update hook is not invoked when internal system tables are 5874 ** modified (i.e. sqlite_master and sqlite_sequence).)^ 5875 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5876 ** 5877 ** ^In the current implementation, the update hook 5878 ** is not invoked when conflicting rows are deleted because of an 5879 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5880 ** invoked when rows are deleted using the [truncate optimization]. 5881 ** The exceptions defined in this paragraph might change in a future 5882 ** release of SQLite. 5883 ** 5884 ** The update hook implementation must not do anything that will modify 5885 ** the database connection that invoked the update hook. Any actions 5886 ** to modify the database connection must be deferred until after the 5887 ** completion of the [sqlite3_step()] call that triggered the update hook. 5888 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5889 ** database connections for the meaning of "modify" in this paragraph. 5890 ** 5891 ** ^The sqlite3_update_hook(D,C,P) function 5892 ** returns the P argument from the previous call 5893 ** on the same [database connection] D, or NULL for 5894 ** the first call on D. 5895 ** 5896 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5897 ** and [sqlite3_preupdate_hook()] interfaces. 5898 */ 5899 SQLITE_API void *sqlite3_update_hook( 5900 sqlite3*, 5901 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5902 void* 5903 ); 5904 5905 /* 5906 ** CAPI3REF: Enable Or Disable Shared Pager Cache 5907 ** 5908 ** ^(This routine enables or disables the sharing of the database cache 5909 ** and schema data structures between [database connection | connections] 5910 ** to the same database. Sharing is enabled if the argument is true 5911 ** and disabled if the argument is false.)^ 5912 ** 5913 ** ^Cache sharing is enabled and disabled for an entire process. 5914 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5915 ** In prior versions of SQLite, 5916 ** sharing was enabled or disabled for each thread separately. 5917 ** 5918 ** ^(The cache sharing mode set by this interface effects all subsequent 5919 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5920 ** Existing database connections continue use the sharing mode 5921 ** that was in effect at the time they were opened.)^ 5922 ** 5923 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5924 ** successfully. An [error code] is returned otherwise.)^ 5925 ** 5926 ** ^Shared cache is disabled by default. But this might change in 5927 ** future releases of SQLite. Applications that care about shared 5928 ** cache setting should set it explicitly. 5929 ** 5930 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5931 ** and will always return SQLITE_MISUSE. On those systems, 5932 ** shared cache mode should be enabled per-database connection via 5933 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5934 ** 5935 ** This interface is threadsafe on processors where writing a 5936 ** 32-bit integer is atomic. 5937 ** 5938 ** See Also: [SQLite Shared-Cache Mode] 5939 */ 5940 SQLITE_API int sqlite3_enable_shared_cache(int); 5941 5942 /* 5943 ** CAPI3REF: Attempt To Free Heap Memory 5944 ** 5945 ** ^The sqlite3_release_memory() interface attempts to free N bytes 5946 ** of heap memory by deallocating non-essential memory allocations 5947 ** held by the database library. Memory used to cache database 5948 ** pages to improve performance is an example of non-essential memory. 5949 ** ^sqlite3_release_memory() returns the number of bytes actually freed, 5950 ** which might be more or less than the amount requested. 5951 ** ^The sqlite3_release_memory() routine is a no-op returning zero 5952 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5953 ** 5954 ** See also: [sqlite3_db_release_memory()] 5955 */ 5956 SQLITE_API int sqlite3_release_memory(int); 5957 5958 /* 5959 ** CAPI3REF: Free Memory Used By A Database Connection 5960 ** METHOD: sqlite3 5961 ** 5962 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5963 ** memory as possible from database connection D. Unlike the 5964 ** [sqlite3_release_memory()] interface, this interface is in effect even 5965 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5966 ** omitted. 5967 ** 5968 ** See also: [sqlite3_release_memory()] 5969 */ 5970 SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5971 5972 /* 5973 ** CAPI3REF: Impose A Limit On Heap Size 5974 ** 5975 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5976 ** soft limit on the amount of heap memory that may be allocated by SQLite. 5977 ** ^SQLite strives to keep heap memory utilization below the soft heap 5978 ** limit by reducing the number of pages held in the page cache 5979 ** as heap memory usages approaches the limit. 5980 ** ^The soft heap limit is "soft" because even though SQLite strives to stay 5981 ** below the limit, it will exceed the limit rather than generate 5982 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5983 ** is advisory only. 5984 ** 5985 ** ^The return value from sqlite3_soft_heap_limit64() is the size of 5986 ** the soft heap limit prior to the call, or negative in the case of an 5987 ** error. ^If the argument N is negative 5988 ** then no change is made to the soft heap limit. Hence, the current 5989 ** size of the soft heap limit can be determined by invoking 5990 ** sqlite3_soft_heap_limit64() with a negative argument. 5991 ** 5992 ** ^If the argument N is zero then the soft heap limit is disabled. 5993 ** 5994 ** ^(The soft heap limit is not enforced in the current implementation 5995 ** if one or more of following conditions are true: 5996 ** 5997 ** <ul> 5998 ** <li> The soft heap limit is set to zero. 5999 ** <li> Memory accounting is disabled using a combination of the 6000 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6001 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6002 ** <li> An alternative page cache implementation is specified using 6003 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6004 ** <li> The page cache allocates from its own memory pool supplied 6005 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6006 ** from the heap. 6007 ** </ul>)^ 6008 ** 6009 ** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6010 ** the soft heap limit is enforced 6011 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6012 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6013 ** the soft heap limit is enforced on every memory allocation. Without 6014 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6015 ** when memory is allocated by the page cache. Testing suggests that because 6016 ** the page cache is the predominate memory user in SQLite, most 6017 ** applications will achieve adequate soft heap limit enforcement without 6018 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6019 ** 6020 ** The circumstances under which SQLite will enforce the soft heap limit may 6021 ** changes in future releases of SQLite. 6022 */ 6023 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6024 6025 /* 6026 ** CAPI3REF: Deprecated Soft Heap Limit Interface 6027 ** DEPRECATED 6028 ** 6029 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6030 ** interface. This routine is provided for historical compatibility 6031 ** only. All new applications should use the 6032 ** [sqlite3_soft_heap_limit64()] interface rather than this one. 6033 */ 6034 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6035 6036 6037 /* 6038 ** CAPI3REF: Extract Metadata About A Column Of A Table 6039 ** METHOD: sqlite3 6040 ** 6041 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6042 ** information about column C of table T in database D 6043 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6044 ** interface returns SQLITE_OK and fills in the non-NULL pointers in 6045 ** the final five arguments with appropriate values if the specified 6046 ** column exists. ^The sqlite3_table_column_metadata() interface returns 6047 ** SQLITE_ERROR and if the specified column does not exist. 6048 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6049 ** NULL pointer, then this routine simply checks for the existence of the 6050 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6051 ** does not. If the table name parameter T in a call to 6052 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6053 ** undefined behavior. 6054 ** 6055 ** ^The column is identified by the second, third and fourth parameters to 6056 ** this function. ^(The second parameter is either the name of the database 6057 ** (i.e. "main", "temp", or an attached database) containing the specified 6058 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6059 ** for the table using the same algorithm used by the database engine to 6060 ** resolve unqualified table references. 6061 ** 6062 ** ^The third and fourth parameters to this function are the table and column 6063 ** name of the desired column, respectively. 6064 ** 6065 ** ^Metadata is returned by writing to the memory locations passed as the 5th 6066 ** and subsequent parameters to this function. ^Any of these arguments may be 6067 ** NULL, in which case the corresponding element of metadata is omitted. 6068 ** 6069 ** ^(<blockquote> 6070 ** <table border="1"> 6071 ** <tr><th> Parameter <th> Output<br>Type <th> Description 6072 ** 6073 ** <tr><td> 5th <td> const char* <td> Data type 6074 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6075 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6076 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6077 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6078 ** </table> 6079 ** </blockquote>)^ 6080 ** 6081 ** ^The memory pointed to by the character pointers returned for the 6082 ** declaration type and collation sequence is valid until the next 6083 ** call to any SQLite API function. 6084 ** 6085 ** ^If the specified table is actually a view, an [error code] is returned. 6086 ** 6087 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6088 ** is not a [WITHOUT ROWID] table and an 6089 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6090 ** parameters are set for the explicitly declared column. ^(If there is no 6091 ** [INTEGER PRIMARY KEY] column, then the outputs 6092 ** for the [rowid] are set as follows: 6093 ** 6094 ** <pre> 6095 ** data type: "INTEGER" 6096 ** collation sequence: "BINARY" 6097 ** not null: 0 6098 ** primary key: 1 6099 ** auto increment: 0 6100 ** </pre>)^ 6101 ** 6102 ** ^This function causes all database schemas to be read from disk and 6103 ** parsed, if that has not already been done, and returns an error if 6104 ** any errors are encountered while loading the schema. 6105 */ 6106 SQLITE_API int sqlite3_table_column_metadata( 6107 sqlite3 *db, /* Connection handle */ 6108 const char *zDbName, /* Database name or NULL */ 6109 const char *zTableName, /* Table name */ 6110 const char *zColumnName, /* Column name */ 6111 char const **pzDataType, /* OUTPUT: Declared data type */ 6112 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6113 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6114 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6115 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6116 ); 6117 6118 /* 6119 ** CAPI3REF: Load An Extension 6120 ** METHOD: sqlite3 6121 ** 6122 ** ^This interface loads an SQLite extension library from the named file. 6123 ** 6124 ** ^The sqlite3_load_extension() interface attempts to load an 6125 ** [SQLite extension] library contained in the file zFile. If 6126 ** the file cannot be loaded directly, attempts are made to load 6127 ** with various operating-system specific extensions added. 6128 ** So for example, if "samplelib" cannot be loaded, then names like 6129 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6130 ** be tried also. 6131 ** 6132 ** ^The entry point is zProc. 6133 ** ^(zProc may be 0, in which case SQLite will try to come up with an 6134 ** entry point name on its own. It first tries "sqlite3_extension_init". 6135 ** If that does not work, it constructs a name "sqlite3_X_init" where the 6136 ** X is consists of the lower-case equivalent of all ASCII alphabetic 6137 ** characters in the filename from the last "/" to the first following 6138 ** "." and omitting any initial "lib".)^ 6139 ** ^The sqlite3_load_extension() interface returns 6140 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6141 ** ^If an error occurs and pzErrMsg is not 0, then the 6142 ** [sqlite3_load_extension()] interface shall attempt to 6143 ** fill *pzErrMsg with error message text stored in memory 6144 ** obtained from [sqlite3_malloc()]. The calling function 6145 ** should free this memory by calling [sqlite3_free()]. 6146 ** 6147 ** ^Extension loading must be enabled using 6148 ** [sqlite3_enable_load_extension()] or 6149 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6150 ** prior to calling this API, 6151 ** otherwise an error will be returned. 6152 ** 6153 ** <b>Security warning:</b> It is recommended that the 6154 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6155 ** interface. The use of the [sqlite3_enable_load_extension()] interface 6156 ** should be avoided. This will keep the SQL function [load_extension()] 6157 ** disabled and prevent SQL injections from giving attackers 6158 ** access to extension loading capabilities. 6159 ** 6160 ** See also the [load_extension() SQL function]. 6161 */ 6162 SQLITE_API int sqlite3_load_extension( 6163 sqlite3 *db, /* Load the extension into this database connection */ 6164 const char *zFile, /* Name of the shared library containing extension */ 6165 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6166 char **pzErrMsg /* Put error message here if not 0 */ 6167 ); 6168 6169 /* 6170 ** CAPI3REF: Enable Or Disable Extension Loading 6171 ** METHOD: sqlite3 6172 ** 6173 ** ^So as not to open security holes in older applications that are 6174 ** unprepared to deal with [extension loading], and as a means of disabling 6175 ** [extension loading] while evaluating user-entered SQL, the following API 6176 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6177 ** 6178 ** ^Extension loading is off by default. 6179 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6180 ** to turn extension loading on and call it with onoff==0 to turn 6181 ** it back off again. 6182 ** 6183 ** ^This interface enables or disables both the C-API 6184 ** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6185 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6186 ** to enable or disable only the C-API.)^ 6187 ** 6188 ** <b>Security warning:</b> It is recommended that extension loading 6189 ** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6190 ** rather than this interface, so the [load_extension()] SQL function 6191 ** remains disabled. This will prevent SQL injections from giving attackers 6192 ** access to extension loading capabilities. 6193 */ 6194 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6195 6196 /* 6197 ** CAPI3REF: Automatically Load Statically Linked Extensions 6198 ** 6199 ** ^This interface causes the xEntryPoint() function to be invoked for 6200 ** each new [database connection] that is created. The idea here is that 6201 ** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6202 ** that is to be automatically loaded into all new database connections. 6203 ** 6204 ** ^(Even though the function prototype shows that xEntryPoint() takes 6205 ** no arguments and returns void, SQLite invokes xEntryPoint() with three 6206 ** arguments and expects an integer result as if the signature of the 6207 ** entry point where as follows: 6208 ** 6209 ** <blockquote><pre> 6210 ** int xEntryPoint( 6211 ** sqlite3 *db, 6212 ** const char **pzErrMsg, 6213 ** const struct sqlite3_api_routines *pThunk 6214 ** ); 6215 ** </pre></blockquote>)^ 6216 ** 6217 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6218 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6219 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6220 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6221 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6222 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6223 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6224 ** 6225 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6226 ** on the list of automatic extensions is a harmless no-op. ^No entry point 6227 ** will be called more than once for each database connection that is opened. 6228 ** 6229 ** See also: [sqlite3_reset_auto_extension()] 6230 ** and [sqlite3_cancel_auto_extension()] 6231 */ 6232 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6233 6234 /* 6235 ** CAPI3REF: Cancel Automatic Extension Loading 6236 ** 6237 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6238 ** initialization routine X that was registered using a prior call to 6239 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6240 ** routine returns 1 if initialization routine X was successfully 6241 ** unregistered and it returns 0 if X was not on the list of initialization 6242 ** routines. 6243 */ 6244 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6245 6246 /* 6247 ** CAPI3REF: Reset Automatic Extension Loading 6248 ** 6249 ** ^This interface disables all automatic extensions previously 6250 ** registered using [sqlite3_auto_extension()]. 6251 */ 6252 SQLITE_API void sqlite3_reset_auto_extension(void); 6253 6254 /* 6255 ** The interface to the virtual-table mechanism is currently considered 6256 ** to be experimental. The interface might change in incompatible ways. 6257 ** If this is a problem for you, do not use the interface at this time. 6258 ** 6259 ** When the virtual-table mechanism stabilizes, we will declare the 6260 ** interface fixed, support it indefinitely, and remove this comment. 6261 */ 6262 6263 /* 6264 ** Structures used by the virtual table interface 6265 */ 6266 typedef struct sqlite3_vtab sqlite3_vtab; 6267 typedef struct sqlite3_index_info sqlite3_index_info; 6268 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6269 typedef struct sqlite3_module sqlite3_module; 6270 6271 /* 6272 ** CAPI3REF: Virtual Table Object 6273 ** KEYWORDS: sqlite3_module {virtual table module} 6274 ** 6275 ** This structure, sometimes called a "virtual table module", 6276 ** defines the implementation of a [virtual tables]. 6277 ** This structure consists mostly of methods for the module. 6278 ** 6279 ** ^A virtual table module is created by filling in a persistent 6280 ** instance of this structure and passing a pointer to that instance 6281 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6282 ** ^The registration remains valid until it is replaced by a different 6283 ** module or until the [database connection] closes. The content 6284 ** of this structure must not change while it is registered with 6285 ** any database connection. 6286 */ 6287 struct sqlite3_module { 6288 int iVersion; 6289 int (*xCreate)(sqlite3*, void *pAux, 6290 int argc, const char *const*argv, 6291 sqlite3_vtab **ppVTab, char**); 6292 int (*xConnect)(sqlite3*, void *pAux, 6293 int argc, const char *const*argv, 6294 sqlite3_vtab **ppVTab, char**); 6295 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6296 int (*xDisconnect)(sqlite3_vtab *pVTab); 6297 int (*xDestroy)(sqlite3_vtab *pVTab); 6298 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6299 int (*xClose)(sqlite3_vtab_cursor*); 6300 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6301 int argc, sqlite3_value **argv); 6302 int (*xNext)(sqlite3_vtab_cursor*); 6303 int (*xEof)(sqlite3_vtab_cursor*); 6304 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6305 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6306 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6307 int (*xBegin)(sqlite3_vtab *pVTab); 6308 int (*xSync)(sqlite3_vtab *pVTab); 6309 int (*xCommit)(sqlite3_vtab *pVTab); 6310 int (*xRollback)(sqlite3_vtab *pVTab); 6311 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6312 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6313 void **ppArg); 6314 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6315 /* The methods above are in version 1 of the sqlite_module object. Those 6316 ** below are for version 2 and greater. */ 6317 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6318 int (*xRelease)(sqlite3_vtab *pVTab, int); 6319 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6320 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6321 ** Those below are for version 3 and greater. */ 6322 int (*xShadowName)(const char*); 6323 }; 6324 6325 /* 6326 ** CAPI3REF: Virtual Table Indexing Information 6327 ** KEYWORDS: sqlite3_index_info 6328 ** 6329 ** The sqlite3_index_info structure and its substructures is used as part 6330 ** of the [virtual table] interface to 6331 ** pass information into and receive the reply from the [xBestIndex] 6332 ** method of a [virtual table module]. The fields under **Inputs** are the 6333 ** inputs to xBestIndex and are read-only. xBestIndex inserts its 6334 ** results into the **Outputs** fields. 6335 ** 6336 ** ^(The aConstraint[] array records WHERE clause constraints of the form: 6337 ** 6338 ** <blockquote>column OP expr</blockquote> 6339 ** 6340 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6341 ** stored in aConstraint[].op using one of the 6342 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6343 ** ^(The index of the column is stored in 6344 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6345 ** expr on the right-hand side can be evaluated (and thus the constraint 6346 ** is usable) and false if it cannot.)^ 6347 ** 6348 ** ^The optimizer automatically inverts terms of the form "expr OP column" 6349 ** and makes other simplifications to the WHERE clause in an attempt to 6350 ** get as many WHERE clause terms into the form shown above as possible. 6351 ** ^The aConstraint[] array only reports WHERE clause terms that are 6352 ** relevant to the particular virtual table being queried. 6353 ** 6354 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6355 ** ^Each term of aOrderBy records a column of the ORDER BY clause. 6356 ** 6357 ** The colUsed field indicates which columns of the virtual table may be 6358 ** required by the current scan. Virtual table columns are numbered from 6359 ** zero in the order in which they appear within the CREATE TABLE statement 6360 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6361 ** the corresponding bit is set within the colUsed mask if the column may be 6362 ** required by SQLite. If the table has at least 64 columns and any column 6363 ** to the right of the first 63 is required, then bit 63 of colUsed is also 6364 ** set. In other words, column iCol may be required if the expression 6365 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6366 ** non-zero. 6367 ** 6368 ** The [xBestIndex] method must fill aConstraintUsage[] with information 6369 ** about what parameters to pass to xFilter. ^If argvIndex>0 then 6370 ** the right-hand side of the corresponding aConstraint[] is evaluated 6371 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6372 ** is true, then the constraint is assumed to be fully handled by the 6373 ** virtual table and is not checked again by SQLite.)^ 6374 ** 6375 ** ^The idxNum and idxPtr values are recorded and passed into the 6376 ** [xFilter] method. 6377 ** ^[sqlite3_free()] is used to free idxPtr if and only if 6378 ** needToFreeIdxPtr is true. 6379 ** 6380 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6381 ** the correct order to satisfy the ORDER BY clause so that no separate 6382 ** sorting step is required. 6383 ** 6384 ** ^The estimatedCost value is an estimate of the cost of a particular 6385 ** strategy. A cost of N indicates that the cost of the strategy is similar 6386 ** to a linear scan of an SQLite table with N rows. A cost of log(N) 6387 ** indicates that the expense of the operation is similar to that of a 6388 ** binary search on a unique indexed field of an SQLite table with N rows. 6389 ** 6390 ** ^The estimatedRows value is an estimate of the number of rows that 6391 ** will be returned by the strategy. 6392 ** 6393 ** The xBestIndex method may optionally populate the idxFlags field with a 6394 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6395 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6396 ** assumes that the strategy may visit at most one row. 6397 ** 6398 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6399 ** SQLite also assumes that if a call to the xUpdate() method is made as 6400 ** part of the same statement to delete or update a virtual table row and the 6401 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6402 ** any database changes. In other words, if the xUpdate() returns 6403 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6404 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6405 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6406 ** the xUpdate method are automatically rolled back by SQLite. 6407 ** 6408 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6409 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6410 ** If a virtual table extension is 6411 ** used with an SQLite version earlier than 3.8.2, the results of attempting 6412 ** to read or write the estimatedRows field are undefined (but are likely 6413 ** to included crashing the application). The estimatedRows field should 6414 ** therefore only be used if [sqlite3_libversion_number()] returns a 6415 ** value greater than or equal to 3008002. Similarly, the idxFlags field 6416 ** was added for [version 3.9.0] ([dateof:3.9.0]). 6417 ** It may therefore only be used if 6418 ** sqlite3_libversion_number() returns a value greater than or equal to 6419 ** 3009000. 6420 */ 6421 struct sqlite3_index_info { 6422 /* Inputs */ 6423 int nConstraint; /* Number of entries in aConstraint */ 6424 struct sqlite3_index_constraint { 6425 int iColumn; /* Column constrained. -1 for ROWID */ 6426 unsigned char op; /* Constraint operator */ 6427 unsigned char usable; /* True if this constraint is usable */ 6428 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6429 } *aConstraint; /* Table of WHERE clause constraints */ 6430 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6431 struct sqlite3_index_orderby { 6432 int iColumn; /* Column number */ 6433 unsigned char desc; /* True for DESC. False for ASC. */ 6434 } *aOrderBy; /* The ORDER BY clause */ 6435 /* Outputs */ 6436 struct sqlite3_index_constraint_usage { 6437 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6438 unsigned char omit; /* Do not code a test for this constraint */ 6439 } *aConstraintUsage; 6440 int idxNum; /* Number used to identify the index */ 6441 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6442 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6443 int orderByConsumed; /* True if output is already ordered */ 6444 double estimatedCost; /* Estimated cost of using this index */ 6445 /* Fields below are only available in SQLite 3.8.2 and later */ 6446 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6447 /* Fields below are only available in SQLite 3.9.0 and later */ 6448 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6449 /* Fields below are only available in SQLite 3.10.0 and later */ 6450 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6451 }; 6452 6453 /* 6454 ** CAPI3REF: Virtual Table Scan Flags 6455 ** 6456 ** Virtual table implementations are allowed to set the 6457 ** [sqlite3_index_info].idxFlags field to some combination of 6458 ** these bits. 6459 */ 6460 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6461 6462 /* 6463 ** CAPI3REF: Virtual Table Constraint Operator Codes 6464 ** 6465 ** These macros defined the allowed values for the 6466 ** [sqlite3_index_info].aConstraint[].op field. Each value represents 6467 ** an operator that is part of a constraint term in the wHERE clause of 6468 ** a query that uses a [virtual table]. 6469 */ 6470 #define SQLITE_INDEX_CONSTRAINT_EQ 2 6471 #define SQLITE_INDEX_CONSTRAINT_GT 4 6472 #define SQLITE_INDEX_CONSTRAINT_LE 8 6473 #define SQLITE_INDEX_CONSTRAINT_LT 16 6474 #define SQLITE_INDEX_CONSTRAINT_GE 32 6475 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 6476 #define SQLITE_INDEX_CONSTRAINT_LIKE 65 6477 #define SQLITE_INDEX_CONSTRAINT_GLOB 66 6478 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6479 #define SQLITE_INDEX_CONSTRAINT_NE 68 6480 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6481 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6482 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6483 #define SQLITE_INDEX_CONSTRAINT_IS 72 6484 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6485 6486 /* 6487 ** CAPI3REF: Register A Virtual Table Implementation 6488 ** METHOD: sqlite3 6489 ** 6490 ** ^These routines are used to register a new [virtual table module] name. 6491 ** ^Module names must be registered before 6492 ** creating a new [virtual table] using the module and before using a 6493 ** preexisting [virtual table] for the module. 6494 ** 6495 ** ^The module name is registered on the [database connection] specified 6496 ** by the first parameter. ^The name of the module is given by the 6497 ** second parameter. ^The third parameter is a pointer to 6498 ** the implementation of the [virtual table module]. ^The fourth 6499 ** parameter is an arbitrary client data pointer that is passed through 6500 ** into the [xCreate] and [xConnect] methods of the virtual table module 6501 ** when a new virtual table is be being created or reinitialized. 6502 ** 6503 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6504 ** is a pointer to a destructor for the pClientData. ^SQLite will 6505 ** invoke the destructor function (if it is not NULL) when SQLite 6506 ** no longer needs the pClientData pointer. ^The destructor will also 6507 ** be invoked if the call to sqlite3_create_module_v2() fails. 6508 ** ^The sqlite3_create_module() 6509 ** interface is equivalent to sqlite3_create_module_v2() with a NULL 6510 ** destructor. 6511 */ 6512 SQLITE_API int sqlite3_create_module( 6513 sqlite3 *db, /* SQLite connection to register module with */ 6514 const char *zName, /* Name of the module */ 6515 const sqlite3_module *p, /* Methods for the module */ 6516 void *pClientData /* Client data for xCreate/xConnect */ 6517 ); 6518 SQLITE_API int sqlite3_create_module_v2( 6519 sqlite3 *db, /* SQLite connection to register module with */ 6520 const char *zName, /* Name of the module */ 6521 const sqlite3_module *p, /* Methods for the module */ 6522 void *pClientData, /* Client data for xCreate/xConnect */ 6523 void(*xDestroy)(void*) /* Module destructor function */ 6524 ); 6525 6526 /* 6527 ** CAPI3REF: Virtual Table Instance Object 6528 ** KEYWORDS: sqlite3_vtab 6529 ** 6530 ** Every [virtual table module] implementation uses a subclass 6531 ** of this object to describe a particular instance 6532 ** of the [virtual table]. Each subclass will 6533 ** be tailored to the specific needs of the module implementation. 6534 ** The purpose of this superclass is to define certain fields that are 6535 ** common to all module implementations. 6536 ** 6537 ** ^Virtual tables methods can set an error message by assigning a 6538 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6539 ** take care that any prior string is freed by a call to [sqlite3_free()] 6540 ** prior to assigning a new string to zErrMsg. ^After the error message 6541 ** is delivered up to the client application, the string will be automatically 6542 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6543 */ 6544 struct sqlite3_vtab { 6545 const sqlite3_module *pModule; /* The module for this virtual table */ 6546 int nRef; /* Number of open cursors */ 6547 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6548 /* Virtual table implementations will typically add additional fields */ 6549 }; 6550 6551 /* 6552 ** CAPI3REF: Virtual Table Cursor Object 6553 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6554 ** 6555 ** Every [virtual table module] implementation uses a subclass of the 6556 ** following structure to describe cursors that point into the 6557 ** [virtual table] and are used 6558 ** to loop through the virtual table. Cursors are created using the 6559 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6560 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6561 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6562 ** of the module. Each module implementation will define 6563 ** the content of a cursor structure to suit its own needs. 6564 ** 6565 ** This superclass exists in order to define fields of the cursor that 6566 ** are common to all implementations. 6567 */ 6568 struct sqlite3_vtab_cursor { 6569 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6570 /* Virtual table implementations will typically add additional fields */ 6571 }; 6572 6573 /* 6574 ** CAPI3REF: Declare The Schema Of A Virtual Table 6575 ** 6576 ** ^The [xCreate] and [xConnect] methods of a 6577 ** [virtual table module] call this interface 6578 ** to declare the format (the names and datatypes of the columns) of 6579 ** the virtual tables they implement. 6580 */ 6581 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6582 6583 /* 6584 ** CAPI3REF: Overload A Function For A Virtual Table 6585 ** METHOD: sqlite3 6586 ** 6587 ** ^(Virtual tables can provide alternative implementations of functions 6588 ** using the [xFindFunction] method of the [virtual table module]. 6589 ** But global versions of those functions 6590 ** must exist in order to be overloaded.)^ 6591 ** 6592 ** ^(This API makes sure a global version of a function with a particular 6593 ** name and number of parameters exists. If no such function exists 6594 ** before this API is called, a new function is created.)^ ^The implementation 6595 ** of the new function always causes an exception to be thrown. So 6596 ** the new function is not good for anything by itself. Its only 6597 ** purpose is to be a placeholder function that can be overloaded 6598 ** by a [virtual table]. 6599 */ 6600 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6601 6602 /* 6603 ** The interface to the virtual-table mechanism defined above (back up 6604 ** to a comment remarkably similar to this one) is currently considered 6605 ** to be experimental. The interface might change in incompatible ways. 6606 ** If this is a problem for you, do not use the interface at this time. 6607 ** 6608 ** When the virtual-table mechanism stabilizes, we will declare the 6609 ** interface fixed, support it indefinitely, and remove this comment. 6610 */ 6611 6612 /* 6613 ** CAPI3REF: A Handle To An Open BLOB 6614 ** KEYWORDS: {BLOB handle} {BLOB handles} 6615 ** 6616 ** An instance of this object represents an open BLOB on which 6617 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6618 ** ^Objects of this type are created by [sqlite3_blob_open()] 6619 ** and destroyed by [sqlite3_blob_close()]. 6620 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6621 ** can be used to read or write small subsections of the BLOB. 6622 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6623 */ 6624 typedef struct sqlite3_blob sqlite3_blob; 6625 6626 /* 6627 ** CAPI3REF: Open A BLOB For Incremental I/O 6628 ** METHOD: sqlite3 6629 ** CONSTRUCTOR: sqlite3_blob 6630 ** 6631 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6632 ** in row iRow, column zColumn, table zTable in database zDb; 6633 ** in other words, the same BLOB that would be selected by: 6634 ** 6635 ** <pre> 6636 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6637 ** </pre>)^ 6638 ** 6639 ** ^(Parameter zDb is not the filename that contains the database, but 6640 ** rather the symbolic name of the database. For attached databases, this is 6641 ** the name that appears after the AS keyword in the [ATTACH] statement. 6642 ** For the main database file, the database name is "main". For TEMP 6643 ** tables, the database name is "temp".)^ 6644 ** 6645 ** ^If the flags parameter is non-zero, then the BLOB is opened for read 6646 ** and write access. ^If the flags parameter is zero, the BLOB is opened for 6647 ** read-only access. 6648 ** 6649 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6650 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6651 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6652 ** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6653 ** on *ppBlob after this function it returns. 6654 ** 6655 ** This function fails with SQLITE_ERROR if any of the following are true: 6656 ** <ul> 6657 ** <li> ^(Database zDb does not exist)^, 6658 ** <li> ^(Table zTable does not exist within database zDb)^, 6659 ** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6660 ** <li> ^(Column zColumn does not exist)^, 6661 ** <li> ^(Row iRow is not present in the table)^, 6662 ** <li> ^(The specified column of row iRow contains a value that is not 6663 ** a TEXT or BLOB value)^, 6664 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6665 ** constraint and the blob is being opened for read/write access)^, 6666 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6667 ** column zColumn is part of a [child key] definition and the blob is 6668 ** being opened for read/write access)^. 6669 ** </ul> 6670 ** 6671 ** ^Unless it returns SQLITE_MISUSE, this function sets the 6672 ** [database connection] error code and message accessible via 6673 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6674 ** 6675 ** A BLOB referenced by sqlite3_blob_open() may be read using the 6676 ** [sqlite3_blob_read()] interface and modified by using 6677 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6678 ** different row of the same table using the [sqlite3_blob_reopen()] 6679 ** interface. However, the column, table, or database of a [BLOB handle] 6680 ** cannot be changed after the [BLOB handle] is opened. 6681 ** 6682 ** ^(If the row that a BLOB handle points to is modified by an 6683 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6684 ** then the BLOB handle is marked as "expired". 6685 ** This is true if any column of the row is changed, even a column 6686 ** other than the one the BLOB handle is open on.)^ 6687 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6688 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6689 ** ^(Changes written into a BLOB prior to the BLOB expiring are not 6690 ** rolled back by the expiration of the BLOB. Such changes will eventually 6691 ** commit if the transaction continues to completion.)^ 6692 ** 6693 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6694 ** the opened blob. ^The size of a blob may not be changed by this 6695 ** interface. Use the [UPDATE] SQL command to change the size of a 6696 ** blob. 6697 ** 6698 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6699 ** and the built-in [zeroblob] SQL function may be used to create a 6700 ** zero-filled blob to read or write using the incremental-blob interface. 6701 ** 6702 ** To avoid a resource leak, every open [BLOB handle] should eventually 6703 ** be released by a call to [sqlite3_blob_close()]. 6704 ** 6705 ** See also: [sqlite3_blob_close()], 6706 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6707 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6708 */ 6709 SQLITE_API int sqlite3_blob_open( 6710 sqlite3*, 6711 const char *zDb, 6712 const char *zTable, 6713 const char *zColumn, 6714 sqlite3_int64 iRow, 6715 int flags, 6716 sqlite3_blob **ppBlob 6717 ); 6718 6719 /* 6720 ** CAPI3REF: Move a BLOB Handle to a New Row 6721 ** METHOD: sqlite3_blob 6722 ** 6723 ** ^This function is used to move an existing [BLOB handle] so that it points 6724 ** to a different row of the same database table. ^The new row is identified 6725 ** by the rowid value passed as the second argument. Only the row can be 6726 ** changed. ^The database, table and column on which the blob handle is open 6727 ** remain the same. Moving an existing [BLOB handle] to a new row is 6728 ** faster than closing the existing handle and opening a new one. 6729 ** 6730 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6731 ** it must exist and there must be either a blob or text value stored in 6732 ** the nominated column.)^ ^If the new row is not present in the table, or if 6733 ** it does not contain a blob or text value, or if another error occurs, an 6734 ** SQLite error code is returned and the blob handle is considered aborted. 6735 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6736 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6737 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6738 ** always returns zero. 6739 ** 6740 ** ^This function sets the database handle error code and message. 6741 */ 6742 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6743 6744 /* 6745 ** CAPI3REF: Close A BLOB Handle 6746 ** DESTRUCTOR: sqlite3_blob 6747 ** 6748 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6749 ** unconditionally. Even if this routine returns an error code, the 6750 ** handle is still closed.)^ 6751 ** 6752 ** ^If the blob handle being closed was opened for read-write access, and if 6753 ** the database is in auto-commit mode and there are no other open read-write 6754 ** blob handles or active write statements, the current transaction is 6755 ** committed. ^If an error occurs while committing the transaction, an error 6756 ** code is returned and the transaction rolled back. 6757 ** 6758 ** Calling this function with an argument that is not a NULL pointer or an 6759 ** open blob handle results in undefined behaviour. ^Calling this routine 6760 ** with a null pointer (such as would be returned by a failed call to 6761 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6762 ** is passed a valid open blob handle, the values returned by the 6763 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6764 */ 6765 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 6766 6767 /* 6768 ** CAPI3REF: Return The Size Of An Open BLOB 6769 ** METHOD: sqlite3_blob 6770 ** 6771 ** ^Returns the size in bytes of the BLOB accessible via the 6772 ** successfully opened [BLOB handle] in its only argument. ^The 6773 ** incremental blob I/O routines can only read or overwriting existing 6774 ** blob content; they cannot change the size of a blob. 6775 ** 6776 ** This routine only works on a [BLOB handle] which has been created 6777 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6778 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6779 ** to this routine results in undefined and probably undesirable behavior. 6780 */ 6781 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 6782 6783 /* 6784 ** CAPI3REF: Read Data From A BLOB Incrementally 6785 ** METHOD: sqlite3_blob 6786 ** 6787 ** ^(This function is used to read data from an open [BLOB handle] into a 6788 ** caller-supplied buffer. N bytes of data are copied into buffer Z 6789 ** from the open BLOB, starting at offset iOffset.)^ 6790 ** 6791 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6792 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6793 ** less than zero, [SQLITE_ERROR] is returned and no data is read. 6794 ** ^The size of the blob (and hence the maximum value of N+iOffset) 6795 ** can be determined using the [sqlite3_blob_bytes()] interface. 6796 ** 6797 ** ^An attempt to read from an expired [BLOB handle] fails with an 6798 ** error code of [SQLITE_ABORT]. 6799 ** 6800 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6801 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6802 ** 6803 ** This routine only works on a [BLOB handle] which has been created 6804 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6805 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6806 ** to this routine results in undefined and probably undesirable behavior. 6807 ** 6808 ** See also: [sqlite3_blob_write()]. 6809 */ 6810 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6811 6812 /* 6813 ** CAPI3REF: Write Data Into A BLOB Incrementally 6814 ** METHOD: sqlite3_blob 6815 ** 6816 ** ^(This function is used to write data into an open [BLOB handle] from a 6817 ** caller-supplied buffer. N bytes of data are copied from the buffer Z 6818 ** into the open BLOB, starting at offset iOffset.)^ 6819 ** 6820 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6821 ** Otherwise, an [error code] or an [extended error code] is returned.)^ 6822 ** ^Unless SQLITE_MISUSE is returned, this function sets the 6823 ** [database connection] error code and message accessible via 6824 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6825 ** 6826 ** ^If the [BLOB handle] passed as the first argument was not opened for 6827 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6828 ** this function returns [SQLITE_READONLY]. 6829 ** 6830 ** This function may only modify the contents of the BLOB; it is 6831 ** not possible to increase the size of a BLOB using this API. 6832 ** ^If offset iOffset is less than N bytes from the end of the BLOB, 6833 ** [SQLITE_ERROR] is returned and no data is written. The size of the 6834 ** BLOB (and hence the maximum value of N+iOffset) can be determined 6835 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6836 ** than zero [SQLITE_ERROR] is returned and no data is written. 6837 ** 6838 ** ^An attempt to write to an expired [BLOB handle] fails with an 6839 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6840 ** before the [BLOB handle] expired are not rolled back by the 6841 ** expiration of the handle, though of course those changes might 6842 ** have been overwritten by the statement that expired the BLOB handle 6843 ** or by other independent statements. 6844 ** 6845 ** This routine only works on a [BLOB handle] which has been created 6846 ** by a prior successful call to [sqlite3_blob_open()] and which has not 6847 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6848 ** to this routine results in undefined and probably undesirable behavior. 6849 ** 6850 ** See also: [sqlite3_blob_read()]. 6851 */ 6852 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6853 6854 /* 6855 ** CAPI3REF: Virtual File System Objects 6856 ** 6857 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6858 ** that SQLite uses to interact 6859 ** with the underlying operating system. Most SQLite builds come with a 6860 ** single default VFS that is appropriate for the host computer. 6861 ** New VFSes can be registered and existing VFSes can be unregistered. 6862 ** The following interfaces are provided. 6863 ** 6864 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6865 ** ^Names are case sensitive. 6866 ** ^Names are zero-terminated UTF-8 strings. 6867 ** ^If there is no match, a NULL pointer is returned. 6868 ** ^If zVfsName is NULL then the default VFS is returned. 6869 ** 6870 ** ^New VFSes are registered with sqlite3_vfs_register(). 6871 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6872 ** ^The same VFS can be registered multiple times without injury. 6873 ** ^To make an existing VFS into the default VFS, register it again 6874 ** with the makeDflt flag set. If two different VFSes with the 6875 ** same name are registered, the behavior is undefined. If a 6876 ** VFS is registered with a name that is NULL or an empty string, 6877 ** then the behavior is undefined. 6878 ** 6879 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6880 ** ^(If the default VFS is unregistered, another VFS is chosen as 6881 ** the default. The choice for the new VFS is arbitrary.)^ 6882 */ 6883 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6884 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6885 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 6886 6887 /* 6888 ** CAPI3REF: Mutexes 6889 ** 6890 ** The SQLite core uses these routines for thread 6891 ** synchronization. Though they are intended for internal 6892 ** use by SQLite, code that links against SQLite is 6893 ** permitted to use any of these routines. 6894 ** 6895 ** The SQLite source code contains multiple implementations 6896 ** of these mutex routines. An appropriate implementation 6897 ** is selected automatically at compile-time. The following 6898 ** implementations are available in the SQLite core: 6899 ** 6900 ** <ul> 6901 ** <li> SQLITE_MUTEX_PTHREADS 6902 ** <li> SQLITE_MUTEX_W32 6903 ** <li> SQLITE_MUTEX_NOOP 6904 ** </ul> 6905 ** 6906 ** The SQLITE_MUTEX_NOOP implementation is a set of routines 6907 ** that does no real locking and is appropriate for use in 6908 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6909 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6910 ** and Windows. 6911 ** 6912 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6913 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6914 ** implementation is included with the library. In this case the 6915 ** application must supply a custom mutex implementation using the 6916 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6917 ** before calling sqlite3_initialize() or any other public sqlite3_ 6918 ** function that calls sqlite3_initialize(). 6919 ** 6920 ** ^The sqlite3_mutex_alloc() routine allocates a new 6921 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6922 ** routine returns NULL if it is unable to allocate the requested 6923 ** mutex. The argument to sqlite3_mutex_alloc() must one of these 6924 ** integer constants: 6925 ** 6926 ** <ul> 6927 ** <li> SQLITE_MUTEX_FAST 6928 ** <li> SQLITE_MUTEX_RECURSIVE 6929 ** <li> SQLITE_MUTEX_STATIC_MASTER 6930 ** <li> SQLITE_MUTEX_STATIC_MEM 6931 ** <li> SQLITE_MUTEX_STATIC_OPEN 6932 ** <li> SQLITE_MUTEX_STATIC_PRNG 6933 ** <li> SQLITE_MUTEX_STATIC_LRU 6934 ** <li> SQLITE_MUTEX_STATIC_PMEM 6935 ** <li> SQLITE_MUTEX_STATIC_APP1 6936 ** <li> SQLITE_MUTEX_STATIC_APP2 6937 ** <li> SQLITE_MUTEX_STATIC_APP3 6938 ** <li> SQLITE_MUTEX_STATIC_VFS1 6939 ** <li> SQLITE_MUTEX_STATIC_VFS2 6940 ** <li> SQLITE_MUTEX_STATIC_VFS3 6941 ** </ul> 6942 ** 6943 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6944 ** cause sqlite3_mutex_alloc() to create 6945 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6946 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6947 ** The mutex implementation does not need to make a distinction 6948 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6949 ** not want to. SQLite will only request a recursive mutex in 6950 ** cases where it really needs one. If a faster non-recursive mutex 6951 ** implementation is available on the host platform, the mutex subsystem 6952 ** might return such a mutex in response to SQLITE_MUTEX_FAST. 6953 ** 6954 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6955 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6956 ** a pointer to a static preexisting mutex. ^Nine static mutexes are 6957 ** used by the current version of SQLite. Future versions of SQLite 6958 ** may add additional static mutexes. Static mutexes are for internal 6959 ** use by SQLite only. Applications that use SQLite mutexes should 6960 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6961 ** SQLITE_MUTEX_RECURSIVE. 6962 ** 6963 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6964 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6965 ** returns a different mutex on every call. ^For the static 6966 ** mutex types, the same mutex is returned on every call that has 6967 ** the same type number. 6968 ** 6969 ** ^The sqlite3_mutex_free() routine deallocates a previously 6970 ** allocated dynamic mutex. Attempting to deallocate a static 6971 ** mutex results in undefined behavior. 6972 ** 6973 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6974 ** to enter a mutex. ^If another thread is already within the mutex, 6975 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6976 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6977 ** upon successful entry. ^(Mutexes created using 6978 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6979 ** In such cases, the 6980 ** mutex must be exited an equal number of times before another thread 6981 ** can enter.)^ If the same thread tries to enter any mutex other 6982 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6983 ** 6984 ** ^(Some systems (for example, Windows 95) do not support the operation 6985 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6986 ** will always return SQLITE_BUSY. The SQLite core only ever uses 6987 ** sqlite3_mutex_try() as an optimization so this is acceptable 6988 ** behavior.)^ 6989 ** 6990 ** ^The sqlite3_mutex_leave() routine exits a mutex that was 6991 ** previously entered by the same thread. The behavior 6992 ** is undefined if the mutex is not currently entered by the 6993 ** calling thread or is not currently allocated. 6994 ** 6995 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6996 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6997 ** behave as no-ops. 6998 ** 6999 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7000 */ 7001 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7002 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7003 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7004 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7005 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7006 7007 /* 7008 ** CAPI3REF: Mutex Methods Object 7009 ** 7010 ** An instance of this structure defines the low-level routines 7011 ** used to allocate and use mutexes. 7012 ** 7013 ** Usually, the default mutex implementations provided by SQLite are 7014 ** sufficient, however the application has the option of substituting a custom 7015 ** implementation for specialized deployments or systems for which SQLite 7016 ** does not provide a suitable implementation. In this case, the application 7017 ** creates and populates an instance of this structure to pass 7018 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7019 ** Additionally, an instance of this structure can be used as an 7020 ** output variable when querying the system for the current mutex 7021 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7022 ** 7023 ** ^The xMutexInit method defined by this structure is invoked as 7024 ** part of system initialization by the sqlite3_initialize() function. 7025 ** ^The xMutexInit routine is called by SQLite exactly once for each 7026 ** effective call to [sqlite3_initialize()]. 7027 ** 7028 ** ^The xMutexEnd method defined by this structure is invoked as 7029 ** part of system shutdown by the sqlite3_shutdown() function. The 7030 ** implementation of this method is expected to release all outstanding 7031 ** resources obtained by the mutex methods implementation, especially 7032 ** those obtained by the xMutexInit method. ^The xMutexEnd() 7033 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7034 ** 7035 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7036 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7037 ** xMutexNotheld) implement the following interfaces (respectively): 7038 ** 7039 ** <ul> 7040 ** <li> [sqlite3_mutex_alloc()] </li> 7041 ** <li> [sqlite3_mutex_free()] </li> 7042 ** <li> [sqlite3_mutex_enter()] </li> 7043 ** <li> [sqlite3_mutex_try()] </li> 7044 ** <li> [sqlite3_mutex_leave()] </li> 7045 ** <li> [sqlite3_mutex_held()] </li> 7046 ** <li> [sqlite3_mutex_notheld()] </li> 7047 ** </ul>)^ 7048 ** 7049 ** The only difference is that the public sqlite3_XXX functions enumerated 7050 ** above silently ignore any invocations that pass a NULL pointer instead 7051 ** of a valid mutex handle. The implementations of the methods defined 7052 ** by this structure are not required to handle this case, the results 7053 ** of passing a NULL pointer instead of a valid mutex handle are undefined 7054 ** (i.e. it is acceptable to provide an implementation that segfaults if 7055 ** it is passed a NULL pointer). 7056 ** 7057 ** The xMutexInit() method must be threadsafe. It must be harmless to 7058 ** invoke xMutexInit() multiple times within the same process and without 7059 ** intervening calls to xMutexEnd(). Second and subsequent calls to 7060 ** xMutexInit() must be no-ops. 7061 ** 7062 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7063 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7064 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7065 ** memory allocation for a fast or recursive mutex. 7066 ** 7067 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7068 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7069 ** If xMutexInit fails in any way, it is expected to clean up after itself 7070 ** prior to returning. 7071 */ 7072 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7073 struct sqlite3_mutex_methods { 7074 int (*xMutexInit)(void); 7075 int (*xMutexEnd)(void); 7076 sqlite3_mutex *(*xMutexAlloc)(int); 7077 void (*xMutexFree)(sqlite3_mutex *); 7078 void (*xMutexEnter)(sqlite3_mutex *); 7079 int (*xMutexTry)(sqlite3_mutex *); 7080 void (*xMutexLeave)(sqlite3_mutex *); 7081 int (*xMutexHeld)(sqlite3_mutex *); 7082 int (*xMutexNotheld)(sqlite3_mutex *); 7083 }; 7084 7085 /* 7086 ** CAPI3REF: Mutex Verification Routines 7087 ** 7088 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7089 ** are intended for use inside assert() statements. The SQLite core 7090 ** never uses these routines except inside an assert() and applications 7091 ** are advised to follow the lead of the core. The SQLite core only 7092 ** provides implementations for these routines when it is compiled 7093 ** with the SQLITE_DEBUG flag. External mutex implementations 7094 ** are only required to provide these routines if SQLITE_DEBUG is 7095 ** defined and if NDEBUG is not defined. 7096 ** 7097 ** These routines should return true if the mutex in their argument 7098 ** is held or not held, respectively, by the calling thread. 7099 ** 7100 ** The implementation is not required to provide versions of these 7101 ** routines that actually work. If the implementation does not provide working 7102 ** versions of these routines, it should at least provide stubs that always 7103 ** return true so that one does not get spurious assertion failures. 7104 ** 7105 ** If the argument to sqlite3_mutex_held() is a NULL pointer then 7106 ** the routine should return 1. This seems counter-intuitive since 7107 ** clearly the mutex cannot be held if it does not exist. But 7108 ** the reason the mutex does not exist is because the build is not 7109 ** using mutexes. And we do not want the assert() containing the 7110 ** call to sqlite3_mutex_held() to fail, so a non-zero return is 7111 ** the appropriate thing to do. The sqlite3_mutex_notheld() 7112 ** interface should also return 1 when given a NULL pointer. 7113 */ 7114 #ifndef NDEBUG 7115 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7116 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7117 #endif 7118 7119 /* 7120 ** CAPI3REF: Mutex Types 7121 ** 7122 ** The [sqlite3_mutex_alloc()] interface takes a single argument 7123 ** which is one of these integer constants. 7124 ** 7125 ** The set of static mutexes may change from one SQLite release to the 7126 ** next. Applications that override the built-in mutex logic must be 7127 ** prepared to accommodate additional static mutexes. 7128 */ 7129 #define SQLITE_MUTEX_FAST 0 7130 #define SQLITE_MUTEX_RECURSIVE 1 7131 #define SQLITE_MUTEX_STATIC_MASTER 2 7132 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7133 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7134 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7135 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7136 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7137 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7138 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7139 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7140 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7141 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7142 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7143 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7144 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7145 7146 /* 7147 ** CAPI3REF: Retrieve the mutex for a database connection 7148 ** METHOD: sqlite3 7149 ** 7150 ** ^This interface returns a pointer the [sqlite3_mutex] object that 7151 ** serializes access to the [database connection] given in the argument 7152 ** when the [threading mode] is Serialized. 7153 ** ^If the [threading mode] is Single-thread or Multi-thread then this 7154 ** routine returns a NULL pointer. 7155 */ 7156 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7157 7158 /* 7159 ** CAPI3REF: Low-Level Control Of Database Files 7160 ** METHOD: sqlite3 7161 ** KEYWORDS: {file control} 7162 ** 7163 ** ^The [sqlite3_file_control()] interface makes a direct call to the 7164 ** xFileControl method for the [sqlite3_io_methods] object associated 7165 ** with a particular database identified by the second argument. ^The 7166 ** name of the database is "main" for the main database or "temp" for the 7167 ** TEMP database, or the name that appears after the AS keyword for 7168 ** databases that are added using the [ATTACH] SQL command. 7169 ** ^A NULL pointer can be used in place of "main" to refer to the 7170 ** main database file. 7171 ** ^The third and fourth parameters to this routine 7172 ** are passed directly through to the second and third parameters of 7173 ** the xFileControl method. ^The return value of the xFileControl 7174 ** method becomes the return value of this routine. 7175 ** 7176 ** A few opcodes for [sqlite3_file_control()] are handled directly 7177 ** by the SQLite core and never invoke the 7178 ** sqlite3_io_methods.xFileControl method. 7179 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7180 ** a pointer to the underlying [sqlite3_file] object to be written into 7181 ** the space pointed to by the 4th parameter. The 7182 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7183 ** the [sqlite3_file] object associated with the journal file instead of 7184 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7185 ** a pointer to the underlying [sqlite3_vfs] object for the file. 7186 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7187 ** from the pager. 7188 ** 7189 ** ^If the second parameter (zDbName) does not match the name of any 7190 ** open database file, then SQLITE_ERROR is returned. ^This error 7191 ** code is not remembered and will not be recalled by [sqlite3_errcode()] 7192 ** or [sqlite3_errmsg()]. The underlying xFileControl method might 7193 ** also return SQLITE_ERROR. There is no way to distinguish between 7194 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7195 ** xFileControl method. 7196 ** 7197 ** See also: [file control opcodes] 7198 */ 7199 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7200 7201 /* 7202 ** CAPI3REF: Testing Interface 7203 ** 7204 ** ^The sqlite3_test_control() interface is used to read out internal 7205 ** state of SQLite and to inject faults into SQLite for testing 7206 ** purposes. ^The first parameter is an operation code that determines 7207 ** the number, meaning, and operation of all subsequent parameters. 7208 ** 7209 ** This interface is not for use by applications. It exists solely 7210 ** for verifying the correct operation of the SQLite library. Depending 7211 ** on how the SQLite library is compiled, this interface might not exist. 7212 ** 7213 ** The details of the operation codes, their meanings, the parameters 7214 ** they take, and what they do are all subject to change without notice. 7215 ** Unlike most of the SQLite API, this function is not guaranteed to 7216 ** operate consistently from one release to the next. 7217 */ 7218 SQLITE_API int sqlite3_test_control(int op, ...); 7219 7220 /* 7221 ** CAPI3REF: Testing Interface Operation Codes 7222 ** 7223 ** These constants are the valid operation code parameters used 7224 ** as the first argument to [sqlite3_test_control()]. 7225 ** 7226 ** These parameters and their meanings are subject to change 7227 ** without notice. These values are for testing purposes only. 7228 ** Applications should not use any of these parameters or the 7229 ** [sqlite3_test_control()] interface. 7230 */ 7231 #define SQLITE_TESTCTRL_FIRST 5 7232 #define SQLITE_TESTCTRL_PRNG_SAVE 5 7233 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 7234 #define SQLITE_TESTCTRL_PRNG_RESET 7 7235 #define SQLITE_TESTCTRL_BITVEC_TEST 8 7236 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 7237 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7238 #define SQLITE_TESTCTRL_PENDING_BYTE 11 7239 #define SQLITE_TESTCTRL_ASSERT 12 7240 #define SQLITE_TESTCTRL_ALWAYS 13 7241 #define SQLITE_TESTCTRL_RESERVE 14 7242 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7243 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7244 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7245 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7246 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7247 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7248 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7249 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7250 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7251 #define SQLITE_TESTCTRL_BYTEORDER 22 7252 #define SQLITE_TESTCTRL_ISINIT 23 7253 #define SQLITE_TESTCTRL_SORTER_MMAP 24 7254 #define SQLITE_TESTCTRL_IMPOSTER 25 7255 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7256 #define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7257 7258 /* 7259 ** CAPI3REF: SQL Keyword Checking 7260 ** 7261 ** These routines provide access to the set of SQL language keywords 7262 ** recognized by SQLite. Applications can uses these routines to determine 7263 ** whether or not a specific identifier needs to be escaped (for example, 7264 ** by enclosing in double-quotes) so as not to confuse the parser. 7265 ** 7266 ** The sqlite3_keyword_count() interface returns the number of distinct 7267 ** keywords understood by SQLite. 7268 ** 7269 ** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7270 ** makes *Z point to that keyword expressed as UTF8 and writes the number 7271 ** of bytes in the keyword into *L. The string that *Z points to is not 7272 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7273 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7274 ** or L are NULL or invalid pointers then calls to 7275 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7276 ** 7277 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7278 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7279 ** if it is and zero if not. 7280 ** 7281 ** The parser used by SQLite is forgiving. It is often possible to use 7282 ** a keyword as an identifier as long as such use does not result in a 7283 ** parsing ambiguity. For example, the statement 7284 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7285 ** creates a new table named "BEGIN" with three columns named 7286 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7287 ** using keywords as identifiers. Common techniques used to avoid keyword 7288 ** name collisions include: 7289 ** <ul> 7290 ** <li> Put all identifier names inside double-quotes. This is the official 7291 ** SQL way to escape identifier names. 7292 ** <li> Put identifier names inside [...]. This is not standard SQL, 7293 ** but it is what SQL Server does and so lots of programmers use this 7294 ** technique. 7295 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7296 ** with "Z". 7297 ** <li> Include a digit somewhere in every identifier name. 7298 ** </ul> 7299 ** 7300 ** Note that the number of keywords understood by SQLite can depend on 7301 ** compile-time options. For example, "VACUUM" is not a keyword if 7302 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7303 ** new keywords may be added to future releases of SQLite. 7304 */ 7305 SQLITE_API int sqlite3_keyword_count(void); 7306 SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 7307 SQLITE_API int sqlite3_keyword_check(const char*,int); 7308 7309 /* 7310 ** CAPI3REF: Dynamic String Object 7311 ** KEYWORDS: {dynamic string} 7312 ** 7313 ** An instance of the sqlite3_str object contains a dynamically-sized 7314 ** string under construction. 7315 ** 7316 ** The lifecycle of an sqlite3_str object is as follows: 7317 ** <ol> 7318 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7319 ** <li> ^Text is appended to the sqlite3_str object using various 7320 ** methods, such as [sqlite3_str_appendf()]. 7321 ** <li> ^The sqlite3_str object is destroyed and the string it created 7322 ** is returned using the [sqlite3_str_finish()] interface. 7323 ** </ol> 7324 */ 7325 typedef struct sqlite3_str sqlite3_str; 7326 7327 /* 7328 ** CAPI3REF: Create A New Dynamic String Object 7329 ** CONSTRUCTOR: sqlite3_str 7330 ** 7331 ** ^The [sqlite3_str_new(D)] interface allocates and initializes 7332 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7333 ** [sqlite3_str_new()] must be freed by a subsequent call to 7334 ** [sqlite3_str_finish(X)]. 7335 ** 7336 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7337 ** valid [sqlite3_str] object, though in the event of an out-of-memory 7338 ** error the returned object might be a special singleton that will 7339 ** silently reject new text, always return SQLITE_NOMEM from 7340 ** [sqlite3_str_errcode()], always return 0 for 7341 ** [sqlite3_str_length()], and always return NULL from 7342 ** [sqlite3_str_finish(X)]. It is always safe to use the value 7343 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7344 ** to any of the other [sqlite3_str] methods. 7345 ** 7346 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7347 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7348 ** length of the string contained in the [sqlite3_str] object will be 7349 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7350 ** of [SQLITE_MAX_LENGTH]. 7351 */ 7352 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 7353 7354 /* 7355 ** CAPI3REF: Finalize A Dynamic String 7356 ** DESTRUCTOR: sqlite3_str 7357 ** 7358 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7359 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7360 ** that contains the constructed string. The calling application should 7361 ** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7362 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7363 ** errors were encountered during construction of the string. ^The 7364 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7365 ** string in [sqlite3_str] object X is zero bytes long. 7366 */ 7367 SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 7368 7369 /* 7370 ** CAPI3REF: Add Content To A Dynamic String 7371 ** METHOD: sqlite3_str 7372 ** 7373 ** These interfaces add content to an sqlite3_str object previously obtained 7374 ** from [sqlite3_str_new()]. 7375 ** 7376 ** ^The [sqlite3_str_appendf(X,F,...)] and 7377 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7378 ** functionality of SQLite to append formatted text onto the end of 7379 ** [sqlite3_str] object X. 7380 ** 7381 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7382 ** onto the end of the [sqlite3_str] object X. N must be non-negative. 7383 ** S must contain at least N non-zero bytes of content. To append a 7384 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7385 ** method instead. 7386 ** 7387 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7388 ** zero-terminated string S onto the end of [sqlite3_str] object X. 7389 ** 7390 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7391 ** single-byte character C onto the end of [sqlite3_str] object X. 7392 ** ^This method can be used, for example, to add whitespace indentation. 7393 ** 7394 ** ^The [sqlite3_str_reset(X)] method resets the string under construction 7395 ** inside [sqlite3_str] object X back to zero bytes in length. 7396 ** 7397 ** These methods do not return a result code. ^If an error occurs, that fact 7398 ** is recorded in the [sqlite3_str] object and can be recovered by a 7399 ** subsequent call to [sqlite3_str_errcode(X)]. 7400 */ 7401 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7402 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7403 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7404 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7405 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7406 SQLITE_API void sqlite3_str_reset(sqlite3_str*); 7407 7408 /* 7409 ** CAPI3REF: Status Of A Dynamic String 7410 ** METHOD: sqlite3_str 7411 ** 7412 ** These interfaces return the current status of an [sqlite3_str] object. 7413 ** 7414 ** ^If any prior errors have occurred while constructing the dynamic string 7415 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7416 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7417 ** [SQLITE_NOMEM] following any out-of-memory error, or 7418 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7419 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7420 ** 7421 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7422 ** of the dynamic string under construction in [sqlite3_str] object X. 7423 ** ^The length returned by [sqlite3_str_length(X)] does not include the 7424 ** zero-termination byte. 7425 ** 7426 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7427 ** content of the dynamic string under construction in X. The value 7428 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7429 ** and might be freed or altered by any subsequent method on the same 7430 ** [sqlite3_str] object. Applications must not used the pointer returned 7431 ** [sqlite3_str_value(X)] after any subsequent method call on the same 7432 ** object. ^Applications may change the content of the string returned 7433 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7434 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7435 ** write any byte after any subsequent sqlite3_str method call. 7436 */ 7437 SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 7438 SQLITE_API int sqlite3_str_length(sqlite3_str*); 7439 SQLITE_API char *sqlite3_str_value(sqlite3_str*); 7440 7441 /* 7442 ** CAPI3REF: SQLite Runtime Status 7443 ** 7444 ** ^These interfaces are used to retrieve runtime status information 7445 ** about the performance of SQLite, and optionally to reset various 7446 ** highwater marks. ^The first argument is an integer code for 7447 ** the specific parameter to measure. ^(Recognized integer codes 7448 ** are of the form [status parameters | SQLITE_STATUS_...].)^ 7449 ** ^The current value of the parameter is returned into *pCurrent. 7450 ** ^The highest recorded value is returned in *pHighwater. ^If the 7451 ** resetFlag is true, then the highest record value is reset after 7452 ** *pHighwater is written. ^(Some parameters do not record the highest 7453 ** value. For those parameters 7454 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7455 ** ^(Other parameters record only the highwater mark and not the current 7456 ** value. For these latter parameters nothing is written into *pCurrent.)^ 7457 ** 7458 ** ^The sqlite3_status() and sqlite3_status64() routines return 7459 ** SQLITE_OK on success and a non-zero [error code] on failure. 7460 ** 7461 ** If either the current value or the highwater mark is too large to 7462 ** be represented by a 32-bit integer, then the values returned by 7463 ** sqlite3_status() are undefined. 7464 ** 7465 ** See also: [sqlite3_db_status()] 7466 */ 7467 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7468 SQLITE_API int sqlite3_status64( 7469 int op, 7470 sqlite3_int64 *pCurrent, 7471 sqlite3_int64 *pHighwater, 7472 int resetFlag 7473 ); 7474 7475 7476 /* 7477 ** CAPI3REF: Status Parameters 7478 ** KEYWORDS: {status parameters} 7479 ** 7480 ** These integer constants designate various run-time status parameters 7481 ** that can be returned by [sqlite3_status()]. 7482 ** 7483 ** <dl> 7484 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7485 ** <dd>This parameter is the current amount of memory checked out 7486 ** using [sqlite3_malloc()], either directly or indirectly. The 7487 ** figure includes calls made to [sqlite3_malloc()] by the application 7488 ** and internal memory usage by the SQLite library. Auxiliary page-cache 7489 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7490 ** this parameter. The amount returned is the sum of the allocation 7491 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7492 ** 7493 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7494 ** <dd>This parameter records the largest memory allocation request 7495 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7496 ** internal equivalents). Only the value returned in the 7497 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7498 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7499 ** 7500 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7501 ** <dd>This parameter records the number of separate memory allocations 7502 ** currently checked out.</dd>)^ 7503 ** 7504 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7505 ** <dd>This parameter returns the number of pages used out of the 7506 ** [pagecache memory allocator] that was configured using 7507 ** [SQLITE_CONFIG_PAGECACHE]. The 7508 ** value returned is in pages, not in bytes.</dd>)^ 7509 ** 7510 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7511 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7512 ** <dd>This parameter returns the number of bytes of page cache 7513 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7514 ** buffer and where forced to overflow to [sqlite3_malloc()]. The 7515 ** returned value includes allocations that overflowed because they 7516 ** where too large (they were larger than the "sz" parameter to 7517 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7518 ** no space was left in the page cache.</dd>)^ 7519 ** 7520 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7521 ** <dd>This parameter records the largest memory allocation request 7522 ** handed to [pagecache memory allocator]. Only the value returned in the 7523 ** *pHighwater parameter to [sqlite3_status()] is of interest. 7524 ** The value written into the *pCurrent parameter is undefined.</dd>)^ 7525 ** 7526 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7527 ** <dd>No longer used.</dd> 7528 ** 7529 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7530 ** <dd>No longer used.</dd> 7531 ** 7532 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7533 ** <dd>No longer used.</dd> 7534 ** 7535 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7536 ** <dd>The *pHighwater parameter records the deepest parser stack. 7537 ** The *pCurrent value is undefined. The *pHighwater value is only 7538 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7539 ** </dl> 7540 ** 7541 ** New status parameters may be added from time to time. 7542 */ 7543 #define SQLITE_STATUS_MEMORY_USED 0 7544 #define SQLITE_STATUS_PAGECACHE_USED 1 7545 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7546 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7547 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7548 #define SQLITE_STATUS_MALLOC_SIZE 5 7549 #define SQLITE_STATUS_PARSER_STACK 6 7550 #define SQLITE_STATUS_PAGECACHE_SIZE 7 7551 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7552 #define SQLITE_STATUS_MALLOC_COUNT 9 7553 7554 /* 7555 ** CAPI3REF: Database Connection Status 7556 ** METHOD: sqlite3 7557 ** 7558 ** ^This interface is used to retrieve runtime status information 7559 ** about a single [database connection]. ^The first argument is the 7560 ** database connection object to be interrogated. ^The second argument 7561 ** is an integer constant, taken from the set of 7562 ** [SQLITE_DBSTATUS options], that 7563 ** determines the parameter to interrogate. The set of 7564 ** [SQLITE_DBSTATUS options] is likely 7565 ** to grow in future releases of SQLite. 7566 ** 7567 ** ^The current value of the requested parameter is written into *pCur 7568 ** and the highest instantaneous value is written into *pHiwtr. ^If 7569 ** the resetFlg is true, then the highest instantaneous value is 7570 ** reset back down to the current value. 7571 ** 7572 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7573 ** non-zero [error code] on failure. 7574 ** 7575 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7576 */ 7577 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7578 7579 /* 7580 ** CAPI3REF: Status Parameters for database connections 7581 ** KEYWORDS: {SQLITE_DBSTATUS options} 7582 ** 7583 ** These constants are the available integer "verbs" that can be passed as 7584 ** the second argument to the [sqlite3_db_status()] interface. 7585 ** 7586 ** New verbs may be added in future releases of SQLite. Existing verbs 7587 ** might be discontinued. Applications should check the return code from 7588 ** [sqlite3_db_status()] to make sure that the call worked. 7589 ** The [sqlite3_db_status()] interface will return a non-zero error code 7590 ** if a discontinued or unsupported verb is invoked. 7591 ** 7592 ** <dl> 7593 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7594 ** <dd>This parameter returns the number of lookaside memory slots currently 7595 ** checked out.</dd>)^ 7596 ** 7597 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7598 ** <dd>This parameter returns the number malloc attempts that were 7599 ** satisfied using lookaside memory. Only the high-water value is meaningful; 7600 ** the current value is always zero.)^ 7601 ** 7602 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7603 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7604 ** <dd>This parameter returns the number malloc attempts that might have 7605 ** been satisfied using lookaside memory but failed due to the amount of 7606 ** memory requested being larger than the lookaside slot size. 7607 ** Only the high-water value is meaningful; 7608 ** the current value is always zero.)^ 7609 ** 7610 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7611 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7612 ** <dd>This parameter returns the number malloc attempts that might have 7613 ** been satisfied using lookaside memory but failed due to all lookaside 7614 ** memory already being in use. 7615 ** Only the high-water value is meaningful; 7616 ** the current value is always zero.)^ 7617 ** 7618 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7619 ** <dd>This parameter returns the approximate number of bytes of heap 7620 ** memory used by all pager caches associated with the database connection.)^ 7621 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7622 ** 7623 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7624 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7625 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7626 ** pager cache is shared between two or more connections the bytes of heap 7627 ** memory used by that pager cache is divided evenly between the attached 7628 ** connections.)^ In other words, if none of the pager caches associated 7629 ** with the database connection are shared, this request returns the same 7630 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7631 ** shared, the value returned by this call will be smaller than that returned 7632 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7633 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7634 ** 7635 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7636 ** <dd>This parameter returns the approximate number of bytes of heap 7637 ** memory used to store the schema for all databases associated 7638 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7639 ** ^The full amount of memory used by the schemas is reported, even if the 7640 ** schema memory is shared with other database connections due to 7641 ** [shared cache mode] being enabled. 7642 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7643 ** 7644 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7645 ** <dd>This parameter returns the approximate number of bytes of heap 7646 ** and lookaside memory used by all prepared statements associated with 7647 ** the database connection.)^ 7648 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7649 ** </dd> 7650 ** 7651 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7652 ** <dd>This parameter returns the number of pager cache hits that have 7653 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7654 ** is always 0. 7655 ** </dd> 7656 ** 7657 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7658 ** <dd>This parameter returns the number of pager cache misses that have 7659 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7660 ** is always 0. 7661 ** </dd> 7662 ** 7663 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7664 ** <dd>This parameter returns the number of dirty cache entries that have 7665 ** been written to disk. Specifically, the number of pages written to the 7666 ** wal file in wal mode databases, or the number of pages written to the 7667 ** database file in rollback mode databases. Any pages written as part of 7668 ** transaction rollback or database recovery operations are not included. 7669 ** If an IO or other error occurs while writing a page to disk, the effect 7670 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7671 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7672 ** </dd> 7673 ** 7674 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7675 ** <dd>This parameter returns the number of dirty cache entries that have 7676 ** been written to disk in the middle of a transaction due to the page 7677 ** cache overflowing. Transactions are more efficient if they are written 7678 ** to disk all at once. When pages spill mid-transaction, that introduces 7679 ** additional overhead. This parameter can be used help identify 7680 ** inefficiencies that can be resolve by increasing the cache size. 7681 ** </dd> 7682 ** 7683 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7684 ** <dd>This parameter returns zero for the current value if and only if 7685 ** all foreign key constraints (deferred or immediate) have been 7686 ** resolved.)^ ^The highwater mark is always 0. 7687 ** </dd> 7688 ** </dl> 7689 */ 7690 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7691 #define SQLITE_DBSTATUS_CACHE_USED 1 7692 #define SQLITE_DBSTATUS_SCHEMA_USED 2 7693 #define SQLITE_DBSTATUS_STMT_USED 3 7694 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7695 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7696 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7697 #define SQLITE_DBSTATUS_CACHE_HIT 7 7698 #define SQLITE_DBSTATUS_CACHE_MISS 8 7699 #define SQLITE_DBSTATUS_CACHE_WRITE 9 7700 #define SQLITE_DBSTATUS_DEFERRED_FKS 10 7701 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7702 #define SQLITE_DBSTATUS_CACHE_SPILL 12 7703 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7704 7705 7706 /* 7707 ** CAPI3REF: Prepared Statement Status 7708 ** METHOD: sqlite3_stmt 7709 ** 7710 ** ^(Each prepared statement maintains various 7711 ** [SQLITE_STMTSTATUS counters] that measure the number 7712 ** of times it has performed specific operations.)^ These counters can 7713 ** be used to monitor the performance characteristics of the prepared 7714 ** statements. For example, if the number of table steps greatly exceeds 7715 ** the number of table searches or result rows, that would tend to indicate 7716 ** that the prepared statement is using a full table scan rather than 7717 ** an index. 7718 ** 7719 ** ^(This interface is used to retrieve and reset counter values from 7720 ** a [prepared statement]. The first argument is the prepared statement 7721 ** object to be interrogated. The second argument 7722 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7723 ** to be interrogated.)^ 7724 ** ^The current value of the requested counter is returned. 7725 ** ^If the resetFlg is true, then the counter is reset to zero after this 7726 ** interface call returns. 7727 ** 7728 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7729 */ 7730 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7731 7732 /* 7733 ** CAPI3REF: Status Parameters for prepared statements 7734 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7735 ** 7736 ** These preprocessor macros define integer codes that name counter 7737 ** values associated with the [sqlite3_stmt_status()] interface. 7738 ** The meanings of the various counters are as follows: 7739 ** 7740 ** <dl> 7741 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7742 ** <dd>^This is the number of times that SQLite has stepped forward in 7743 ** a table as part of a full table scan. Large numbers for this counter 7744 ** may indicate opportunities for performance improvement through 7745 ** careful use of indices.</dd> 7746 ** 7747 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7748 ** <dd>^This is the number of sort operations that have occurred. 7749 ** A non-zero value in this counter may indicate an opportunity to 7750 ** improvement performance through careful use of indices.</dd> 7751 ** 7752 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7753 ** <dd>^This is the number of rows inserted into transient indices that 7754 ** were created automatically in order to help joins run faster. 7755 ** A non-zero value in this counter may indicate an opportunity to 7756 ** improvement performance by adding permanent indices that do not 7757 ** need to be reinitialized each time the statement is run.</dd> 7758 ** 7759 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7760 ** <dd>^This is the number of virtual machine operations executed 7761 ** by the prepared statement if that number is less than or equal 7762 ** to 2147483647. The number of virtual machine operations can be 7763 ** used as a proxy for the total work done by the prepared statement. 7764 ** If the number of virtual machine operations exceeds 2147483647 7765 ** then the value returned by this statement status code is undefined. 7766 ** 7767 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7768 ** <dd>^This is the number of times that the prepare statement has been 7769 ** automatically regenerated due to schema changes or change to 7770 ** [bound parameters] that might affect the query plan. 7771 ** 7772 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7773 ** <dd>^This is the number of times that the prepared statement has 7774 ** been run. A single "run" for the purposes of this counter is one 7775 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7776 ** The counter is incremented on the first [sqlite3_step()] call of each 7777 ** cycle. 7778 ** 7779 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7780 ** <dd>^This is the approximate number of bytes of heap memory 7781 ** used to store the prepared statement. ^This value is not actually 7782 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7783 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7784 ** </dd> 7785 ** </dl> 7786 */ 7787 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7788 #define SQLITE_STMTSTATUS_SORT 2 7789 #define SQLITE_STMTSTATUS_AUTOINDEX 3 7790 #define SQLITE_STMTSTATUS_VM_STEP 4 7791 #define SQLITE_STMTSTATUS_REPREPARE 5 7792 #define SQLITE_STMTSTATUS_RUN 6 7793 #define SQLITE_STMTSTATUS_MEMUSED 99 7794 7795 /* 7796 ** CAPI3REF: Custom Page Cache Object 7797 ** 7798 ** The sqlite3_pcache type is opaque. It is implemented by 7799 ** the pluggable module. The SQLite core has no knowledge of 7800 ** its size or internal structure and never deals with the 7801 ** sqlite3_pcache object except by holding and passing pointers 7802 ** to the object. 7803 ** 7804 ** See [sqlite3_pcache_methods2] for additional information. 7805 */ 7806 typedef struct sqlite3_pcache sqlite3_pcache; 7807 7808 /* 7809 ** CAPI3REF: Custom Page Cache Object 7810 ** 7811 ** The sqlite3_pcache_page object represents a single page in the 7812 ** page cache. The page cache will allocate instances of this 7813 ** object. Various methods of the page cache use pointers to instances 7814 ** of this object as parameters or as their return value. 7815 ** 7816 ** See [sqlite3_pcache_methods2] for additional information. 7817 */ 7818 typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7819 struct sqlite3_pcache_page { 7820 void *pBuf; /* The content of the page */ 7821 void *pExtra; /* Extra information associated with the page */ 7822 }; 7823 7824 /* 7825 ** CAPI3REF: Application Defined Page Cache. 7826 ** KEYWORDS: {page cache} 7827 ** 7828 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7829 ** register an alternative page cache implementation by passing in an 7830 ** instance of the sqlite3_pcache_methods2 structure.)^ 7831 ** In many applications, most of the heap memory allocated by 7832 ** SQLite is used for the page cache. 7833 ** By implementing a 7834 ** custom page cache using this API, an application can better control 7835 ** the amount of memory consumed by SQLite, the way in which 7836 ** that memory is allocated and released, and the policies used to 7837 ** determine exactly which parts of a database file are cached and for 7838 ** how long. 7839 ** 7840 ** The alternative page cache mechanism is an 7841 ** extreme measure that is only needed by the most demanding applications. 7842 ** The built-in page cache is recommended for most uses. 7843 ** 7844 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7845 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7846 ** the application may discard the parameter after the call to 7847 ** [sqlite3_config()] returns.)^ 7848 ** 7849 ** [[the xInit() page cache method]] 7850 ** ^(The xInit() method is called once for each effective 7851 ** call to [sqlite3_initialize()])^ 7852 ** (usually only once during the lifetime of the process). ^(The xInit() 7853 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7854 ** The intent of the xInit() method is to set up global data structures 7855 ** required by the custom page cache implementation. 7856 ** ^(If the xInit() method is NULL, then the 7857 ** built-in default page cache is used instead of the application defined 7858 ** page cache.)^ 7859 ** 7860 ** [[the xShutdown() page cache method]] 7861 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7862 ** It can be used to clean up 7863 ** any outstanding resources before process shutdown, if required. 7864 ** ^The xShutdown() method may be NULL. 7865 ** 7866 ** ^SQLite automatically serializes calls to the xInit method, 7867 ** so the xInit method need not be threadsafe. ^The 7868 ** xShutdown method is only called from [sqlite3_shutdown()] so it does 7869 ** not need to be threadsafe either. All other methods must be threadsafe 7870 ** in multithreaded applications. 7871 ** 7872 ** ^SQLite will never invoke xInit() more than once without an intervening 7873 ** call to xShutdown(). 7874 ** 7875 ** [[the xCreate() page cache methods]] 7876 ** ^SQLite invokes the xCreate() method to construct a new cache instance. 7877 ** SQLite will typically create one cache instance for each open database file, 7878 ** though this is not guaranteed. ^The 7879 ** first parameter, szPage, is the size in bytes of the pages that must 7880 ** be allocated by the cache. ^szPage will always a power of two. ^The 7881 ** second parameter szExtra is a number of bytes of extra storage 7882 ** associated with each page cache entry. ^The szExtra parameter will 7883 ** a number less than 250. SQLite will use the 7884 ** extra szExtra bytes on each page to store metadata about the underlying 7885 ** database page on disk. The value passed into szExtra depends 7886 ** on the SQLite version, the target platform, and how SQLite was compiled. 7887 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7888 ** created will be used to cache database pages of a file stored on disk, or 7889 ** false if it is used for an in-memory database. The cache implementation 7890 ** does not have to do anything special based with the value of bPurgeable; 7891 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7892 ** never invoke xUnpin() except to deliberately delete a page. 7893 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7894 ** false will always have the "discard" flag set to true. 7895 ** ^Hence, a cache created with bPurgeable false will 7896 ** never contain any unpinned pages. 7897 ** 7898 ** [[the xCachesize() page cache method]] 7899 ** ^(The xCachesize() method may be called at any time by SQLite to set the 7900 ** suggested maximum cache-size (number of pages stored by) the cache 7901 ** instance passed as the first argument. This is the value configured using 7902 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7903 ** parameter, the implementation is not required to do anything with this 7904 ** value; it is advisory only. 7905 ** 7906 ** [[the xPagecount() page cache methods]] 7907 ** The xPagecount() method must return the number of pages currently 7908 ** stored in the cache, both pinned and unpinned. 7909 ** 7910 ** [[the xFetch() page cache methods]] 7911 ** The xFetch() method locates a page in the cache and returns a pointer to 7912 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7913 ** The pBuf element of the returned sqlite3_pcache_page object will be a 7914 ** pointer to a buffer of szPage bytes used to store the content of a 7915 ** single database page. The pExtra element of sqlite3_pcache_page will be 7916 ** a pointer to the szExtra bytes of extra storage that SQLite has requested 7917 ** for each entry in the page cache. 7918 ** 7919 ** The page to be fetched is determined by the key. ^The minimum key value 7920 ** is 1. After it has been retrieved using xFetch, the page is considered 7921 ** to be "pinned". 7922 ** 7923 ** If the requested page is already in the page cache, then the page cache 7924 ** implementation must return a pointer to the page buffer with its content 7925 ** intact. If the requested page is not already in the cache, then the 7926 ** cache implementation should use the value of the createFlag 7927 ** parameter to help it determined what action to take: 7928 ** 7929 ** <table border=1 width=85% align=center> 7930 ** <tr><th> createFlag <th> Behavior when page is not already in cache 7931 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7932 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7933 ** Otherwise return NULL. 7934 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7935 ** NULL if allocating a new page is effectively impossible. 7936 ** </table> 7937 ** 7938 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7939 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 7940 ** failed.)^ In between the to xFetch() calls, SQLite may 7941 ** attempt to unpin one or more cache pages by spilling the content of 7942 ** pinned pages to disk and synching the operating system disk cache. 7943 ** 7944 ** [[the xUnpin() page cache method]] 7945 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7946 ** as its second argument. If the third parameter, discard, is non-zero, 7947 ** then the page must be evicted from the cache. 7948 ** ^If the discard parameter is 7949 ** zero, then the page may be discarded or retained at the discretion of 7950 ** page cache implementation. ^The page cache implementation 7951 ** may choose to evict unpinned pages at any time. 7952 ** 7953 ** The cache must not perform any reference counting. A single 7954 ** call to xUnpin() unpins the page regardless of the number of prior calls 7955 ** to xFetch(). 7956 ** 7957 ** [[the xRekey() page cache methods]] 7958 ** The xRekey() method is used to change the key value associated with the 7959 ** page passed as the second argument. If the cache 7960 ** previously contains an entry associated with newKey, it must be 7961 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7962 ** to be pinned. 7963 ** 7964 ** When SQLite calls the xTruncate() method, the cache must discard all 7965 ** existing cache entries with page numbers (keys) greater than or equal 7966 ** to the value of the iLimit parameter passed to xTruncate(). If any 7967 ** of these pages are pinned, they are implicitly unpinned, meaning that 7968 ** they can be safely discarded. 7969 ** 7970 ** [[the xDestroy() page cache method]] 7971 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7972 ** All resources associated with the specified cache should be freed. ^After 7973 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7974 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7975 ** functions. 7976 ** 7977 ** [[the xShrink() page cache method]] 7978 ** ^SQLite invokes the xShrink() method when it wants the page cache to 7979 ** free up as much of heap memory as possible. The page cache implementation 7980 ** is not obligated to free any memory, but well-behaved implementations should 7981 ** do their best. 7982 */ 7983 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7984 struct sqlite3_pcache_methods2 { 7985 int iVersion; 7986 void *pArg; 7987 int (*xInit)(void*); 7988 void (*xShutdown)(void*); 7989 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7990 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7991 int (*xPagecount)(sqlite3_pcache*); 7992 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7993 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7994 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7995 unsigned oldKey, unsigned newKey); 7996 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7997 void (*xDestroy)(sqlite3_pcache*); 7998 void (*xShrink)(sqlite3_pcache*); 7999 }; 8000 8001 /* 8002 ** This is the obsolete pcache_methods object that has now been replaced 8003 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8004 ** retained in the header file for backwards compatibility only. 8005 */ 8006 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8007 struct sqlite3_pcache_methods { 8008 void *pArg; 8009 int (*xInit)(void*); 8010 void (*xShutdown)(void*); 8011 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8012 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8013 int (*xPagecount)(sqlite3_pcache*); 8014 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8015 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8016 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8017 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8018 void (*xDestroy)(sqlite3_pcache*); 8019 }; 8020 8021 8022 /* 8023 ** CAPI3REF: Online Backup Object 8024 ** 8025 ** The sqlite3_backup object records state information about an ongoing 8026 ** online backup operation. ^The sqlite3_backup object is created by 8027 ** a call to [sqlite3_backup_init()] and is destroyed by a call to 8028 ** [sqlite3_backup_finish()]. 8029 ** 8030 ** See Also: [Using the SQLite Online Backup API] 8031 */ 8032 typedef struct sqlite3_backup sqlite3_backup; 8033 8034 /* 8035 ** CAPI3REF: Online Backup API. 8036 ** 8037 ** The backup API copies the content of one database into another. 8038 ** It is useful either for creating backups of databases or 8039 ** for copying in-memory databases to or from persistent files. 8040 ** 8041 ** See Also: [Using the SQLite Online Backup API] 8042 ** 8043 ** ^SQLite holds a write transaction open on the destination database file 8044 ** for the duration of the backup operation. 8045 ** ^The source database is read-locked only while it is being read; 8046 ** it is not locked continuously for the entire backup operation. 8047 ** ^Thus, the backup may be performed on a live source database without 8048 ** preventing other database connections from 8049 ** reading or writing to the source database while the backup is underway. 8050 ** 8051 ** ^(To perform a backup operation: 8052 ** <ol> 8053 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8054 ** backup, 8055 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8056 ** the data between the two databases, and finally 8057 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8058 ** associated with the backup operation. 8059 ** </ol>)^ 8060 ** There should be exactly one call to sqlite3_backup_finish() for each 8061 ** successful call to sqlite3_backup_init(). 8062 ** 8063 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8064 ** 8065 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8066 ** [database connection] associated with the destination database 8067 ** and the database name, respectively. 8068 ** ^The database name is "main" for the main database, "temp" for the 8069 ** temporary database, or the name specified after the AS keyword in 8070 ** an [ATTACH] statement for an attached database. 8071 ** ^The S and M arguments passed to 8072 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8073 ** and database name of the source database, respectively. 8074 ** ^The source and destination [database connections] (parameters S and D) 8075 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8076 ** an error. 8077 ** 8078 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8079 ** there is already a read or read-write transaction open on the 8080 ** destination database. 8081 ** 8082 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8083 ** returned and an error code and error message are stored in the 8084 ** destination [database connection] D. 8085 ** ^The error code and message for the failed call to sqlite3_backup_init() 8086 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8087 ** [sqlite3_errmsg16()] functions. 8088 ** ^A successful call to sqlite3_backup_init() returns a pointer to an 8089 ** [sqlite3_backup] object. 8090 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8091 ** sqlite3_backup_finish() functions to perform the specified backup 8092 ** operation. 8093 ** 8094 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8095 ** 8096 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8097 ** the source and destination databases specified by [sqlite3_backup] object B. 8098 ** ^If N is negative, all remaining source pages are copied. 8099 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8100 ** are still more pages to be copied, then the function returns [SQLITE_OK]. 8101 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8102 ** from source to destination, then it returns [SQLITE_DONE]. 8103 ** ^If an error occurs while running sqlite3_backup_step(B,N), 8104 ** then an [error code] is returned. ^As well as [SQLITE_OK] and 8105 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8106 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8107 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8108 ** 8109 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8110 ** <ol> 8111 ** <li> the destination database was opened read-only, or 8112 ** <li> the destination database is using write-ahead-log journaling 8113 ** and the destination and source page sizes differ, or 8114 ** <li> the destination database is an in-memory database and the 8115 ** destination and source page sizes differ. 8116 ** </ol>)^ 8117 ** 8118 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8119 ** the [sqlite3_busy_handler | busy-handler function] 8120 ** is invoked (if one is specified). ^If the 8121 ** busy-handler returns non-zero before the lock is available, then 8122 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8123 ** sqlite3_backup_step() can be retried later. ^If the source 8124 ** [database connection] 8125 ** is being used to write to the source database when sqlite3_backup_step() 8126 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8127 ** case the call to sqlite3_backup_step() can be retried later on. ^(If 8128 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8129 ** [SQLITE_READONLY] is returned, then 8130 ** there is no point in retrying the call to sqlite3_backup_step(). These 8131 ** errors are considered fatal.)^ The application must accept 8132 ** that the backup operation has failed and pass the backup operation handle 8133 ** to the sqlite3_backup_finish() to release associated resources. 8134 ** 8135 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8136 ** on the destination file. ^The exclusive lock is not released until either 8137 ** sqlite3_backup_finish() is called or the backup operation is complete 8138 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8139 ** sqlite3_backup_step() obtains a [shared lock] on the source database that 8140 ** lasts for the duration of the sqlite3_backup_step() call. 8141 ** ^Because the source database is not locked between calls to 8142 ** sqlite3_backup_step(), the source database may be modified mid-way 8143 ** through the backup process. ^If the source database is modified by an 8144 ** external process or via a database connection other than the one being 8145 ** used by the backup operation, then the backup will be automatically 8146 ** restarted by the next call to sqlite3_backup_step(). ^If the source 8147 ** database is modified by the using the same database connection as is used 8148 ** by the backup operation, then the backup database is automatically 8149 ** updated at the same time. 8150 ** 8151 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8152 ** 8153 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8154 ** application wishes to abandon the backup operation, the application 8155 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8156 ** ^The sqlite3_backup_finish() interfaces releases all 8157 ** resources associated with the [sqlite3_backup] object. 8158 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8159 ** active write-transaction on the destination database is rolled back. 8160 ** The [sqlite3_backup] object is invalid 8161 ** and may not be used following a call to sqlite3_backup_finish(). 8162 ** 8163 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8164 ** sqlite3_backup_step() errors occurred, regardless or whether or not 8165 ** sqlite3_backup_step() completed. 8166 ** ^If an out-of-memory condition or IO error occurred during any prior 8167 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8168 ** sqlite3_backup_finish() returns the corresponding [error code]. 8169 ** 8170 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8171 ** is not a permanent error and does not affect the return value of 8172 ** sqlite3_backup_finish(). 8173 ** 8174 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8175 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8176 ** 8177 ** ^The sqlite3_backup_remaining() routine returns the number of pages still 8178 ** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8179 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8180 ** in the source database at the conclusion of the most recent 8181 ** sqlite3_backup_step(). 8182 ** ^(The values returned by these functions are only updated by 8183 ** sqlite3_backup_step(). If the source database is modified in a way that 8184 ** changes the size of the source database or the number of pages remaining, 8185 ** those changes are not reflected in the output of sqlite3_backup_pagecount() 8186 ** and sqlite3_backup_remaining() until after the next 8187 ** sqlite3_backup_step().)^ 8188 ** 8189 ** <b>Concurrent Usage of Database Handles</b> 8190 ** 8191 ** ^The source [database connection] may be used by the application for other 8192 ** purposes while a backup operation is underway or being initialized. 8193 ** ^If SQLite is compiled and configured to support threadsafe database 8194 ** connections, then the source database connection may be used concurrently 8195 ** from within other threads. 8196 ** 8197 ** However, the application must guarantee that the destination 8198 ** [database connection] is not passed to any other API (by any thread) after 8199 ** sqlite3_backup_init() is called and before the corresponding call to 8200 ** sqlite3_backup_finish(). SQLite does not currently check to see 8201 ** if the application incorrectly accesses the destination [database connection] 8202 ** and so no error code is reported, but the operations may malfunction 8203 ** nevertheless. Use of the destination database connection while a 8204 ** backup is in progress might also also cause a mutex deadlock. 8205 ** 8206 ** If running in [shared cache mode], the application must 8207 ** guarantee that the shared cache used by the destination database 8208 ** is not accessed while the backup is running. In practice this means 8209 ** that the application must guarantee that the disk file being 8210 ** backed up to is not accessed by any connection within the process, 8211 ** not just the specific connection that was passed to sqlite3_backup_init(). 8212 ** 8213 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8214 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8215 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8216 ** APIs are not strictly speaking threadsafe. If they are invoked at the 8217 ** same time as another thread is invoking sqlite3_backup_step() it is 8218 ** possible that they return invalid values. 8219 */ 8220 SQLITE_API sqlite3_backup *sqlite3_backup_init( 8221 sqlite3 *pDest, /* Destination database handle */ 8222 const char *zDestName, /* Destination database name */ 8223 sqlite3 *pSource, /* Source database handle */ 8224 const char *zSourceName /* Source database name */ 8225 ); 8226 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8227 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 8228 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 8229 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 8230 8231 /* 8232 ** CAPI3REF: Unlock Notification 8233 ** METHOD: sqlite3 8234 ** 8235 ** ^When running in shared-cache mode, a database operation may fail with 8236 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8237 ** individual tables within the shared-cache cannot be obtained. See 8238 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8239 ** ^This API may be used to register a callback that SQLite will invoke 8240 ** when the connection currently holding the required lock relinquishes it. 8241 ** ^This API is only available if the library was compiled with the 8242 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8243 ** 8244 ** See Also: [Using the SQLite Unlock Notification Feature]. 8245 ** 8246 ** ^Shared-cache locks are released when a database connection concludes 8247 ** its current transaction, either by committing it or rolling it back. 8248 ** 8249 ** ^When a connection (known as the blocked connection) fails to obtain a 8250 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8251 ** identity of the database connection (the blocking connection) that 8252 ** has locked the required resource is stored internally. ^After an 8253 ** application receives an SQLITE_LOCKED error, it may call the 8254 ** sqlite3_unlock_notify() method with the blocked connection handle as 8255 ** the first argument to register for a callback that will be invoked 8256 ** when the blocking connections current transaction is concluded. ^The 8257 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8258 ** call that concludes the blocking connections transaction. 8259 ** 8260 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8261 ** there is a chance that the blocking connection will have already 8262 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8263 ** If this happens, then the specified callback is invoked immediately, 8264 ** from within the call to sqlite3_unlock_notify().)^ 8265 ** 8266 ** ^If the blocked connection is attempting to obtain a write-lock on a 8267 ** shared-cache table, and more than one other connection currently holds 8268 ** a read-lock on the same table, then SQLite arbitrarily selects one of 8269 ** the other connections to use as the blocking connection. 8270 ** 8271 ** ^(There may be at most one unlock-notify callback registered by a 8272 ** blocked connection. If sqlite3_unlock_notify() is called when the 8273 ** blocked connection already has a registered unlock-notify callback, 8274 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8275 ** called with a NULL pointer as its second argument, then any existing 8276 ** unlock-notify callback is canceled. ^The blocked connections 8277 ** unlock-notify callback may also be canceled by closing the blocked 8278 ** connection using [sqlite3_close()]. 8279 ** 8280 ** The unlock-notify callback is not reentrant. If an application invokes 8281 ** any sqlite3_xxx API functions from within an unlock-notify callback, a 8282 ** crash or deadlock may be the result. 8283 ** 8284 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8285 ** returns SQLITE_OK. 8286 ** 8287 ** <b>Callback Invocation Details</b> 8288 ** 8289 ** When an unlock-notify callback is registered, the application provides a 8290 ** single void* pointer that is passed to the callback when it is invoked. 8291 ** However, the signature of the callback function allows SQLite to pass 8292 ** it an array of void* context pointers. The first argument passed to 8293 ** an unlock-notify callback is a pointer to an array of void* pointers, 8294 ** and the second is the number of entries in the array. 8295 ** 8296 ** When a blocking connections transaction is concluded, there may be 8297 ** more than one blocked connection that has registered for an unlock-notify 8298 ** callback. ^If two or more such blocked connections have specified the 8299 ** same callback function, then instead of invoking the callback function 8300 ** multiple times, it is invoked once with the set of void* context pointers 8301 ** specified by the blocked connections bundled together into an array. 8302 ** This gives the application an opportunity to prioritize any actions 8303 ** related to the set of unblocked database connections. 8304 ** 8305 ** <b>Deadlock Detection</b> 8306 ** 8307 ** Assuming that after registering for an unlock-notify callback a 8308 ** database waits for the callback to be issued before taking any further 8309 ** action (a reasonable assumption), then using this API may cause the 8310 ** application to deadlock. For example, if connection X is waiting for 8311 ** connection Y's transaction to be concluded, and similarly connection 8312 ** Y is waiting on connection X's transaction, then neither connection 8313 ** will proceed and the system may remain deadlocked indefinitely. 8314 ** 8315 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8316 ** detection. ^If a given call to sqlite3_unlock_notify() would put the 8317 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8318 ** unlock-notify callback is registered. The system is said to be in 8319 ** a deadlocked state if connection A has registered for an unlock-notify 8320 ** callback on the conclusion of connection B's transaction, and connection 8321 ** B has itself registered for an unlock-notify callback when connection 8322 ** A's transaction is concluded. ^Indirect deadlock is also detected, so 8323 ** the system is also considered to be deadlocked if connection B has 8324 ** registered for an unlock-notify callback on the conclusion of connection 8325 ** C's transaction, where connection C is waiting on connection A. ^Any 8326 ** number of levels of indirection are allowed. 8327 ** 8328 ** <b>The "DROP TABLE" Exception</b> 8329 ** 8330 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8331 ** always appropriate to call sqlite3_unlock_notify(). There is however, 8332 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8333 ** SQLite checks if there are any currently executing SELECT statements 8334 ** that belong to the same connection. If there are, SQLITE_LOCKED is 8335 ** returned. In this case there is no "blocking connection", so invoking 8336 ** sqlite3_unlock_notify() results in the unlock-notify callback being 8337 ** invoked immediately. If the application then re-attempts the "DROP TABLE" 8338 ** or "DROP INDEX" query, an infinite loop might be the result. 8339 ** 8340 ** One way around this problem is to check the extended error code returned 8341 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8342 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8343 ** the special "DROP TABLE/INDEX" case, the extended error code is just 8344 ** SQLITE_LOCKED.)^ 8345 */ 8346 SQLITE_API int sqlite3_unlock_notify( 8347 sqlite3 *pBlocked, /* Waiting connection */ 8348 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8349 void *pNotifyArg /* Argument to pass to xNotify */ 8350 ); 8351 8352 8353 /* 8354 ** CAPI3REF: String Comparison 8355 ** 8356 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8357 ** and extensions to compare the contents of two buffers containing UTF-8 8358 ** strings in a case-independent fashion, using the same definition of "case 8359 ** independence" that SQLite uses internally when comparing identifiers. 8360 */ 8361 SQLITE_API int sqlite3_stricmp(const char *, const char *); 8362 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 8363 8364 /* 8365 ** CAPI3REF: String Globbing 8366 * 8367 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8368 ** string X matches the [GLOB] pattern P. 8369 ** ^The definition of [GLOB] pattern matching used in 8370 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8371 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8372 ** is case sensitive. 8373 ** 8374 ** Note that this routine returns zero on a match and non-zero if the strings 8375 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8376 ** 8377 ** See also: [sqlite3_strlike()]. 8378 */ 8379 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 8380 8381 /* 8382 ** CAPI3REF: String LIKE Matching 8383 * 8384 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8385 ** string X matches the [LIKE] pattern P with escape character E. 8386 ** ^The definition of [LIKE] pattern matching used in 8387 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8388 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8389 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8390 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8391 ** insensitive - equivalent upper and lower case ASCII characters match 8392 ** one another. 8393 ** 8394 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8395 ** only ASCII characters are case folded. 8396 ** 8397 ** Note that this routine returns zero on a match and non-zero if the strings 8398 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8399 ** 8400 ** See also: [sqlite3_strglob()]. 8401 */ 8402 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8403 8404 /* 8405 ** CAPI3REF: Error Logging Interface 8406 ** 8407 ** ^The [sqlite3_log()] interface writes a message into the [error log] 8408 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8409 ** ^If logging is enabled, the zFormat string and subsequent arguments are 8410 ** used with [sqlite3_snprintf()] to generate the final output string. 8411 ** 8412 ** The sqlite3_log() interface is intended for use by extensions such as 8413 ** virtual tables, collating functions, and SQL functions. While there is 8414 ** nothing to prevent an application from calling sqlite3_log(), doing so 8415 ** is considered bad form. 8416 ** 8417 ** The zFormat string must not be NULL. 8418 ** 8419 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8420 ** will not use dynamically allocated memory. The log message is stored in 8421 ** a fixed-length buffer on the stack. If the log message is longer than 8422 ** a few hundred characters, it will be truncated to the length of the 8423 ** buffer. 8424 */ 8425 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 8426 8427 /* 8428 ** CAPI3REF: Write-Ahead Log Commit Hook 8429 ** METHOD: sqlite3 8430 ** 8431 ** ^The [sqlite3_wal_hook()] function is used to register a callback that 8432 ** is invoked each time data is committed to a database in wal mode. 8433 ** 8434 ** ^(The callback is invoked by SQLite after the commit has taken place and 8435 ** the associated write-lock on the database released)^, so the implementation 8436 ** may read, write or [checkpoint] the database as required. 8437 ** 8438 ** ^The first parameter passed to the callback function when it is invoked 8439 ** is a copy of the third parameter passed to sqlite3_wal_hook() when 8440 ** registering the callback. ^The second is a copy of the database handle. 8441 ** ^The third parameter is the name of the database that was written to - 8442 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8443 ** is the number of pages currently in the write-ahead log file, 8444 ** including those that were just committed. 8445 ** 8446 ** The callback function should normally return [SQLITE_OK]. ^If an error 8447 ** code is returned, that error will propagate back up through the 8448 ** SQLite code base to cause the statement that provoked the callback 8449 ** to report an error, though the commit will have still occurred. If the 8450 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8451 ** that does not correspond to any valid SQLite error code, the results 8452 ** are undefined. 8453 ** 8454 ** A single database handle may have at most a single write-ahead log callback 8455 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8456 ** previously registered write-ahead log callback. ^Note that the 8457 ** [sqlite3_wal_autocheckpoint()] interface and the 8458 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8459 ** overwrite any prior [sqlite3_wal_hook()] settings. 8460 */ 8461 SQLITE_API void *sqlite3_wal_hook( 8462 sqlite3*, 8463 int(*)(void *,sqlite3*,const char*,int), 8464 void* 8465 ); 8466 8467 /* 8468 ** CAPI3REF: Configure an auto-checkpoint 8469 ** METHOD: sqlite3 8470 ** 8471 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8472 ** [sqlite3_wal_hook()] that causes any database on [database connection] D 8473 ** to automatically [checkpoint] 8474 ** after committing a transaction if there are N or 8475 ** more frames in the [write-ahead log] file. ^Passing zero or 8476 ** a negative value as the nFrame parameter disables automatic 8477 ** checkpoints entirely. 8478 ** 8479 ** ^The callback registered by this function replaces any existing callback 8480 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8481 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8482 ** configured by this function. 8483 ** 8484 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8485 ** from SQL. 8486 ** 8487 ** ^Checkpoints initiated by this mechanism are 8488 ** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8489 ** 8490 ** ^Every new [database connection] defaults to having the auto-checkpoint 8491 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8492 ** pages. The use of this interface 8493 ** is only necessary if the default setting is found to be suboptimal 8494 ** for a particular application. 8495 */ 8496 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8497 8498 /* 8499 ** CAPI3REF: Checkpoint a database 8500 ** METHOD: sqlite3 8501 ** 8502 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8503 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8504 ** 8505 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8506 ** [write-ahead log] for database X on [database connection] D to be 8507 ** transferred into the database file and for the write-ahead log to 8508 ** be reset. See the [checkpointing] documentation for addition 8509 ** information. 8510 ** 8511 ** This interface used to be the only way to cause a checkpoint to 8512 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8513 ** interface was added. This interface is retained for backwards 8514 ** compatibility and as a convenience for applications that need to manually 8515 ** start a callback but which do not need the full power (and corresponding 8516 ** complication) of [sqlite3_wal_checkpoint_v2()]. 8517 */ 8518 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8519 8520 /* 8521 ** CAPI3REF: Checkpoint a database 8522 ** METHOD: sqlite3 8523 ** 8524 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8525 ** operation on database X of [database connection] D in mode M. Status 8526 ** information is written back into integers pointed to by L and C.)^ 8527 ** ^(The M parameter must be a valid [checkpoint mode]:)^ 8528 ** 8529 ** <dl> 8530 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8531 ** ^Checkpoint as many frames as possible without waiting for any database 8532 ** readers or writers to finish, then sync the database file if all frames 8533 ** in the log were checkpointed. ^The [busy-handler callback] 8534 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8535 ** ^On the other hand, passive mode might leave the checkpoint unfinished 8536 ** if there are concurrent readers or writers. 8537 ** 8538 ** <dt>SQLITE_CHECKPOINT_FULL<dd> 8539 ** ^This mode blocks (it invokes the 8540 ** [sqlite3_busy_handler|busy-handler callback]) until there is no 8541 ** database writer and all readers are reading from the most recent database 8542 ** snapshot. ^It then checkpoints all frames in the log file and syncs the 8543 ** database file. ^This mode blocks new database writers while it is pending, 8544 ** but new database readers are allowed to continue unimpeded. 8545 ** 8546 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8547 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8548 ** that after checkpointing the log file it blocks (calls the 8549 ** [busy-handler callback]) 8550 ** until all readers are reading from the database file only. ^This ensures 8551 ** that the next writer will restart the log file from the beginning. 8552 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8553 ** database writer attempts while it is pending, but does not impede readers. 8554 ** 8555 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8556 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8557 ** addition that it also truncates the log file to zero bytes just prior 8558 ** to a successful return. 8559 ** </dl> 8560 ** 8561 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8562 ** the log file or to -1 if the checkpoint could not run because 8563 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8564 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8565 ** log file (including any that were already checkpointed before the function 8566 ** was called) or to -1 if the checkpoint could not run due to an error or 8567 ** because the database is not in WAL mode. ^Note that upon successful 8568 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8569 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8570 ** 8571 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8572 ** any other process is running a checkpoint operation at the same time, the 8573 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8574 ** busy-handler configured, it will not be invoked in this case. 8575 ** 8576 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8577 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8578 ** obtained immediately, and a busy-handler is configured, it is invoked and 8579 ** the writer lock retried until either the busy-handler returns 0 or the lock 8580 ** is successfully obtained. ^The busy-handler is also invoked while waiting for 8581 ** database readers as described above. ^If the busy-handler returns 0 before 8582 ** the writer lock is obtained or while waiting for database readers, the 8583 ** checkpoint operation proceeds from that point in the same way as 8584 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8585 ** without blocking any further. ^SQLITE_BUSY is returned in this case. 8586 ** 8587 ** ^If parameter zDb is NULL or points to a zero length string, then the 8588 ** specified operation is attempted on all WAL databases [attached] to 8589 ** [database connection] db. In this case the 8590 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8591 ** an SQLITE_BUSY error is encountered when processing one or more of the 8592 ** attached WAL databases, the operation is still attempted on any remaining 8593 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8594 ** error occurs while processing an attached database, processing is abandoned 8595 ** and the error code is returned to the caller immediately. ^If no error 8596 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8597 ** databases, SQLITE_OK is returned. 8598 ** 8599 ** ^If database zDb is the name of an attached database that is not in WAL 8600 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8601 ** zDb is not NULL (or a zero length string) and is not the name of any 8602 ** attached database, SQLITE_ERROR is returned to the caller. 8603 ** 8604 ** ^Unless it returns SQLITE_MISUSE, 8605 ** the sqlite3_wal_checkpoint_v2() interface 8606 ** sets the error information that is queried by 8607 ** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8608 ** 8609 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8610 ** from SQL. 8611 */ 8612 SQLITE_API int sqlite3_wal_checkpoint_v2( 8613 sqlite3 *db, /* Database handle */ 8614 const char *zDb, /* Name of attached database (or NULL) */ 8615 int eMode, /* SQLITE_CHECKPOINT_* value */ 8616 int *pnLog, /* OUT: Size of WAL log in frames */ 8617 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8618 ); 8619 8620 /* 8621 ** CAPI3REF: Checkpoint Mode Values 8622 ** KEYWORDS: {checkpoint mode} 8623 ** 8624 ** These constants define all valid values for the "checkpoint mode" passed 8625 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8626 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8627 ** meaning of each of these checkpoint modes. 8628 */ 8629 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8630 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8631 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8632 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8633 8634 /* 8635 ** CAPI3REF: Virtual Table Interface Configuration 8636 ** 8637 ** This function may be called by either the [xConnect] or [xCreate] method 8638 ** of a [virtual table] implementation to configure 8639 ** various facets of the virtual table interface. 8640 ** 8641 ** If this interface is invoked outside the context of an xConnect or 8642 ** xCreate virtual table method then the behavior is undefined. 8643 ** 8644 ** At present, there is only one option that may be configured using 8645 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8646 ** may be added in the future. 8647 */ 8648 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 8649 8650 /* 8651 ** CAPI3REF: Virtual Table Configuration Options 8652 ** 8653 ** These macros define the various options to the 8654 ** [sqlite3_vtab_config()] interface that [virtual table] implementations 8655 ** can use to customize and optimize their behavior. 8656 ** 8657 ** <dl> 8658 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8659 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8660 ** <dd>Calls of the form 8661 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8662 ** where X is an integer. If X is zero, then the [virtual table] whose 8663 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8664 ** support constraints. In this configuration (which is the default) if 8665 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8666 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8667 ** specified as part of the users SQL statement, regardless of the actual 8668 ** ON CONFLICT mode specified. 8669 ** 8670 ** If X is non-zero, then the virtual table implementation guarantees 8671 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8672 ** any modifications to internal or persistent data structures have been made. 8673 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8674 ** is able to roll back a statement or database transaction, and abandon 8675 ** or continue processing the current SQL statement as appropriate. 8676 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8677 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8678 ** had been ABORT. 8679 ** 8680 ** Virtual table implementations that are required to handle OR REPLACE 8681 ** must do so within the [xUpdate] method. If a call to the 8682 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8683 ** CONFLICT policy is REPLACE, the virtual table implementation should 8684 ** silently replace the appropriate rows within the xUpdate callback and 8685 ** return SQLITE_OK. Or, if this is not possible, it may return 8686 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8687 ** constraint handling. 8688 ** </dl> 8689 */ 8690 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8691 8692 /* 8693 ** CAPI3REF: Determine The Virtual Table Conflict Policy 8694 ** 8695 ** This function may only be called from within a call to the [xUpdate] method 8696 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8697 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8698 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8699 ** of the SQL statement that triggered the call to the [xUpdate] method of the 8700 ** [virtual table]. 8701 */ 8702 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 8703 8704 /* 8705 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8706 ** 8707 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8708 ** method of a [virtual table], then it returns true if and only if the 8709 ** column is being fetched as part of an UPDATE operation during which the 8710 ** column value will not change. Applications might use this to substitute 8711 ** a return value that is less expensive to compute and that the corresponding 8712 ** [xUpdate] method understands as a "no-change" value. 8713 ** 8714 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8715 ** the column is not changed by the UPDATE statement, then the xColumn 8716 ** method can optionally return without setting a result, without calling 8717 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8718 ** In that case, [sqlite3_value_nochange(X)] will return true for the 8719 ** same column in the [xUpdate] method. 8720 */ 8721 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 8722 8723 /* 8724 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8725 ** 8726 ** This function may only be called from within a call to the [xBestIndex] 8727 ** method of a [virtual table]. 8728 ** 8729 ** The first argument must be the sqlite3_index_info object that is the 8730 ** first parameter to the xBestIndex() method. The second argument must be 8731 ** an index into the aConstraint[] array belonging to the sqlite3_index_info 8732 ** structure passed to xBestIndex. This function returns a pointer to a buffer 8733 ** containing the name of the collation sequence for the corresponding 8734 ** constraint. 8735 */ 8736 SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8737 8738 /* 8739 ** CAPI3REF: Conflict resolution modes 8740 ** KEYWORDS: {conflict resolution mode} 8741 ** 8742 ** These constants are returned by [sqlite3_vtab_on_conflict()] to 8743 ** inform a [virtual table] implementation what the [ON CONFLICT] mode 8744 ** is for the SQL statement being evaluated. 8745 ** 8746 ** Note that the [SQLITE_IGNORE] constant is also used as a potential 8747 ** return value from the [sqlite3_set_authorizer()] callback and that 8748 ** [SQLITE_ABORT] is also a [result code]. 8749 */ 8750 #define SQLITE_ROLLBACK 1 8751 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8752 #define SQLITE_FAIL 3 8753 /* #define SQLITE_ABORT 4 // Also an error code */ 8754 #define SQLITE_REPLACE 5 8755 8756 /* 8757 ** CAPI3REF: Prepared Statement Scan Status Opcodes 8758 ** KEYWORDS: {scanstatus options} 8759 ** 8760 ** The following constants can be used for the T parameter to the 8761 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8762 ** different metric for sqlite3_stmt_scanstatus() to return. 8763 ** 8764 ** When the value returned to V is a string, space to hold that string is 8765 ** managed by the prepared statement S and will be automatically freed when 8766 ** S is finalized. 8767 ** 8768 ** <dl> 8769 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8770 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8771 ** set to the total number of times that the X-th loop has run.</dd> 8772 ** 8773 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8774 ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8775 ** to the total number of rows examined by all iterations of the X-th loop.</dd> 8776 ** 8777 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8778 ** <dd>^The "double" variable pointed to by the T parameter will be set to the 8779 ** query planner's estimate for the average number of rows output from each 8780 ** iteration of the X-th loop. If the query planner's estimates was accurate, 8781 ** then this value will approximate the quotient NVISIT/NLOOP and the 8782 ** product of this value for all prior loops with the same SELECTID will 8783 ** be the NLOOP value for the current loop. 8784 ** 8785 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8786 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8787 ** to a zero-terminated UTF-8 string containing the name of the index or table 8788 ** used for the X-th loop. 8789 ** 8790 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8791 ** <dd>^The "const char *" variable pointed to by the T parameter will be set 8792 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8793 ** description for the X-th loop. 8794 ** 8795 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8796 ** <dd>^The "int" variable pointed to by the T parameter will be set to the 8797 ** "select-id" for the X-th loop. The select-id identifies which query or 8798 ** subquery the loop is part of. The main query has a select-id of zero. 8799 ** The select-id is the same value as is output in the first column 8800 ** of an [EXPLAIN QUERY PLAN] query. 8801 ** </dl> 8802 */ 8803 #define SQLITE_SCANSTAT_NLOOP 0 8804 #define SQLITE_SCANSTAT_NVISIT 1 8805 #define SQLITE_SCANSTAT_EST 2 8806 #define SQLITE_SCANSTAT_NAME 3 8807 #define SQLITE_SCANSTAT_EXPLAIN 4 8808 #define SQLITE_SCANSTAT_SELECTID 5 8809 8810 /* 8811 ** CAPI3REF: Prepared Statement Scan Status 8812 ** METHOD: sqlite3_stmt 8813 ** 8814 ** This interface returns information about the predicted and measured 8815 ** performance for pStmt. Advanced applications can use this 8816 ** interface to compare the predicted and the measured performance and 8817 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8818 ** 8819 ** Since this interface is expected to be rarely used, it is only 8820 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8821 ** compile-time option. 8822 ** 8823 ** The "iScanStatusOp" parameter determines which status information to return. 8824 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8825 ** of this interface is undefined. 8826 ** ^The requested measurement is written into a variable pointed to by 8827 ** the "pOut" parameter. 8828 ** Parameter "idx" identifies the specific loop to retrieve statistics for. 8829 ** Loops are numbered starting from zero. ^If idx is out of range - less than 8830 ** zero or greater than or equal to the total number of loops used to implement 8831 ** the statement - a non-zero value is returned and the variable that pOut 8832 ** points to is unchanged. 8833 ** 8834 ** ^Statistics might not be available for all loops in all statements. ^In cases 8835 ** where there exist loops with no available statistics, this function behaves 8836 ** as if the loop did not exist - it returns non-zero and leave the variable 8837 ** that pOut points to unchanged. 8838 ** 8839 ** See also: [sqlite3_stmt_scanstatus_reset()] 8840 */ 8841 SQLITE_API int sqlite3_stmt_scanstatus( 8842 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8843 int idx, /* Index of loop to report on */ 8844 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8845 void *pOut /* Result written here */ 8846 ); 8847 8848 /* 8849 ** CAPI3REF: Zero Scan-Status Counters 8850 ** METHOD: sqlite3_stmt 8851 ** 8852 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8853 ** 8854 ** This API is only available if the library is built with pre-processor 8855 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8856 */ 8857 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8858 8859 /* 8860 ** CAPI3REF: Flush caches to disk mid-transaction 8861 ** 8862 ** ^If a write-transaction is open on [database connection] D when the 8863 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8864 ** pages in the pager-cache that are not currently in use are written out 8865 ** to disk. A dirty page may be in use if a database cursor created by an 8866 ** active SQL statement is reading from it, or if it is page 1 of a database 8867 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8868 ** interface flushes caches for all schemas - "main", "temp", and 8869 ** any [attached] databases. 8870 ** 8871 ** ^If this function needs to obtain extra database locks before dirty pages 8872 ** can be flushed to disk, it does so. ^If those locks cannot be obtained 8873 ** immediately and there is a busy-handler callback configured, it is invoked 8874 ** in the usual manner. ^If the required lock still cannot be obtained, then 8875 ** the database is skipped and an attempt made to flush any dirty pages 8876 ** belonging to the next (if any) database. ^If any databases are skipped 8877 ** because locks cannot be obtained, but no other error occurs, this 8878 ** function returns SQLITE_BUSY. 8879 ** 8880 ** ^If any other error occurs while flushing dirty pages to disk (for 8881 ** example an IO error or out-of-memory condition), then processing is 8882 ** abandoned and an SQLite [error code] is returned to the caller immediately. 8883 ** 8884 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8885 ** 8886 ** ^This function does not set the database handle error code or message 8887 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8888 */ 8889 SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 8890 8891 /* 8892 ** CAPI3REF: The pre-update hook. 8893 ** 8894 ** ^These interfaces are only available if SQLite is compiled using the 8895 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8896 ** 8897 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8898 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8899 ** on a database table. 8900 ** ^At most one preupdate hook may be registered at a time on a single 8901 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8902 ** the previous setting. 8903 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8904 ** with a NULL pointer as the second parameter. 8905 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8906 ** the first parameter to callbacks. 8907 ** 8908 ** ^The preupdate hook only fires for changes to real database tables; the 8909 ** preupdate hook is not invoked for changes to [virtual tables] or to 8910 ** system tables like sqlite_master or sqlite_stat1. 8911 ** 8912 ** ^The second parameter to the preupdate callback is a pointer to 8913 ** the [database connection] that registered the preupdate hook. 8914 ** ^The third parameter to the preupdate callback is one of the constants 8915 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8916 ** kind of update operation that is about to occur. 8917 ** ^(The fourth parameter to the preupdate callback is the name of the 8918 ** database within the database connection that is being modified. This 8919 ** will be "main" for the main database or "temp" for TEMP tables or 8920 ** the name given after the AS keyword in the [ATTACH] statement for attached 8921 ** databases.)^ 8922 ** ^The fifth parameter to the preupdate callback is the name of the 8923 ** table that is being modified. 8924 ** 8925 ** For an UPDATE or DELETE operation on a [rowid table], the sixth 8926 ** parameter passed to the preupdate callback is the initial [rowid] of the 8927 ** row being modified or deleted. For an INSERT operation on a rowid table, 8928 ** or any operation on a WITHOUT ROWID table, the value of the sixth 8929 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8930 ** seventh parameter is the final rowid value of the row being inserted 8931 ** or updated. The value of the seventh parameter passed to the callback 8932 ** function is not defined for operations on WITHOUT ROWID tables, or for 8933 ** INSERT operations on rowid tables. 8934 ** 8935 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8936 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8937 ** provide additional information about a preupdate event. These routines 8938 ** may only be called from within a preupdate callback. Invoking any of 8939 ** these routines from outside of a preupdate callback or with a 8940 ** [database connection] pointer that is different from the one supplied 8941 ** to the preupdate callback results in undefined and probably undesirable 8942 ** behavior. 8943 ** 8944 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8945 ** in the row that is being inserted, updated, or deleted. 8946 ** 8947 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8948 ** a [protected sqlite3_value] that contains the value of the Nth column of 8949 ** the table row before it is updated. The N parameter must be between 0 8950 ** and one less than the number of columns or the behavior will be 8951 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8952 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8953 ** behavior is undefined. The [sqlite3_value] that P points to 8954 ** will be destroyed when the preupdate callback returns. 8955 ** 8956 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8957 ** a [protected sqlite3_value] that contains the value of the Nth column of 8958 ** the table row after it is updated. The N parameter must be between 0 8959 ** and one less than the number of columns or the behavior will be 8960 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8961 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8962 ** behavior is undefined. The [sqlite3_value] that P points to 8963 ** will be destroyed when the preupdate callback returns. 8964 ** 8965 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8966 ** callback was invoked as a result of a direct insert, update, or delete 8967 ** operation; or 1 for inserts, updates, or deletes invoked by top-level 8968 ** triggers; or 2 for changes resulting from triggers called by top-level 8969 ** triggers; and so forth. 8970 ** 8971 ** See also: [sqlite3_update_hook()] 8972 */ 8973 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8974 SQLITE_API void *sqlite3_preupdate_hook( 8975 sqlite3 *db, 8976 void(*xPreUpdate)( 8977 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8978 sqlite3 *db, /* Database handle */ 8979 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8980 char const *zDb, /* Database name */ 8981 char const *zName, /* Table name */ 8982 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8983 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8984 ), 8985 void* 8986 ); 8987 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8988 SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 8989 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 8990 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8991 #endif 8992 8993 /* 8994 ** CAPI3REF: Low-level system error code 8995 ** 8996 ** ^Attempt to return the underlying operating system error code or error 8997 ** number that caused the most recent I/O error or failure to open a file. 8998 ** The return value is OS-dependent. For example, on unix systems, after 8999 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9000 ** called to get back the underlying "errno" that caused the problem, such 9001 ** as ENOSPC, EAUTH, EISDIR, and so forth. 9002 */ 9003 SQLITE_API int sqlite3_system_errno(sqlite3*); 9004 9005 /* 9006 ** CAPI3REF: Database Snapshot 9007 ** KEYWORDS: {snapshot} {sqlite3_snapshot} 9008 ** 9009 ** An instance of the snapshot object records the state of a [WAL mode] 9010 ** database for some specific point in history. 9011 ** 9012 ** In [WAL mode], multiple [database connections] that are open on the 9013 ** same database file can each be reading a different historical version 9014 ** of the database file. When a [database connection] begins a read 9015 ** transaction, that connection sees an unchanging copy of the database 9016 ** as it existed for the point in time when the transaction first started. 9017 ** Subsequent changes to the database from other connections are not seen 9018 ** by the reader until a new read transaction is started. 9019 ** 9020 ** The sqlite3_snapshot object records state information about an historical 9021 ** version of the database file so that it is possible to later open a new read 9022 ** transaction that sees that historical version of the database rather than 9023 ** the most recent version. 9024 */ 9025 typedef struct sqlite3_snapshot { 9026 unsigned char hidden[48]; 9027 } sqlite3_snapshot; 9028 9029 /* 9030 ** CAPI3REF: Record A Database Snapshot 9031 ** CONSTRUCTOR: sqlite3_snapshot 9032 ** 9033 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9034 ** new [sqlite3_snapshot] object that records the current state of 9035 ** schema S in database connection D. ^On success, the 9036 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9037 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9038 ** If there is not already a read-transaction open on schema S when 9039 ** this function is called, one is opened automatically. 9040 ** 9041 ** The following must be true for this function to succeed. If any of 9042 ** the following statements are false when sqlite3_snapshot_get() is 9043 ** called, SQLITE_ERROR is returned. The final value of *P is undefined 9044 ** in this case. 9045 ** 9046 ** <ul> 9047 ** <li> The database handle must not be in [autocommit mode]. 9048 ** 9049 ** <li> Schema S of [database connection] D must be a [WAL mode] database. 9050 ** 9051 ** <li> There must not be a write transaction open on schema S of database 9052 ** connection D. 9053 ** 9054 ** <li> One or more transactions must have been written to the current wal 9055 ** file since it was created on disk (by any connection). This means 9056 ** that a snapshot cannot be taken on a wal mode database with no wal 9057 ** file immediately after it is first opened. At least one transaction 9058 ** must be written to it first. 9059 ** </ul> 9060 ** 9061 ** This function may also return SQLITE_NOMEM. If it is called with the 9062 ** database handle in autocommit mode but fails for some other reason, 9063 ** whether or not a read transaction is opened on schema S is undefined. 9064 ** 9065 ** The [sqlite3_snapshot] object returned from a successful call to 9066 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9067 ** to avoid a memory leak. 9068 ** 9069 ** The [sqlite3_snapshot_get()] interface is only available when the 9070 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9071 */ 9072 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9073 sqlite3 *db, 9074 const char *zSchema, 9075 sqlite3_snapshot **ppSnapshot 9076 ); 9077 9078 /* 9079 ** CAPI3REF: Start a read transaction on an historical snapshot 9080 ** METHOD: sqlite3_snapshot 9081 ** 9082 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9083 ** transaction or upgrades an existing one for schema S of 9084 ** [database connection] D such that the read transaction refers to 9085 ** historical [snapshot] P, rather than the most recent change to the 9086 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9087 ** on success or an appropriate [error code] if it fails. 9088 ** 9089 ** ^In order to succeed, the database connection must not be in 9090 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9091 ** is already a read transaction open on schema S, then the database handle 9092 ** must have no active statements (SELECT statements that have been passed 9093 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9094 ** SQLITE_ERROR is returned if either of these conditions is violated, or 9095 ** if schema S does not exist, or if the snapshot object is invalid. 9096 ** 9097 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9098 ** snapshot has been overwritten by a [checkpoint]. In this case 9099 ** SQLITE_ERROR_SNAPSHOT is returned. 9100 ** 9101 ** If there is already a read transaction open when this function is 9102 ** invoked, then the same read transaction remains open (on the same 9103 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9104 ** is returned. If another error code - for example SQLITE_PROTOCOL or an 9105 ** SQLITE_IOERR error code - is returned, then the final state of the 9106 ** read transaction is undefined. If SQLITE_OK is returned, then the 9107 ** read transaction is now open on database snapshot P. 9108 ** 9109 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9110 ** database connection D does not know that the database file for 9111 ** schema S is in [WAL mode]. A database connection might not know 9112 ** that the database file is in [WAL mode] if there has been no prior 9113 ** I/O on that database connection, or if the database entered [WAL mode] 9114 ** after the most recent I/O on the database connection.)^ 9115 ** (Hint: Run "[PRAGMA application_id]" against a newly opened 9116 ** database connection in order to make it ready to use snapshots.) 9117 ** 9118 ** The [sqlite3_snapshot_open()] interface is only available when the 9119 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9120 */ 9121 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9122 sqlite3 *db, 9123 const char *zSchema, 9124 sqlite3_snapshot *pSnapshot 9125 ); 9126 9127 /* 9128 ** CAPI3REF: Destroy a snapshot 9129 ** DESTRUCTOR: sqlite3_snapshot 9130 ** 9131 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9132 ** The application must eventually free every [sqlite3_snapshot] object 9133 ** using this routine to avoid a memory leak. 9134 ** 9135 ** The [sqlite3_snapshot_free()] interface is only available when the 9136 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9137 */ 9138 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9139 9140 /* 9141 ** CAPI3REF: Compare the ages of two snapshot handles. 9142 ** METHOD: sqlite3_snapshot 9143 ** 9144 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9145 ** of two valid snapshot handles. 9146 ** 9147 ** If the two snapshot handles are not associated with the same database 9148 ** file, the result of the comparison is undefined. 9149 ** 9150 ** Additionally, the result of the comparison is only valid if both of the 9151 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9152 ** last time the wal file was deleted. The wal file is deleted when the 9153 ** database is changed back to rollback mode or when the number of database 9154 ** clients drops to zero. If either snapshot handle was obtained before the 9155 ** wal file was last deleted, the value returned by this function 9156 ** is undefined. 9157 ** 9158 ** Otherwise, this API returns a negative value if P1 refers to an older 9159 ** snapshot than P2, zero if the two handles refer to the same database 9160 ** snapshot, and a positive value if P1 is a newer snapshot than P2. 9161 ** 9162 ** This interface is only available if SQLite is compiled with the 9163 ** [SQLITE_ENABLE_SNAPSHOT] option. 9164 */ 9165 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9166 sqlite3_snapshot *p1, 9167 sqlite3_snapshot *p2 9168 ); 9169 9170 /* 9171 ** CAPI3REF: Recover snapshots from a wal file 9172 ** METHOD: sqlite3_snapshot 9173 ** 9174 ** If a [WAL file] remains on disk after all database connections close 9175 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9176 ** or because the last process to have the database opened exited without 9177 ** calling [sqlite3_close()]) and a new connection is subsequently opened 9178 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9179 ** will only be able to open the last transaction added to the WAL file 9180 ** even though the WAL file contains other valid transactions. 9181 ** 9182 ** This function attempts to scan the WAL file associated with database zDb 9183 ** of database handle db and make all valid snapshots available to 9184 ** sqlite3_snapshot_open(). It is an error if there is already a read 9185 ** transaction open on the database, or if the database is not a WAL mode 9186 ** database. 9187 ** 9188 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9189 ** 9190 ** This interface is only available if SQLite is compiled with the 9191 ** [SQLITE_ENABLE_SNAPSHOT] option. 9192 */ 9193 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9194 9195 /* 9196 ** CAPI3REF: Serialize a database 9197 ** 9198 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9199 ** that is a serialization of the S database on [database connection] D. 9200 ** If P is not a NULL pointer, then the size of the database in bytes 9201 ** is written into *P. 9202 ** 9203 ** For an ordinary on-disk database file, the serialization is just a 9204 ** copy of the disk file. For an in-memory database or a "TEMP" database, 9205 ** the serialization is the same sequence of bytes which would be written 9206 ** to disk if that database where backed up to disk. 9207 ** 9208 ** The usual case is that sqlite3_serialize() copies the serialization of 9209 ** the database into memory obtained from [sqlite3_malloc64()] and returns 9210 ** a pointer to that memory. The caller is responsible for freeing the 9211 ** returned value to avoid a memory leak. However, if the F argument 9212 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9213 ** are made, and the sqlite3_serialize() function will return a pointer 9214 ** to the contiguous memory representation of the database that SQLite 9215 ** is currently using for that database, or NULL if the no such contiguous 9216 ** memory representation of the database exists. A contiguous memory 9217 ** representation of the database will usually only exist if there has 9218 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9219 ** values of D and S. 9220 ** The size of the database is written into *P even if the 9221 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9222 ** of the database exists. 9223 ** 9224 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9225 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9226 ** allocation error occurs. 9227 ** 9228 ** This interface is only available if SQLite is compiled with the 9229 ** [SQLITE_ENABLE_DESERIALIZE] option. 9230 */ 9231 SQLITE_API unsigned char *sqlite3_serialize( 9232 sqlite3 *db, /* The database connection */ 9233 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9234 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9235 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9236 ); 9237 9238 /* 9239 ** CAPI3REF: Flags for sqlite3_serialize 9240 ** 9241 ** Zero or more of the following constants can be OR-ed together for 9242 ** the F argument to [sqlite3_serialize(D,S,P,F)]. 9243 ** 9244 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9245 ** a pointer to contiguous in-memory database that it is currently using, 9246 ** without making a copy of the database. If SQLite is not currently using 9247 ** a contiguous in-memory database, then this option causes 9248 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9249 ** using a contiguous in-memory database if it has been initialized by a 9250 ** prior call to [sqlite3_deserialize()]. 9251 */ 9252 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9253 9254 /* 9255 ** CAPI3REF: Deserialize a database 9256 ** 9257 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9258 ** [database connection] D to disconnect from database S and then 9259 ** reopen S as an in-memory database based on the serialization contained 9260 ** in P. The serialized database P is N bytes in size. M is the size of 9261 ** the buffer P, which might be larger than N. If M is larger than N, and 9262 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9263 ** permitted to add content to the in-memory database as long as the total 9264 ** size does not exceed M bytes. 9265 ** 9266 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9267 ** invoke sqlite3_free() on the serialization buffer when the database 9268 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9269 ** SQLite will try to increase the buffer size using sqlite3_realloc64() 9270 ** if writes on the database cause it to grow larger than M bytes. 9271 ** 9272 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9273 ** database is currently in a read transaction or is involved in a backup 9274 ** operation. 9275 ** 9276 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9277 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9278 ** [sqlite3_free()] is invoked on argument P prior to returning. 9279 ** 9280 ** This interface is only available if SQLite is compiled with the 9281 ** [SQLITE_ENABLE_DESERIALIZE] option. 9282 */ 9283 SQLITE_API int sqlite3_deserialize( 9284 sqlite3 *db, /* The database connection */ 9285 const char *zSchema, /* Which DB to reopen with the deserialization */ 9286 unsigned char *pData, /* The serialized database content */ 9287 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9288 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9289 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9290 ); 9291 9292 /* 9293 ** CAPI3REF: Flags for sqlite3_deserialize() 9294 ** 9295 ** The following are allowed values for 6th argument (the F argument) to 9296 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9297 ** 9298 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9299 ** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9300 ** and that SQLite should take ownership of this memory and automatically 9301 ** free it when it has finished using it. Without this flag, the caller 9302 ** is responsible for freeing any dynamically allocated memory. 9303 ** 9304 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9305 ** grow the size of the database using calls to [sqlite3_realloc64()]. This 9306 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9307 ** Without this flag, the deserialized database cannot increase in size beyond 9308 ** the number of bytes specified by the M parameter. 9309 ** 9310 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9311 ** should be treated as read-only. 9312 */ 9313 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9314 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9315 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9316 9317 /* 9318 ** Undo the hack that converts floating point types to integer for 9319 ** builds on processors without floating point support. 9320 */ 9321 #ifdef SQLITE_OMIT_FLOATING_POINT 9322 # undef double 9323 #endif 9324 9325 #ifdef __cplusplus 9326 } /* End of the 'extern "C"' block */ 9327 #endif 9328 #endif /* SQLITE3_H */ 9329 9330 /******** Begin file sqlite3rtree.h *********/ 9331 /* 9332 ** 2010 August 30 9333 ** 9334 ** The author disclaims copyright to this source code. In place of 9335 ** a legal notice, here is a blessing: 9336 ** 9337 ** May you do good and not evil. 9338 ** May you find forgiveness for yourself and forgive others. 9339 ** May you share freely, never taking more than you give. 9340 ** 9341 ************************************************************************* 9342 */ 9343 9344 #ifndef _SQLITE3RTREE_H_ 9345 #define _SQLITE3RTREE_H_ 9346 9347 9348 #ifdef __cplusplus 9349 extern "C" { 9350 #endif 9351 9352 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 9353 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 9354 9355 /* The double-precision datatype used by RTree depends on the 9356 ** SQLITE_RTREE_INT_ONLY compile-time option. 9357 */ 9358 #ifdef SQLITE_RTREE_INT_ONLY 9359 typedef sqlite3_int64 sqlite3_rtree_dbl; 9360 #else 9361 typedef double sqlite3_rtree_dbl; 9362 #endif 9363 9364 /* 9365 ** Register a geometry callback named zGeom that can be used as part of an 9366 ** R-Tree geometry query as follows: 9367 ** 9368 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 9369 */ 9370 SQLITE_API int sqlite3_rtree_geometry_callback( 9371 sqlite3 *db, 9372 const char *zGeom, 9373 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 9374 void *pContext 9375 ); 9376 9377 9378 /* 9379 ** A pointer to a structure of the following type is passed as the first 9380 ** argument to callbacks registered using rtree_geometry_callback(). 9381 */ 9382 struct sqlite3_rtree_geometry { 9383 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 9384 int nParam; /* Size of array aParam[] */ 9385 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 9386 void *pUser; /* Callback implementation user data */ 9387 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 9388 }; 9389 9390 /* 9391 ** Register a 2nd-generation geometry callback named zScore that can be 9392 ** used as part of an R-Tree geometry query as follows: 9393 ** 9394 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 9395 */ 9396 SQLITE_API int sqlite3_rtree_query_callback( 9397 sqlite3 *db, 9398 const char *zQueryFunc, 9399 int (*xQueryFunc)(sqlite3_rtree_query_info*), 9400 void *pContext, 9401 void (*xDestructor)(void*) 9402 ); 9403 9404 9405 /* 9406 ** A pointer to a structure of the following type is passed as the 9407 ** argument to scored geometry callback registered using 9408 ** sqlite3_rtree_query_callback(). 9409 ** 9410 ** Note that the first 5 fields of this structure are identical to 9411 ** sqlite3_rtree_geometry. This structure is a subclass of 9412 ** sqlite3_rtree_geometry. 9413 */ 9414 struct sqlite3_rtree_query_info { 9415 void *pContext; /* pContext from when function registered */ 9416 int nParam; /* Number of function parameters */ 9417 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 9418 void *pUser; /* callback can use this, if desired */ 9419 void (*xDelUser)(void*); /* function to free pUser */ 9420 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 9421 unsigned int *anQueue; /* Number of pending entries in the queue */ 9422 int nCoord; /* Number of coordinates */ 9423 int iLevel; /* Level of current node or entry */ 9424 int mxLevel; /* The largest iLevel value in the tree */ 9425 sqlite3_int64 iRowid; /* Rowid for current entry */ 9426 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 9427 int eParentWithin; /* Visibility of parent node */ 9428 int eWithin; /* OUT: Visibility */ 9429 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 9430 /* The following fields are only available in 3.8.11 and later */ 9431 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 9432 }; 9433 9434 /* 9435 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 9436 */ 9437 #define NOT_WITHIN 0 /* Object completely outside of query region */ 9438 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 9439 #define FULLY_WITHIN 2 /* Object fully contained within query region */ 9440 9441 9442 #ifdef __cplusplus 9443 } /* end of the 'extern "C"' block */ 9444 #endif 9445 9446 #endif /* ifndef _SQLITE3RTREE_H_ */ 9447 9448 /******** End of sqlite3rtree.h *********/ 9449 /******** Begin file sqlite3session.h *********/ 9450 9451 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 9452 #define __SQLITESESSION_H_ 1 9453 9454 /* 9455 ** Make sure we can call this stuff from C++. 9456 */ 9457 #ifdef __cplusplus 9458 extern "C" { 9459 #endif 9460 9461 9462 /* 9463 ** CAPI3REF: Session Object Handle 9464 ** 9465 ** An instance of this object is a [session] that can be used to 9466 ** record changes to a database. 9467 */ 9468 typedef struct sqlite3_session sqlite3_session; 9469 9470 /* 9471 ** CAPI3REF: Changeset Iterator Handle 9472 ** 9473 ** An instance of this object acts as a cursor for iterating 9474 ** over the elements of a [changeset] or [patchset]. 9475 */ 9476 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 9477 9478 /* 9479 ** CAPI3REF: Create A New Session Object 9480 ** CONSTRUCTOR: sqlite3_session 9481 ** 9482 ** Create a new session object attached to database handle db. If successful, 9483 ** a pointer to the new object is written to *ppSession and SQLITE_OK is 9484 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite 9485 ** error code (e.g. SQLITE_NOMEM) is returned. 9486 ** 9487 ** It is possible to create multiple session objects attached to a single 9488 ** database handle. 9489 ** 9490 ** Session objects created using this function should be deleted using the 9491 ** [sqlite3session_delete()] function before the database handle that they 9492 ** are attached to is itself closed. If the database handle is closed before 9493 ** the session object is deleted, then the results of calling any session 9494 ** module function, including [sqlite3session_delete()] on the session object 9495 ** are undefined. 9496 ** 9497 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it 9498 ** is not possible for an application to register a pre-update hook on a 9499 ** database handle that has one or more session objects attached. Nor is 9500 ** it possible to create a session object attached to a database handle for 9501 ** which a pre-update hook is already defined. The results of attempting 9502 ** either of these things are undefined. 9503 ** 9504 ** The session object will be used to create changesets for tables in 9505 ** database zDb, where zDb is either "main", or "temp", or the name of an 9506 ** attached database. It is not an error if database zDb is not attached 9507 ** to the database when the session object is created. 9508 */ 9509 SQLITE_API int sqlite3session_create( 9510 sqlite3 *db, /* Database handle */ 9511 const char *zDb, /* Name of db (e.g. "main") */ 9512 sqlite3_session **ppSession /* OUT: New session object */ 9513 ); 9514 9515 /* 9516 ** CAPI3REF: Delete A Session Object 9517 ** DESTRUCTOR: sqlite3_session 9518 ** 9519 ** Delete a session object previously allocated using 9520 ** [sqlite3session_create()]. Once a session object has been deleted, the 9521 ** results of attempting to use pSession with any other session module 9522 ** function are undefined. 9523 ** 9524 ** Session objects must be deleted before the database handle to which they 9525 ** are attached is closed. Refer to the documentation for 9526 ** [sqlite3session_create()] for details. 9527 */ 9528 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 9529 9530 9531 /* 9532 ** CAPI3REF: Enable Or Disable A Session Object 9533 ** METHOD: sqlite3_session 9534 ** 9535 ** Enable or disable the recording of changes by a session object. When 9536 ** enabled, a session object records changes made to the database. When 9537 ** disabled - it does not. A newly created session object is enabled. 9538 ** Refer to the documentation for [sqlite3session_changeset()] for further 9539 ** details regarding how enabling and disabling a session object affects 9540 ** the eventual changesets. 9541 ** 9542 ** Passing zero to this function disables the session. Passing a value 9543 ** greater than zero enables it. Passing a value less than zero is a 9544 ** no-op, and may be used to query the current state of the session. 9545 ** 9546 ** The return value indicates the final state of the session object: 0 if 9547 ** the session is disabled, or 1 if it is enabled. 9548 */ 9549 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 9550 9551 /* 9552 ** CAPI3REF: Set Or Clear the Indirect Change Flag 9553 ** METHOD: sqlite3_session 9554 ** 9555 ** Each change recorded by a session object is marked as either direct or 9556 ** indirect. A change is marked as indirect if either: 9557 ** 9558 ** <ul> 9559 ** <li> The session object "indirect" flag is set when the change is 9560 ** made, or 9561 ** <li> The change is made by an SQL trigger or foreign key action 9562 ** instead of directly as a result of a users SQL statement. 9563 ** </ul> 9564 ** 9565 ** If a single row is affected by more than one operation within a session, 9566 ** then the change is considered indirect if all operations meet the criteria 9567 ** for an indirect change above, or direct otherwise. 9568 ** 9569 ** This function is used to set, clear or query the session object indirect 9570 ** flag. If the second argument passed to this function is zero, then the 9571 ** indirect flag is cleared. If it is greater than zero, the indirect flag 9572 ** is set. Passing a value less than zero does not modify the current value 9573 ** of the indirect flag, and may be used to query the current state of the 9574 ** indirect flag for the specified session object. 9575 ** 9576 ** The return value indicates the final state of the indirect flag: 0 if 9577 ** it is clear, or 1 if it is set. 9578 */ 9579 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 9580 9581 /* 9582 ** CAPI3REF: Attach A Table To A Session Object 9583 ** METHOD: sqlite3_session 9584 ** 9585 ** If argument zTab is not NULL, then it is the name of a table to attach 9586 ** to the session object passed as the first argument. All subsequent changes 9587 ** made to the table while the session object is enabled will be recorded. See 9588 ** documentation for [sqlite3session_changeset()] for further details. 9589 ** 9590 ** Or, if argument zTab is NULL, then changes are recorded for all tables 9591 ** in the database. If additional tables are added to the database (by 9592 ** executing "CREATE TABLE" statements) after this call is made, changes for 9593 ** the new tables are also recorded. 9594 ** 9595 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 9596 ** defined as part of their CREATE TABLE statement. It does not matter if the 9597 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 9598 ** KEY may consist of a single column, or may be a composite key. 9599 ** 9600 ** It is not an error if the named table does not exist in the database. Nor 9601 ** is it an error if the named table does not have a PRIMARY KEY. However, 9602 ** no changes will be recorded in either of these scenarios. 9603 ** 9604 ** Changes are not recorded for individual rows that have NULL values stored 9605 ** in one or more of their PRIMARY KEY columns. 9606 ** 9607 ** SQLITE_OK is returned if the call completes without error. Or, if an error 9608 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 9609 ** 9610 ** <h3>Special sqlite_stat1 Handling</h3> 9611 ** 9612 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 9613 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 9614 ** <pre> 9615 ** CREATE TABLE sqlite_stat1(tbl,idx,stat) 9616 ** </pre> 9617 ** 9618 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 9619 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 9620 ** are recorded for rows for which (idx IS NULL) is true. However, for such 9621 ** rows a zero-length blob (SQL value X'') is stored in the changeset or 9622 ** patchset instead of a NULL value. This allows such changesets to be 9623 ** manipulated by legacy implementations of sqlite3changeset_invert(), 9624 ** concat() and similar. 9625 ** 9626 ** The sqlite3changeset_apply() function automatically converts the 9627 ** zero-length blob back to a NULL value when updating the sqlite_stat1 9628 ** table. However, if the application calls sqlite3changeset_new(), 9629 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 9630 ** iterator directly (including on a changeset iterator passed to a 9631 ** conflict-handler callback) then the X'' value is returned. The application 9632 ** must translate X'' to NULL itself if required. 9633 ** 9634 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture 9635 ** changes made to the sqlite_stat1 table. Legacy versions of the 9636 ** sqlite3changeset_apply() function silently ignore any modifications to the 9637 ** sqlite_stat1 table that are part of a changeset or patchset. 9638 */ 9639 SQLITE_API int sqlite3session_attach( 9640 sqlite3_session *pSession, /* Session object */ 9641 const char *zTab /* Table name */ 9642 ); 9643 9644 /* 9645 ** CAPI3REF: Set a table filter on a Session Object. 9646 ** METHOD: sqlite3_session 9647 ** 9648 ** The second argument (xFilter) is the "filter callback". For changes to rows 9649 ** in tables that are not attached to the Session object, the filter is called 9650 ** to determine whether changes to the table's rows should be tracked or not. 9651 ** If xFilter returns 0, changes is not tracked. Note that once a table is 9652 ** attached, xFilter will not be called again. 9653 */ 9654 SQLITE_API void sqlite3session_table_filter( 9655 sqlite3_session *pSession, /* Session object */ 9656 int(*xFilter)( 9657 void *pCtx, /* Copy of third arg to _filter_table() */ 9658 const char *zTab /* Table name */ 9659 ), 9660 void *pCtx /* First argument passed to xFilter */ 9661 ); 9662 9663 /* 9664 ** CAPI3REF: Generate A Changeset From A Session Object 9665 ** METHOD: sqlite3_session 9666 ** 9667 ** Obtain a changeset containing changes to the tables attached to the 9668 ** session object passed as the first argument. If successful, 9669 ** set *ppChangeset to point to a buffer containing the changeset 9670 ** and *pnChangeset to the size of the changeset in bytes before returning 9671 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 9672 ** zero and return an SQLite error code. 9673 ** 9674 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 9675 ** each representing a change to a single row of an attached table. An INSERT 9676 ** change contains the values of each field of a new database row. A DELETE 9677 ** contains the original values of each field of a deleted database row. An 9678 ** UPDATE change contains the original values of each field of an updated 9679 ** database row along with the updated values for each updated non-primary-key 9680 ** column. It is not possible for an UPDATE change to represent a change that 9681 ** modifies the values of primary key columns. If such a change is made, it 9682 ** is represented in a changeset as a DELETE followed by an INSERT. 9683 ** 9684 ** Changes are not recorded for rows that have NULL values stored in one or 9685 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 9686 ** no corresponding change is present in the changesets returned by this 9687 ** function. If an existing row with one or more NULL values stored in 9688 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 9689 ** only an INSERT is appears in the changeset. Similarly, if an existing row 9690 ** with non-NULL PRIMARY KEY values is updated so that one or more of its 9691 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 9692 ** DELETE change only. 9693 ** 9694 ** The contents of a changeset may be traversed using an iterator created 9695 ** using the [sqlite3changeset_start()] API. A changeset may be applied to 9696 ** a database with a compatible schema using the [sqlite3changeset_apply()] 9697 ** API. 9698 ** 9699 ** Within a changeset generated by this function, all changes related to a 9700 ** single table are grouped together. In other words, when iterating through 9701 ** a changeset or when applying a changeset to a database, all changes related 9702 ** to a single table are processed before moving on to the next table. Tables 9703 ** are sorted in the same order in which they were attached (or auto-attached) 9704 ** to the sqlite3_session object. The order in which the changes related to 9705 ** a single table are stored is undefined. 9706 ** 9707 ** Following a successful call to this function, it is the responsibility of 9708 ** the caller to eventually free the buffer that *ppChangeset points to using 9709 ** [sqlite3_free()]. 9710 ** 9711 ** <h3>Changeset Generation</h3> 9712 ** 9713 ** Once a table has been attached to a session object, the session object 9714 ** records the primary key values of all new rows inserted into the table. 9715 ** It also records the original primary key and other column values of any 9716 ** deleted or updated rows. For each unique primary key value, data is only 9717 ** recorded once - the first time a row with said primary key is inserted, 9718 ** updated or deleted in the lifetime of the session. 9719 ** 9720 ** There is one exception to the previous paragraph: when a row is inserted, 9721 ** updated or deleted, if one or more of its primary key columns contain a 9722 ** NULL value, no record of the change is made. 9723 ** 9724 ** The session object therefore accumulates two types of records - those 9725 ** that consist of primary key values only (created when the user inserts 9726 ** a new record) and those that consist of the primary key values and the 9727 ** original values of other table columns (created when the users deletes 9728 ** or updates a record). 9729 ** 9730 ** When this function is called, the requested changeset is created using 9731 ** both the accumulated records and the current contents of the database 9732 ** file. Specifically: 9733 ** 9734 ** <ul> 9735 ** <li> For each record generated by an insert, the database is queried 9736 ** for a row with a matching primary key. If one is found, an INSERT 9737 ** change is added to the changeset. If no such row is found, no change 9738 ** is added to the changeset. 9739 ** 9740 ** <li> For each record generated by an update or delete, the database is 9741 ** queried for a row with a matching primary key. If such a row is 9742 ** found and one or more of the non-primary key fields have been 9743 ** modified from their original values, an UPDATE change is added to 9744 ** the changeset. Or, if no such row is found in the table, a DELETE 9745 ** change is added to the changeset. If there is a row with a matching 9746 ** primary key in the database, but all fields contain their original 9747 ** values, no change is added to the changeset. 9748 ** </ul> 9749 ** 9750 ** This means, amongst other things, that if a row is inserted and then later 9751 ** deleted while a session object is active, neither the insert nor the delete 9752 ** will be present in the changeset. Or if a row is deleted and then later a 9753 ** row with the same primary key values inserted while a session object is 9754 ** active, the resulting changeset will contain an UPDATE change instead of 9755 ** a DELETE and an INSERT. 9756 ** 9757 ** When a session object is disabled (see the [sqlite3session_enable()] API), 9758 ** it does not accumulate records when rows are inserted, updated or deleted. 9759 ** This may appear to have some counter-intuitive effects if a single row 9760 ** is written to more than once during a session. For example, if a row 9761 ** is inserted while a session object is enabled, then later deleted while 9762 ** the same session object is disabled, no INSERT record will appear in the 9763 ** changeset, even though the delete took place while the session was disabled. 9764 ** Or, if one field of a row is updated while a session is disabled, and 9765 ** another field of the same row is updated while the session is enabled, the 9766 ** resulting changeset will contain an UPDATE change that updates both fields. 9767 */ 9768 SQLITE_API int sqlite3session_changeset( 9769 sqlite3_session *pSession, /* Session object */ 9770 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 9771 void **ppChangeset /* OUT: Buffer containing changeset */ 9772 ); 9773 9774 /* 9775 ** CAPI3REF: Load The Difference Between Tables Into A Session 9776 ** METHOD: sqlite3_session 9777 ** 9778 ** If it is not already attached to the session object passed as the first 9779 ** argument, this function attaches table zTbl in the same manner as the 9780 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it 9781 ** does not have a primary key, this function is a no-op (but does not return 9782 ** an error). 9783 ** 9784 ** Argument zFromDb must be the name of a database ("main", "temp" etc.) 9785 ** attached to the same database handle as the session object that contains 9786 ** a table compatible with the table attached to the session by this function. 9787 ** A table is considered compatible if it: 9788 ** 9789 ** <ul> 9790 ** <li> Has the same name, 9791 ** <li> Has the same set of columns declared in the same order, and 9792 ** <li> Has the same PRIMARY KEY definition. 9793 ** </ul> 9794 ** 9795 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 9796 ** are compatible but do not have any PRIMARY KEY columns, it is not an error 9797 ** but no changes are added to the session object. As with other session 9798 ** APIs, tables without PRIMARY KEYs are simply ignored. 9799 ** 9800 ** This function adds a set of changes to the session object that could be 9801 ** used to update the table in database zFrom (call this the "from-table") 9802 ** so that its content is the same as the table attached to the session 9803 ** object (call this the "to-table"). Specifically: 9804 ** 9805 ** <ul> 9806 ** <li> For each row (primary key) that exists in the to-table but not in 9807 ** the from-table, an INSERT record is added to the session object. 9808 ** 9809 ** <li> For each row (primary key) that exists in the to-table but not in 9810 ** the from-table, a DELETE record is added to the session object. 9811 ** 9812 ** <li> For each row (primary key) that exists in both tables, but features 9813 ** different non-PK values in each, an UPDATE record is added to the 9814 ** session. 9815 ** </ul> 9816 ** 9817 ** To clarify, if this function is called and then a changeset constructed 9818 ** using [sqlite3session_changeset()], then after applying that changeset to 9819 ** database zFrom the contents of the two compatible tables would be 9820 ** identical. 9821 ** 9822 ** It an error if database zFrom does not exist or does not contain the 9823 ** required compatible table. 9824 ** 9825 ** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite 9826 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 9827 ** may be set to point to a buffer containing an English language error 9828 ** message. It is the responsibility of the caller to free this buffer using 9829 ** sqlite3_free(). 9830 */ 9831 SQLITE_API int sqlite3session_diff( 9832 sqlite3_session *pSession, 9833 const char *zFromDb, 9834 const char *zTbl, 9835 char **pzErrMsg 9836 ); 9837 9838 9839 /* 9840 ** CAPI3REF: Generate A Patchset From A Session Object 9841 ** METHOD: sqlite3_session 9842 ** 9843 ** The differences between a patchset and a changeset are that: 9844 ** 9845 ** <ul> 9846 ** <li> DELETE records consist of the primary key fields only. The 9847 ** original values of other fields are omitted. 9848 ** <li> The original values of any modified fields are omitted from 9849 ** UPDATE records. 9850 ** </ul> 9851 ** 9852 ** A patchset blob may be used with up to date versions of all 9853 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 9854 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 9855 ** attempting to use a patchset blob with old versions of the 9856 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 9857 ** 9858 ** Because the non-primary key "old.*" fields are omitted, no 9859 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 9860 ** is passed to the sqlite3changeset_apply() API. Other conflict types work 9861 ** in the same way as for changesets. 9862 ** 9863 ** Changes within a patchset are ordered in the same way as for changesets 9864 ** generated by the sqlite3session_changeset() function (i.e. all changes for 9865 ** a single table are grouped together, tables appear in the order in which 9866 ** they were attached to the session object). 9867 */ 9868 SQLITE_API int sqlite3session_patchset( 9869 sqlite3_session *pSession, /* Session object */ 9870 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 9871 void **ppPatchset /* OUT: Buffer containing patchset */ 9872 ); 9873 9874 /* 9875 ** CAPI3REF: Test if a changeset has recorded any changes. 9876 ** 9877 ** Return non-zero if no changes to attached tables have been recorded by 9878 ** the session object passed as the first argument. Otherwise, if one or 9879 ** more changes have been recorded, return zero. 9880 ** 9881 ** Even if this function returns zero, it is possible that calling 9882 ** [sqlite3session_changeset()] on the session handle may still return a 9883 ** changeset that contains no changes. This can happen when a row in 9884 ** an attached table is modified and then later on the original values 9885 ** are restored. However, if this function returns non-zero, then it is 9886 ** guaranteed that a call to sqlite3session_changeset() will return a 9887 ** changeset containing zero changes. 9888 */ 9889 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 9890 9891 /* 9892 ** CAPI3REF: Create An Iterator To Traverse A Changeset 9893 ** CONSTRUCTOR: sqlite3_changeset_iter 9894 ** 9895 ** Create an iterator used to iterate through the contents of a changeset. 9896 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK 9897 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an 9898 ** SQLite error code is returned. 9899 ** 9900 ** The following functions can be used to advance and query a changeset 9901 ** iterator created by this function: 9902 ** 9903 ** <ul> 9904 ** <li> [sqlite3changeset_next()] 9905 ** <li> [sqlite3changeset_op()] 9906 ** <li> [sqlite3changeset_new()] 9907 ** <li> [sqlite3changeset_old()] 9908 ** </ul> 9909 ** 9910 ** It is the responsibility of the caller to eventually destroy the iterator 9911 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 9912 ** changeset (pChangeset) must remain valid until after the iterator is 9913 ** destroyed. 9914 ** 9915 ** Assuming the changeset blob was created by one of the 9916 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 9917 ** [sqlite3changeset_invert()] functions, all changes within the changeset 9918 ** that apply to a single table are grouped together. This means that when 9919 ** an application iterates through a changeset using an iterator created by 9920 ** this function, all changes that relate to a single table are visited 9921 ** consecutively. There is no chance that the iterator will visit a change 9922 ** the applies to table X, then one for table Y, and then later on visit 9923 ** another change for table X. 9924 ** 9925 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 9926 ** may be modified by passing a combination of 9927 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 9928 ** 9929 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 9930 ** and therefore subject to change. 9931 */ 9932 SQLITE_API int sqlite3changeset_start( 9933 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9934 int nChangeset, /* Size of changeset blob in bytes */ 9935 void *pChangeset /* Pointer to blob containing changeset */ 9936 ); 9937 SQLITE_API int sqlite3changeset_start_v2( 9938 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 9939 int nChangeset, /* Size of changeset blob in bytes */ 9940 void *pChangeset, /* Pointer to blob containing changeset */ 9941 int flags /* SESSION_CHANGESETSTART_* flags */ 9942 ); 9943 9944 /* 9945 ** CAPI3REF: Flags for sqlite3changeset_start_v2 9946 ** 9947 ** The following flags may passed via the 4th parameter to 9948 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 9949 ** 9950 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 9951 ** Invert the changeset while iterating through it. This is equivalent to 9952 ** inverting a changeset using sqlite3changeset_invert() before applying it. 9953 ** It is an error to specify this flag with a patchset. 9954 */ 9955 #define SQLITE_CHANGESETSTART_INVERT 0x0002 9956 9957 9958 /* 9959 ** CAPI3REF: Advance A Changeset Iterator 9960 ** METHOD: sqlite3_changeset_iter 9961 ** 9962 ** This function may only be used with iterators created by function 9963 ** [sqlite3changeset_start()]. If it is called on an iterator passed to 9964 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 9965 ** is returned and the call has no effect. 9966 ** 9967 ** Immediately after an iterator is created by sqlite3changeset_start(), it 9968 ** does not point to any change in the changeset. Assuming the changeset 9969 ** is not empty, the first call to this function advances the iterator to 9970 ** point to the first change in the changeset. Each subsequent call advances 9971 ** the iterator to point to the next change in the changeset (if any). If 9972 ** no error occurs and the iterator points to a valid change after a call 9973 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 9974 ** Otherwise, if all changes in the changeset have already been visited, 9975 ** SQLITE_DONE is returned. 9976 ** 9977 ** If an error occurs, an SQLite error code is returned. Possible error 9978 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 9979 ** SQLITE_NOMEM. 9980 */ 9981 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 9982 9983 /* 9984 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 9985 ** METHOD: sqlite3_changeset_iter 9986 ** 9987 ** The pIter argument passed to this function may either be an iterator 9988 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 9989 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 9990 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 9991 ** is not the case, this function returns [SQLITE_MISUSE]. 9992 ** 9993 ** If argument pzTab is not NULL, then *pzTab is set to point to a 9994 ** nul-terminated utf-8 encoded string containing the name of the table 9995 ** affected by the current change. The buffer remains valid until either 9996 ** sqlite3changeset_next() is called on the iterator or until the 9997 ** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 9998 ** set to the number of columns in the table affected by the change. If 9999 ** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change 10000 ** is an indirect change, or false (0) otherwise. See the documentation for 10001 ** [sqlite3session_indirect()] for a description of direct and indirect 10002 ** changes. Finally, if pOp is not NULL, then *pOp is set to one of 10003 ** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 10004 ** type of change that the iterator currently points to. 10005 ** 10006 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an 10007 ** SQLite error code is returned. The values of the output variables may not 10008 ** be trusted in this case. 10009 */ 10010 SQLITE_API int sqlite3changeset_op( 10011 sqlite3_changeset_iter *pIter, /* Iterator object */ 10012 const char **pzTab, /* OUT: Pointer to table name */ 10013 int *pnCol, /* OUT: Number of columns in table */ 10014 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 10015 int *pbIndirect /* OUT: True for an 'indirect' change */ 10016 ); 10017 10018 /* 10019 ** CAPI3REF: Obtain The Primary Key Definition Of A Table 10020 ** METHOD: sqlite3_changeset_iter 10021 ** 10022 ** For each modified table, a changeset includes the following: 10023 ** 10024 ** <ul> 10025 ** <li> The number of columns in the table, and 10026 ** <li> Which of those columns make up the tables PRIMARY KEY. 10027 ** </ul> 10028 ** 10029 ** This function is used to find which columns comprise the PRIMARY KEY of 10030 ** the table modified by the change that iterator pIter currently points to. 10031 ** If successful, *pabPK is set to point to an array of nCol entries, where 10032 ** nCol is the number of columns in the table. Elements of *pabPK are set to 10033 ** 0x01 if the corresponding column is part of the tables primary key, or 10034 ** 0x00 if it is not. 10035 ** 10036 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns 10037 ** in the table. 10038 ** 10039 ** If this function is called when the iterator does not point to a valid 10040 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 10041 ** SQLITE_OK is returned and the output variables populated as described 10042 ** above. 10043 */ 10044 SQLITE_API int sqlite3changeset_pk( 10045 sqlite3_changeset_iter *pIter, /* Iterator object */ 10046 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 10047 int *pnCol /* OUT: Number of entries in output array */ 10048 ); 10049 10050 /* 10051 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator 10052 ** METHOD: sqlite3_changeset_iter 10053 ** 10054 ** The pIter argument passed to this function may either be an iterator 10055 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10056 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10057 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10058 ** Furthermore, it may only be called if the type of change that the iterator 10059 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 10060 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10061 ** 10062 ** Argument iVal must be greater than or equal to 0, and less than the number 10063 ** of columns in the table affected by the current change. Otherwise, 10064 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10065 ** 10066 ** If successful, this function sets *ppValue to point to a protected 10067 ** sqlite3_value object containing the iVal'th value from the vector of 10068 ** original row values stored as part of the UPDATE or DELETE change and 10069 ** returns SQLITE_OK. The name of the function comes from the fact that this 10070 ** is similar to the "old.*" columns available to update or delete triggers. 10071 ** 10072 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10073 ** is returned and *ppValue is set to NULL. 10074 */ 10075 SQLITE_API int sqlite3changeset_old( 10076 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10077 int iVal, /* Column number */ 10078 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 10079 ); 10080 10081 /* 10082 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator 10083 ** METHOD: sqlite3_changeset_iter 10084 ** 10085 ** The pIter argument passed to this function may either be an iterator 10086 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 10087 ** created by [sqlite3changeset_start()]. In the latter case, the most recent 10088 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 10089 ** Furthermore, it may only be called if the type of change that the iterator 10090 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 10091 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 10092 ** 10093 ** Argument iVal must be greater than or equal to 0, and less than the number 10094 ** of columns in the table affected by the current change. Otherwise, 10095 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10096 ** 10097 ** If successful, this function sets *ppValue to point to a protected 10098 ** sqlite3_value object containing the iVal'th value from the vector of 10099 ** new row values stored as part of the UPDATE or INSERT change and 10100 ** returns SQLITE_OK. If the change is an UPDATE and does not include 10101 ** a new value for the requested column, *ppValue is set to NULL and 10102 ** SQLITE_OK returned. The name of the function comes from the fact that 10103 ** this is similar to the "new.*" columns available to update or delete 10104 ** triggers. 10105 ** 10106 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10107 ** is returned and *ppValue is set to NULL. 10108 */ 10109 SQLITE_API int sqlite3changeset_new( 10110 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10111 int iVal, /* Column number */ 10112 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 10113 ); 10114 10115 /* 10116 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 10117 ** METHOD: sqlite3_changeset_iter 10118 ** 10119 ** This function should only be used with iterator objects passed to a 10120 ** conflict-handler callback by [sqlite3changeset_apply()] with either 10121 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 10122 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 10123 ** is set to NULL. 10124 ** 10125 ** Argument iVal must be greater than or equal to 0, and less than the number 10126 ** of columns in the table affected by the current change. Otherwise, 10127 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 10128 ** 10129 ** If successful, this function sets *ppValue to point to a protected 10130 ** sqlite3_value object containing the iVal'th value from the 10131 ** "conflicting row" associated with the current conflict-handler callback 10132 ** and returns SQLITE_OK. 10133 ** 10134 ** If some other error occurs (e.g. an OOM condition), an SQLite error code 10135 ** is returned and *ppValue is set to NULL. 10136 */ 10137 SQLITE_API int sqlite3changeset_conflict( 10138 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10139 int iVal, /* Column number */ 10140 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 10141 ); 10142 10143 /* 10144 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 10145 ** METHOD: sqlite3_changeset_iter 10146 ** 10147 ** This function may only be called with an iterator passed to an 10148 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 10149 ** it sets the output variable to the total number of known foreign key 10150 ** violations in the destination database and returns SQLITE_OK. 10151 ** 10152 ** In all other cases this function returns SQLITE_MISUSE. 10153 */ 10154 SQLITE_API int sqlite3changeset_fk_conflicts( 10155 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 10156 int *pnOut /* OUT: Number of FK violations */ 10157 ); 10158 10159 10160 /* 10161 ** CAPI3REF: Finalize A Changeset Iterator 10162 ** METHOD: sqlite3_changeset_iter 10163 ** 10164 ** This function is used to finalize an iterator allocated with 10165 ** [sqlite3changeset_start()]. 10166 ** 10167 ** This function should only be called on iterators created using the 10168 ** [sqlite3changeset_start()] function. If an application calls this 10169 ** function with an iterator passed to a conflict-handler by 10170 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 10171 ** call has no effect. 10172 ** 10173 ** If an error was encountered within a call to an sqlite3changeset_xxx() 10174 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 10175 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 10176 ** to that error is returned by this function. Otherwise, SQLITE_OK is 10177 ** returned. This is to allow the following pattern (pseudo-code): 10178 ** 10179 ** <pre> 10180 ** sqlite3changeset_start(); 10181 ** while( SQLITE_ROW==sqlite3changeset_next() ){ 10182 ** // Do something with change. 10183 ** } 10184 ** rc = sqlite3changeset_finalize(); 10185 ** if( rc!=SQLITE_OK ){ 10186 ** // An error has occurred 10187 ** } 10188 ** </pre> 10189 */ 10190 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 10191 10192 /* 10193 ** CAPI3REF: Invert A Changeset 10194 ** 10195 ** This function is used to "invert" a changeset object. Applying an inverted 10196 ** changeset to a database reverses the effects of applying the uninverted 10197 ** changeset. Specifically: 10198 ** 10199 ** <ul> 10200 ** <li> Each DELETE change is changed to an INSERT, and 10201 ** <li> Each INSERT change is changed to a DELETE, and 10202 ** <li> For each UPDATE change, the old.* and new.* values are exchanged. 10203 ** </ul> 10204 ** 10205 ** This function does not change the order in which changes appear within 10206 ** the changeset. It merely reverses the sense of each individual change. 10207 ** 10208 ** If successful, a pointer to a buffer containing the inverted changeset 10209 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 10210 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 10211 ** zeroed and an SQLite error code returned. 10212 ** 10213 ** It is the responsibility of the caller to eventually call sqlite3_free() 10214 ** on the *ppOut pointer to free the buffer allocation following a successful 10215 ** call to this function. 10216 ** 10217 ** WARNING/TODO: This function currently assumes that the input is a valid 10218 ** changeset. If it is not, the results are undefined. 10219 */ 10220 SQLITE_API int sqlite3changeset_invert( 10221 int nIn, const void *pIn, /* Input changeset */ 10222 int *pnOut, void **ppOut /* OUT: Inverse of input */ 10223 ); 10224 10225 /* 10226 ** CAPI3REF: Concatenate Two Changeset Objects 10227 ** 10228 ** This function is used to concatenate two changesets, A and B, into a 10229 ** single changeset. The result is a changeset equivalent to applying 10230 ** changeset A followed by changeset B. 10231 ** 10232 ** This function combines the two input changesets using an 10233 ** sqlite3_changegroup object. Calling it produces similar results as the 10234 ** following code fragment: 10235 ** 10236 ** <pre> 10237 ** sqlite3_changegroup *pGrp; 10238 ** rc = sqlite3_changegroup_new(&pGrp); 10239 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 10240 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 10241 ** if( rc==SQLITE_OK ){ 10242 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 10243 ** }else{ 10244 ** *ppOut = 0; 10245 ** *pnOut = 0; 10246 ** } 10247 ** </pre> 10248 ** 10249 ** Refer to the sqlite3_changegroup documentation below for details. 10250 */ 10251 SQLITE_API int sqlite3changeset_concat( 10252 int nA, /* Number of bytes in buffer pA */ 10253 void *pA, /* Pointer to buffer containing changeset A */ 10254 int nB, /* Number of bytes in buffer pB */ 10255 void *pB, /* Pointer to buffer containing changeset B */ 10256 int *pnOut, /* OUT: Number of bytes in output changeset */ 10257 void **ppOut /* OUT: Buffer containing output changeset */ 10258 ); 10259 10260 10261 /* 10262 ** CAPI3REF: Changegroup Handle 10263 ** 10264 ** A changegroup is an object used to combine two or more 10265 ** [changesets] or [patchsets] 10266 */ 10267 typedef struct sqlite3_changegroup sqlite3_changegroup; 10268 10269 /* 10270 ** CAPI3REF: Create A New Changegroup Object 10271 ** CONSTRUCTOR: sqlite3_changegroup 10272 ** 10273 ** An sqlite3_changegroup object is used to combine two or more changesets 10274 ** (or patchsets) into a single changeset (or patchset). A single changegroup 10275 ** object may combine changesets or patchsets, but not both. The output is 10276 ** always in the same format as the input. 10277 ** 10278 ** If successful, this function returns SQLITE_OK and populates (*pp) with 10279 ** a pointer to a new sqlite3_changegroup object before returning. The caller 10280 ** should eventually free the returned object using a call to 10281 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 10282 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 10283 ** 10284 ** The usual usage pattern for an sqlite3_changegroup object is as follows: 10285 ** 10286 ** <ul> 10287 ** <li> It is created using a call to sqlite3changegroup_new(). 10288 ** 10289 ** <li> Zero or more changesets (or patchsets) are added to the object 10290 ** by calling sqlite3changegroup_add(). 10291 ** 10292 ** <li> The result of combining all input changesets together is obtained 10293 ** by the application via a call to sqlite3changegroup_output(). 10294 ** 10295 ** <li> The object is deleted using a call to sqlite3changegroup_delete(). 10296 ** </ul> 10297 ** 10298 ** Any number of calls to add() and output() may be made between the calls to 10299 ** new() and delete(), and in any order. 10300 ** 10301 ** As well as the regular sqlite3changegroup_add() and 10302 ** sqlite3changegroup_output() functions, also available are the streaming 10303 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 10304 */ 10305 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 10306 10307 /* 10308 ** CAPI3REF: Add A Changeset To A Changegroup 10309 ** METHOD: sqlite3_changegroup 10310 ** 10311 ** Add all changes within the changeset (or patchset) in buffer pData (size 10312 ** nData bytes) to the changegroup. 10313 ** 10314 ** If the buffer contains a patchset, then all prior calls to this function 10315 ** on the same changegroup object must also have specified patchsets. Or, if 10316 ** the buffer contains a changeset, so must have the earlier calls to this 10317 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added 10318 ** to the changegroup. 10319 ** 10320 ** Rows within the changeset and changegroup are identified by the values in 10321 ** their PRIMARY KEY columns. A change in the changeset is considered to 10322 ** apply to the same row as a change already present in the changegroup if 10323 ** the two rows have the same primary key. 10324 ** 10325 ** Changes to rows that do not already appear in the changegroup are 10326 ** simply copied into it. Or, if both the new changeset and the changegroup 10327 ** contain changes that apply to a single row, the final contents of the 10328 ** changegroup depends on the type of each change, as follows: 10329 ** 10330 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10331 ** <tr><th style="white-space:pre">Existing Change </th> 10332 ** <th style="white-space:pre">New Change </th> 10333 ** <th>Output Change 10334 ** <tr><td>INSERT <td>INSERT <td> 10335 ** The new change is ignored. This case does not occur if the new 10336 ** changeset was recorded immediately after the changesets already 10337 ** added to the changegroup. 10338 ** <tr><td>INSERT <td>UPDATE <td> 10339 ** The INSERT change remains in the changegroup. The values in the 10340 ** INSERT change are modified as if the row was inserted by the 10341 ** existing change and then updated according to the new change. 10342 ** <tr><td>INSERT <td>DELETE <td> 10343 ** The existing INSERT is removed from the changegroup. The DELETE is 10344 ** not added. 10345 ** <tr><td>UPDATE <td>INSERT <td> 10346 ** The new change is ignored. This case does not occur if the new 10347 ** changeset was recorded immediately after the changesets already 10348 ** added to the changegroup. 10349 ** <tr><td>UPDATE <td>UPDATE <td> 10350 ** The existing UPDATE remains within the changegroup. It is amended 10351 ** so that the accompanying values are as if the row was updated once 10352 ** by the existing change and then again by the new change. 10353 ** <tr><td>UPDATE <td>DELETE <td> 10354 ** The existing UPDATE is replaced by the new DELETE within the 10355 ** changegroup. 10356 ** <tr><td>DELETE <td>INSERT <td> 10357 ** If one or more of the column values in the row inserted by the 10358 ** new change differ from those in the row deleted by the existing 10359 ** change, the existing DELETE is replaced by an UPDATE within the 10360 ** changegroup. Otherwise, if the inserted row is exactly the same 10361 ** as the deleted row, the existing DELETE is simply discarded. 10362 ** <tr><td>DELETE <td>UPDATE <td> 10363 ** The new change is ignored. This case does not occur if the new 10364 ** changeset was recorded immediately after the changesets already 10365 ** added to the changegroup. 10366 ** <tr><td>DELETE <td>DELETE <td> 10367 ** The new change is ignored. This case does not occur if the new 10368 ** changeset was recorded immediately after the changesets already 10369 ** added to the changegroup. 10370 ** </table> 10371 ** 10372 ** If the new changeset contains changes to a table that is already present 10373 ** in the changegroup, then the number of columns and the position of the 10374 ** primary key columns for the table must be consistent. If this is not the 10375 ** case, this function fails with SQLITE_SCHEMA. If the input changeset 10376 ** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 10377 ** returned. Or, if an out-of-memory condition occurs during processing, this 10378 ** function returns SQLITE_NOMEM. In all cases, if an error occurs the 10379 ** final contents of the changegroup is undefined. 10380 ** 10381 ** If no error occurs, SQLITE_OK is returned. 10382 */ 10383 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 10384 10385 /* 10386 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup 10387 ** METHOD: sqlite3_changegroup 10388 ** 10389 ** Obtain a buffer containing a changeset (or patchset) representing the 10390 ** current contents of the changegroup. If the inputs to the changegroup 10391 ** were themselves changesets, the output is a changeset. Or, if the 10392 ** inputs were patchsets, the output is also a patchset. 10393 ** 10394 ** As with the output of the sqlite3session_changeset() and 10395 ** sqlite3session_patchset() functions, all changes related to a single 10396 ** table are grouped together in the output of this function. Tables appear 10397 ** in the same order as for the very first changeset added to the changegroup. 10398 ** If the second or subsequent changesets added to the changegroup contain 10399 ** changes for tables that do not appear in the first changeset, they are 10400 ** appended onto the end of the output changeset, again in the order in 10401 ** which they are first encountered. 10402 ** 10403 ** If an error occurs, an SQLite error code is returned and the output 10404 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 10405 ** is returned and the output variables are set to the size of and a 10406 ** pointer to the output buffer, respectively. In this case it is the 10407 ** responsibility of the caller to eventually free the buffer using a 10408 ** call to sqlite3_free(). 10409 */ 10410 SQLITE_API int sqlite3changegroup_output( 10411 sqlite3_changegroup*, 10412 int *pnData, /* OUT: Size of output buffer in bytes */ 10413 void **ppData /* OUT: Pointer to output buffer */ 10414 ); 10415 10416 /* 10417 ** CAPI3REF: Delete A Changegroup Object 10418 ** DESTRUCTOR: sqlite3_changegroup 10419 */ 10420 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 10421 10422 /* 10423 ** CAPI3REF: Apply A Changeset To A Database 10424 ** 10425 ** Apply a changeset or patchset to a database. These functions attempt to 10426 ** update the "main" database attached to handle db with the changes found in 10427 ** the changeset passed via the second and third arguments. 10428 ** 10429 ** The fourth argument (xFilter) passed to these functions is the "filter 10430 ** callback". If it is not NULL, then for each table affected by at least one 10431 ** change in the changeset, the filter callback is invoked with 10432 ** the table name as the second argument, and a copy of the context pointer 10433 ** passed as the sixth argument as the first. If the "filter callback" 10434 ** returns zero, then no attempt is made to apply any changes to the table. 10435 ** Otherwise, if the return value is non-zero or the xFilter argument to 10436 ** is NULL, all changes related to the table are attempted. 10437 ** 10438 ** For each table that is not excluded by the filter callback, this function 10439 ** tests that the target database contains a compatible table. A table is 10440 ** considered compatible if all of the following are true: 10441 ** 10442 ** <ul> 10443 ** <li> The table has the same name as the name recorded in the 10444 ** changeset, and 10445 ** <li> The table has at least as many columns as recorded in the 10446 ** changeset, and 10447 ** <li> The table has primary key columns in the same position as 10448 ** recorded in the changeset. 10449 ** </ul> 10450 ** 10451 ** If there is no compatible table, it is not an error, but none of the 10452 ** changes associated with the table are applied. A warning message is issued 10453 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 10454 ** one such warning is issued for each table in the changeset. 10455 ** 10456 ** For each change for which there is a compatible table, an attempt is made 10457 ** to modify the table contents according to the UPDATE, INSERT or DELETE 10458 ** change. If a change cannot be applied cleanly, the conflict handler 10459 ** function passed as the fifth argument to sqlite3changeset_apply() may be 10460 ** invoked. A description of exactly when the conflict handler is invoked for 10461 ** each type of change is below. 10462 ** 10463 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results 10464 ** of passing anything other than a valid function pointer as the xConflict 10465 ** argument are undefined. 10466 ** 10467 ** Each time the conflict handler function is invoked, it must return one 10468 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 10469 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 10470 ** if the second argument passed to the conflict handler is either 10471 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 10472 ** returns an illegal value, any changes already made are rolled back and 10473 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 10474 ** actions are taken by sqlite3changeset_apply() depending on the value 10475 ** returned by each invocation of the conflict-handler function. Refer to 10476 ** the documentation for the three 10477 ** [SQLITE_CHANGESET_OMIT|available return values] for details. 10478 ** 10479 ** <dl> 10480 ** <dt>DELETE Changes<dd> 10481 ** For each DELETE change, the function checks if the target database 10482 ** contains a row with the same primary key value (or values) as the 10483 ** original row values stored in the changeset. If it does, and the values 10484 ** stored in all non-primary key columns also match the values stored in 10485 ** the changeset the row is deleted from the target database. 10486 ** 10487 ** If a row with matching primary key values is found, but one or more of 10488 ** the non-primary key fields contains a value different from the original 10489 ** row value stored in the changeset, the conflict-handler function is 10490 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 10491 ** database table has more columns than are recorded in the changeset, 10492 ** only the values of those non-primary key fields are compared against 10493 ** the current database contents - any trailing database table columns 10494 ** are ignored. 10495 ** 10496 ** If no row with matching primary key values is found in the database, 10497 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10498 ** passed as the second argument. 10499 ** 10500 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 10501 ** (which can only happen if a foreign key constraint is violated), the 10502 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 10503 ** passed as the second argument. This includes the case where the DELETE 10504 ** operation is attempted because an earlier call to the conflict handler 10505 ** function returned [SQLITE_CHANGESET_REPLACE]. 10506 ** 10507 ** <dt>INSERT Changes<dd> 10508 ** For each INSERT change, an attempt is made to insert the new row into 10509 ** the database. If the changeset row contains fewer fields than the 10510 ** database table, the trailing fields are populated with their default 10511 ** values. 10512 ** 10513 ** If the attempt to insert the row fails because the database already 10514 ** contains a row with the same primary key values, the conflict handler 10515 ** function is invoked with the second argument set to 10516 ** [SQLITE_CHANGESET_CONFLICT]. 10517 ** 10518 ** If the attempt to insert the row fails because of some other constraint 10519 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 10520 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 10521 ** This includes the case where the INSERT operation is re-attempted because 10522 ** an earlier call to the conflict handler function returned 10523 ** [SQLITE_CHANGESET_REPLACE]. 10524 ** 10525 ** <dt>UPDATE Changes<dd> 10526 ** For each UPDATE change, the function checks if the target database 10527 ** contains a row with the same primary key value (or values) as the 10528 ** original row values stored in the changeset. If it does, and the values 10529 ** stored in all modified non-primary key columns also match the values 10530 ** stored in the changeset the row is updated within the target database. 10531 ** 10532 ** If a row with matching primary key values is found, but one or more of 10533 ** the modified non-primary key fields contains a value different from an 10534 ** original row value stored in the changeset, the conflict-handler function 10535 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 10536 ** UPDATE changes only contain values for non-primary key fields that are 10537 ** to be modified, only those fields need to match the original values to 10538 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 10539 ** 10540 ** If no row with matching primary key values is found in the database, 10541 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 10542 ** passed as the second argument. 10543 ** 10544 ** If the UPDATE operation is attempted, but SQLite returns 10545 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 10546 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 10547 ** This includes the case where the UPDATE operation is attempted after 10548 ** an earlier call to the conflict handler function returned 10549 ** [SQLITE_CHANGESET_REPLACE]. 10550 ** </dl> 10551 ** 10552 ** It is safe to execute SQL statements, including those that write to the 10553 ** table that the callback related to, from within the xConflict callback. 10554 ** This can be used to further customize the applications conflict 10555 ** resolution strategy. 10556 ** 10557 ** All changes made by these functions are enclosed in a savepoint transaction. 10558 ** If any other error (aside from a constraint failure when attempting to 10559 ** write to the target database) occurs, then the savepoint transaction is 10560 ** rolled back, restoring the target database to its original state, and an 10561 ** SQLite error code returned. 10562 ** 10563 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 10564 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 10565 ** may set (*ppRebase) to point to a "rebase" that may be used with the 10566 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 10567 ** is set to the size of the buffer in bytes. It is the responsibility of the 10568 ** caller to eventually free any such buffer using sqlite3_free(). The buffer 10569 ** is only allocated and populated if one or more conflicts were encountered 10570 ** while applying the patchset. See comments surrounding the sqlite3_rebaser 10571 ** APIs for further details. 10572 ** 10573 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 10574 ** may be modified by passing a combination of 10575 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 10576 ** 10577 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 10578 ** and therefore subject to change. 10579 */ 10580 SQLITE_API int sqlite3changeset_apply( 10581 sqlite3 *db, /* Apply change to "main" db of this handle */ 10582 int nChangeset, /* Size of changeset in bytes */ 10583 void *pChangeset, /* Changeset blob */ 10584 int(*xFilter)( 10585 void *pCtx, /* Copy of sixth arg to _apply() */ 10586 const char *zTab /* Table name */ 10587 ), 10588 int(*xConflict)( 10589 void *pCtx, /* Copy of sixth arg to _apply() */ 10590 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10591 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10592 ), 10593 void *pCtx /* First argument passed to xConflict */ 10594 ); 10595 SQLITE_API int sqlite3changeset_apply_v2( 10596 sqlite3 *db, /* Apply change to "main" db of this handle */ 10597 int nChangeset, /* Size of changeset in bytes */ 10598 void *pChangeset, /* Changeset blob */ 10599 int(*xFilter)( 10600 void *pCtx, /* Copy of sixth arg to _apply() */ 10601 const char *zTab /* Table name */ 10602 ), 10603 int(*xConflict)( 10604 void *pCtx, /* Copy of sixth arg to _apply() */ 10605 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10606 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10607 ), 10608 void *pCtx, /* First argument passed to xConflict */ 10609 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 10610 int flags /* SESSION_CHANGESETAPPLY_* flags */ 10611 ); 10612 10613 /* 10614 ** CAPI3REF: Flags for sqlite3changeset_apply_v2 10615 ** 10616 ** The following flags may passed via the 9th parameter to 10617 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 10618 ** 10619 ** <dl> 10620 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 10621 ** Usually, the sessions module encloses all operations performed by 10622 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 10623 ** SAVEPOINT is committed if the changeset or patchset is successfully 10624 ** applied, or rolled back if an error occurs. Specifying this flag 10625 ** causes the sessions module to omit this savepoint. In this case, if the 10626 ** caller has an open transaction or savepoint when apply_v2() is called, 10627 ** it may revert the partially applied changeset by rolling it back. 10628 ** 10629 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 10630 ** Invert the changeset before applying it. This is equivalent to inverting 10631 ** a changeset using sqlite3changeset_invert() before applying it. It is 10632 ** an error to specify this flag with a patchset. 10633 */ 10634 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 10635 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002 10636 10637 /* 10638 ** CAPI3REF: Constants Passed To The Conflict Handler 10639 ** 10640 ** Values that may be passed as the second argument to a conflict-handler. 10641 ** 10642 ** <dl> 10643 ** <dt>SQLITE_CHANGESET_DATA<dd> 10644 ** The conflict handler is invoked with CHANGESET_DATA as the second argument 10645 ** when processing a DELETE or UPDATE change if a row with the required 10646 ** PRIMARY KEY fields is present in the database, but one or more other 10647 ** (non primary-key) fields modified by the update do not contain the 10648 ** expected "before" values. 10649 ** 10650 ** The conflicting row, in this case, is the database row with the matching 10651 ** primary key. 10652 ** 10653 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 10654 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 10655 ** argument when processing a DELETE or UPDATE change if a row with the 10656 ** required PRIMARY KEY fields is not present in the database. 10657 ** 10658 ** There is no conflicting row in this case. The results of invoking the 10659 ** sqlite3changeset_conflict() API are undefined. 10660 ** 10661 ** <dt>SQLITE_CHANGESET_CONFLICT<dd> 10662 ** CHANGESET_CONFLICT is passed as the second argument to the conflict 10663 ** handler while processing an INSERT change if the operation would result 10664 ** in duplicate primary key values. 10665 ** 10666 ** The conflicting row in this case is the database row with the matching 10667 ** primary key. 10668 ** 10669 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 10670 ** If foreign key handling is enabled, and applying a changeset leaves the 10671 ** database in a state containing foreign key violations, the conflict 10672 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 10673 ** exactly once before the changeset is committed. If the conflict handler 10674 ** returns CHANGESET_OMIT, the changes, including those that caused the 10675 ** foreign key constraint violation, are committed. Or, if it returns 10676 ** CHANGESET_ABORT, the changeset is rolled back. 10677 ** 10678 ** No current or conflicting row information is provided. The only function 10679 ** it is possible to call on the supplied sqlite3_changeset_iter handle 10680 ** is sqlite3changeset_fk_conflicts(). 10681 ** 10682 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 10683 ** If any other constraint violation occurs while applying a change (i.e. 10684 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 10685 ** invoked with CHANGESET_CONSTRAINT as the second argument. 10686 ** 10687 ** There is no conflicting row in this case. The results of invoking the 10688 ** sqlite3changeset_conflict() API are undefined. 10689 ** 10690 ** </dl> 10691 */ 10692 #define SQLITE_CHANGESET_DATA 1 10693 #define SQLITE_CHANGESET_NOTFOUND 2 10694 #define SQLITE_CHANGESET_CONFLICT 3 10695 #define SQLITE_CHANGESET_CONSTRAINT 4 10696 #define SQLITE_CHANGESET_FOREIGN_KEY 5 10697 10698 /* 10699 ** CAPI3REF: Constants Returned By The Conflict Handler 10700 ** 10701 ** A conflict handler callback must return one of the following three values. 10702 ** 10703 ** <dl> 10704 ** <dt>SQLITE_CHANGESET_OMIT<dd> 10705 ** If a conflict handler returns this value no special action is taken. The 10706 ** change that caused the conflict is not applied. The session module 10707 ** continues to the next change in the changeset. 10708 ** 10709 ** <dt>SQLITE_CHANGESET_REPLACE<dd> 10710 ** This value may only be returned if the second argument to the conflict 10711 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 10712 ** is not the case, any changes applied so far are rolled back and the 10713 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 10714 ** 10715 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 10716 ** handler, then the conflicting row is either updated or deleted, depending 10717 ** on the type of change. 10718 ** 10719 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 10720 ** handler, then the conflicting row is removed from the database and a 10721 ** second attempt to apply the change is made. If this second attempt fails, 10722 ** the original row is restored to the database before continuing. 10723 ** 10724 ** <dt>SQLITE_CHANGESET_ABORT<dd> 10725 ** If this value is returned, any changes applied so far are rolled back 10726 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 10727 ** </dl> 10728 */ 10729 #define SQLITE_CHANGESET_OMIT 0 10730 #define SQLITE_CHANGESET_REPLACE 1 10731 #define SQLITE_CHANGESET_ABORT 2 10732 10733 /* 10734 ** CAPI3REF: Rebasing changesets 10735 ** EXPERIMENTAL 10736 ** 10737 ** Suppose there is a site hosting a database in state S0. And that 10738 ** modifications are made that move that database to state S1 and a 10739 ** changeset recorded (the "local" changeset). Then, a changeset based 10740 ** on S0 is received from another site (the "remote" changeset) and 10741 ** applied to the database. The database is then in state 10742 ** (S1+"remote"), where the exact state depends on any conflict 10743 ** resolution decisions (OMIT or REPLACE) made while applying "remote". 10744 ** Rebasing a changeset is to update it to take those conflict 10745 ** resolution decisions into account, so that the same conflicts 10746 ** do not have to be resolved elsewhere in the network. 10747 ** 10748 ** For example, if both the local and remote changesets contain an 10749 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 10750 ** 10751 ** local: INSERT INTO t1 VALUES(1, 'v1'); 10752 ** remote: INSERT INTO t1 VALUES(1, 'v2'); 10753 ** 10754 ** and the conflict resolution is REPLACE, then the INSERT change is 10755 ** removed from the local changeset (it was overridden). Or, if the 10756 ** conflict resolution was "OMIT", then the local changeset is modified 10757 ** to instead contain: 10758 ** 10759 ** UPDATE t1 SET b = 'v2' WHERE a=1; 10760 ** 10761 ** Changes within the local changeset are rebased as follows: 10762 ** 10763 ** <dl> 10764 ** <dt>Local INSERT<dd> 10765 ** This may only conflict with a remote INSERT. If the conflict 10766 ** resolution was OMIT, then add an UPDATE change to the rebased 10767 ** changeset. Or, if the conflict resolution was REPLACE, add 10768 ** nothing to the rebased changeset. 10769 ** 10770 ** <dt>Local DELETE<dd> 10771 ** This may conflict with a remote UPDATE or DELETE. In both cases the 10772 ** only possible resolution is OMIT. If the remote operation was a 10773 ** DELETE, then add no change to the rebased changeset. If the remote 10774 ** operation was an UPDATE, then the old.* fields of change are updated 10775 ** to reflect the new.* values in the UPDATE. 10776 ** 10777 ** <dt>Local UPDATE<dd> 10778 ** This may conflict with a remote UPDATE or DELETE. If it conflicts 10779 ** with a DELETE, and the conflict resolution was OMIT, then the update 10780 ** is changed into an INSERT. Any undefined values in the new.* record 10781 ** from the update change are filled in using the old.* values from 10782 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 10783 ** the UPDATE change is simply omitted from the rebased changeset. 10784 ** 10785 ** If conflict is with a remote UPDATE and the resolution is OMIT, then 10786 ** the old.* values are rebased using the new.* values in the remote 10787 ** change. Or, if the resolution is REPLACE, then the change is copied 10788 ** into the rebased changeset with updates to columns also updated by 10789 ** the conflicting remote UPDATE removed. If this means no columns would 10790 ** be updated, the change is omitted. 10791 ** </dl> 10792 ** 10793 ** A local change may be rebased against multiple remote changes 10794 ** simultaneously. If a single key is modified by multiple remote 10795 ** changesets, they are combined as follows before the local changeset 10796 ** is rebased: 10797 ** 10798 ** <ul> 10799 ** <li> If there has been one or more REPLACE resolutions on a 10800 ** key, it is rebased according to a REPLACE. 10801 ** 10802 ** <li> If there have been no REPLACE resolutions on a key, then 10803 ** the local changeset is rebased according to the most recent 10804 ** of the OMIT resolutions. 10805 ** </ul> 10806 ** 10807 ** Note that conflict resolutions from multiple remote changesets are 10808 ** combined on a per-field basis, not per-row. This means that in the 10809 ** case of multiple remote UPDATE operations, some fields of a single 10810 ** local change may be rebased for REPLACE while others are rebased for 10811 ** OMIT. 10812 ** 10813 ** In order to rebase a local changeset, the remote changeset must first 10814 ** be applied to the local database using sqlite3changeset_apply_v2() and 10815 ** the buffer of rebase information captured. Then: 10816 ** 10817 ** <ol> 10818 ** <li> An sqlite3_rebaser object is created by calling 10819 ** sqlite3rebaser_create(). 10820 ** <li> The new object is configured with the rebase buffer obtained from 10821 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 10822 ** If the local changeset is to be rebased against multiple remote 10823 ** changesets, then sqlite3rebaser_configure() should be called 10824 ** multiple times, in the same order that the multiple 10825 ** sqlite3changeset_apply_v2() calls were made. 10826 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 10827 ** <li> The sqlite3_rebaser object is deleted by calling 10828 ** sqlite3rebaser_delete(). 10829 ** </ol> 10830 */ 10831 typedef struct sqlite3_rebaser sqlite3_rebaser; 10832 10833 /* 10834 ** CAPI3REF: Create a changeset rebaser object. 10835 ** EXPERIMENTAL 10836 ** 10837 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 10838 ** point to the new object and return SQLITE_OK. Otherwise, if an error 10839 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 10840 ** to NULL. 10841 */ 10842 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 10843 10844 /* 10845 ** CAPI3REF: Configure a changeset rebaser object. 10846 ** EXPERIMENTAL 10847 ** 10848 ** Configure the changeset rebaser object to rebase changesets according 10849 ** to the conflict resolutions described by buffer pRebase (size nRebase 10850 ** bytes), which must have been obtained from a previous call to 10851 ** sqlite3changeset_apply_v2(). 10852 */ 10853 SQLITE_API int sqlite3rebaser_configure( 10854 sqlite3_rebaser*, 10855 int nRebase, const void *pRebase 10856 ); 10857 10858 /* 10859 ** CAPI3REF: Rebase a changeset 10860 ** EXPERIMENTAL 10861 ** 10862 ** Argument pIn must point to a buffer containing a changeset nIn bytes 10863 ** in size. This function allocates and populates a buffer with a copy 10864 ** of the changeset rebased rebased according to the configuration of the 10865 ** rebaser object passed as the first argument. If successful, (*ppOut) 10866 ** is set to point to the new buffer containing the rebased changset and 10867 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 10868 ** responsibility of the caller to eventually free the new buffer using 10869 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 10870 ** are set to zero and an SQLite error code returned. 10871 */ 10872 SQLITE_API int sqlite3rebaser_rebase( 10873 sqlite3_rebaser*, 10874 int nIn, const void *pIn, 10875 int *pnOut, void **ppOut 10876 ); 10877 10878 /* 10879 ** CAPI3REF: Delete a changeset rebaser object. 10880 ** EXPERIMENTAL 10881 ** 10882 ** Delete the changeset rebaser object and all associated resources. There 10883 ** should be one call to this function for each successful invocation 10884 ** of sqlite3rebaser_create(). 10885 */ 10886 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 10887 10888 /* 10889 ** CAPI3REF: Streaming Versions of API functions. 10890 ** 10891 ** The six streaming API xxx_strm() functions serve similar purposes to the 10892 ** corresponding non-streaming API functions: 10893 ** 10894 ** <table border=1 style="margin-left:8ex;margin-right:8ex"> 10895 ** <tr><th>Streaming function<th>Non-streaming equivalent</th> 10896 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 10897 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 10898 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 10899 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 10900 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 10901 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 10902 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 10903 ** </table> 10904 ** 10905 ** Non-streaming functions that accept changesets (or patchsets) as input 10906 ** require that the entire changeset be stored in a single buffer in memory. 10907 ** Similarly, those that return a changeset or patchset do so by returning 10908 ** a pointer to a single large buffer allocated using sqlite3_malloc(). 10909 ** Normally this is convenient. However, if an application running in a 10910 ** low-memory environment is required to handle very large changesets, the 10911 ** large contiguous memory allocations required can become onerous. 10912 ** 10913 ** In order to avoid this problem, instead of a single large buffer, input 10914 ** is passed to a streaming API functions by way of a callback function that 10915 ** the sessions module invokes to incrementally request input data as it is 10916 ** required. In all cases, a pair of API function parameters such as 10917 ** 10918 ** <pre> 10919 ** int nChangeset, 10920 ** void *pChangeset, 10921 ** </pre> 10922 ** 10923 ** Is replaced by: 10924 ** 10925 ** <pre> 10926 ** int (*xInput)(void *pIn, void *pData, int *pnData), 10927 ** void *pIn, 10928 ** </pre> 10929 ** 10930 ** Each time the xInput callback is invoked by the sessions module, the first 10931 ** argument passed is a copy of the supplied pIn context pointer. The second 10932 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 10933 ** error occurs the xInput method should copy up to (*pnData) bytes of data 10934 ** into the buffer and set (*pnData) to the actual number of bytes copied 10935 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 10936 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite 10937 ** error code should be returned. In all cases, if an xInput callback returns 10938 ** an error, all processing is abandoned and the streaming API function 10939 ** returns a copy of the error code to the caller. 10940 ** 10941 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be 10942 ** invoked by the sessions module at any point during the lifetime of the 10943 ** iterator. If such an xInput callback returns an error, the iterator enters 10944 ** an error state, whereby all subsequent calls to iterator functions 10945 ** immediately fail with the same error code as returned by xInput. 10946 ** 10947 ** Similarly, streaming API functions that return changesets (or patchsets) 10948 ** return them in chunks by way of a callback function instead of via a 10949 ** pointer to a single large buffer. In this case, a pair of parameters such 10950 ** as: 10951 ** 10952 ** <pre> 10953 ** int *pnChangeset, 10954 ** void **ppChangeset, 10955 ** </pre> 10956 ** 10957 ** Is replaced by: 10958 ** 10959 ** <pre> 10960 ** int (*xOutput)(void *pOut, const void *pData, int nData), 10961 ** void *pOut 10962 ** </pre> 10963 ** 10964 ** The xOutput callback is invoked zero or more times to return data to 10965 ** the application. The first parameter passed to each call is a copy of the 10966 ** pOut pointer supplied by the application. The second parameter, pData, 10967 ** points to a buffer nData bytes in size containing the chunk of output 10968 ** data being returned. If the xOutput callback successfully processes the 10969 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 10970 ** it should return some other SQLite error code. In this case processing 10971 ** is immediately abandoned and the streaming API function returns a copy 10972 ** of the xOutput error code to the application. 10973 ** 10974 ** The sessions module never invokes an xOutput callback with the third 10975 ** parameter set to a value less than or equal to zero. Other than this, 10976 ** no guarantees are made as to the size of the chunks of data returned. 10977 */ 10978 SQLITE_API int sqlite3changeset_apply_strm( 10979 sqlite3 *db, /* Apply change to "main" db of this handle */ 10980 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10981 void *pIn, /* First arg for xInput */ 10982 int(*xFilter)( 10983 void *pCtx, /* Copy of sixth arg to _apply() */ 10984 const char *zTab /* Table name */ 10985 ), 10986 int(*xConflict)( 10987 void *pCtx, /* Copy of sixth arg to _apply() */ 10988 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 10989 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 10990 ), 10991 void *pCtx /* First argument passed to xConflict */ 10992 ); 10993 SQLITE_API int sqlite3changeset_apply_v2_strm( 10994 sqlite3 *db, /* Apply change to "main" db of this handle */ 10995 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 10996 void *pIn, /* First arg for xInput */ 10997 int(*xFilter)( 10998 void *pCtx, /* Copy of sixth arg to _apply() */ 10999 const char *zTab /* Table name */ 11000 ), 11001 int(*xConflict)( 11002 void *pCtx, /* Copy of sixth arg to _apply() */ 11003 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11004 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11005 ), 11006 void *pCtx, /* First argument passed to xConflict */ 11007 void **ppRebase, int *pnRebase, 11008 int flags 11009 ); 11010 SQLITE_API int sqlite3changeset_concat_strm( 11011 int (*xInputA)(void *pIn, void *pData, int *pnData), 11012 void *pInA, 11013 int (*xInputB)(void *pIn, void *pData, int *pnData), 11014 void *pInB, 11015 int (*xOutput)(void *pOut, const void *pData, int nData), 11016 void *pOut 11017 ); 11018 SQLITE_API int sqlite3changeset_invert_strm( 11019 int (*xInput)(void *pIn, void *pData, int *pnData), 11020 void *pIn, 11021 int (*xOutput)(void *pOut, const void *pData, int nData), 11022 void *pOut 11023 ); 11024 SQLITE_API int sqlite3changeset_start_strm( 11025 sqlite3_changeset_iter **pp, 11026 int (*xInput)(void *pIn, void *pData, int *pnData), 11027 void *pIn 11028 ); 11029 SQLITE_API int sqlite3changeset_start_v2_strm( 11030 sqlite3_changeset_iter **pp, 11031 int (*xInput)(void *pIn, void *pData, int *pnData), 11032 void *pIn, 11033 int flags 11034 ); 11035 SQLITE_API int sqlite3session_changeset_strm( 11036 sqlite3_session *pSession, 11037 int (*xOutput)(void *pOut, const void *pData, int nData), 11038 void *pOut 11039 ); 11040 SQLITE_API int sqlite3session_patchset_strm( 11041 sqlite3_session *pSession, 11042 int (*xOutput)(void *pOut, const void *pData, int nData), 11043 void *pOut 11044 ); 11045 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 11046 int (*xInput)(void *pIn, void *pData, int *pnData), 11047 void *pIn 11048 ); 11049 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 11050 int (*xOutput)(void *pOut, const void *pData, int nData), 11051 void *pOut 11052 ); 11053 SQLITE_API int sqlite3rebaser_rebase_strm( 11054 sqlite3_rebaser *pRebaser, 11055 int (*xInput)(void *pIn, void *pData, int *pnData), 11056 void *pIn, 11057 int (*xOutput)(void *pOut, const void *pData, int nData), 11058 void *pOut 11059 ); 11060 11061 /* 11062 ** CAPI3REF: Configure global parameters 11063 ** 11064 ** The sqlite3session_config() interface is used to make global configuration 11065 ** changes to the sessions module in order to tune it to the specific needs 11066 ** of the application. 11067 ** 11068 ** The sqlite3session_config() interface is not threadsafe. If it is invoked 11069 ** while any other thread is inside any other sessions method then the 11070 ** results are undefined. Furthermore, if it is invoked after any sessions 11071 ** related objects have been created, the results are also undefined. 11072 ** 11073 ** The first argument to the sqlite3session_config() function must be one 11074 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 11075 ** interpretation of the (void*) value passed as the second parameter and 11076 ** the effect of calling this function depends on the value of the first 11077 ** parameter. 11078 ** 11079 ** <dl> 11080 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 11081 ** By default, the sessions module streaming interfaces attempt to input 11082 ** and output data in approximately 1 KiB chunks. This operand may be used 11083 ** to set and query the value of this configuration setting. The pointer 11084 ** passed as the second argument must point to a value of type (int). 11085 ** If this value is greater than 0, it is used as the new streaming data 11086 ** chunk size for both input and output. Before returning, the (int) value 11087 ** pointed to by pArg is set to the final value of the streaming interface 11088 ** chunk size. 11089 ** </dl> 11090 ** 11091 ** This function returns SQLITE_OK if successful, or an SQLite error code 11092 ** otherwise. 11093 */ 11094 SQLITE_API int sqlite3session_config(int op, void *pArg); 11095 11096 /* 11097 ** CAPI3REF: Values for sqlite3session_config(). 11098 */ 11099 #define SQLITE_SESSION_CONFIG_STRMSIZE 1 11100 11101 /* 11102 ** Make sure we can call this stuff from C++. 11103 */ 11104 #ifdef __cplusplus 11105 } 11106 #endif 11107 11108 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 11109 11110 /******** End of sqlite3session.h *********/ 11111 /******** Begin file fts5.h *********/ 11112 /* 11113 ** 2014 May 31 11114 ** 11115 ** The author disclaims copyright to this source code. In place of 11116 ** a legal notice, here is a blessing: 11117 ** 11118 ** May you do good and not evil. 11119 ** May you find forgiveness for yourself and forgive others. 11120 ** May you share freely, never taking more than you give. 11121 ** 11122 ****************************************************************************** 11123 ** 11124 ** Interfaces to extend FTS5. Using the interfaces defined in this file, 11125 ** FTS5 may be extended with: 11126 ** 11127 ** * custom tokenizers, and 11128 ** * custom auxiliary functions. 11129 */ 11130 11131 11132 #ifndef _FTS5_H 11133 #define _FTS5_H 11134 11135 11136 #ifdef __cplusplus 11137 extern "C" { 11138 #endif 11139 11140 /************************************************************************* 11141 ** CUSTOM AUXILIARY FUNCTIONS 11142 ** 11143 ** Virtual table implementations may overload SQL functions by implementing 11144 ** the sqlite3_module.xFindFunction() method. 11145 */ 11146 11147 typedef struct Fts5ExtensionApi Fts5ExtensionApi; 11148 typedef struct Fts5Context Fts5Context; 11149 typedef struct Fts5PhraseIter Fts5PhraseIter; 11150 11151 typedef void (*fts5_extension_function)( 11152 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 11153 Fts5Context *pFts, /* First arg to pass to pApi functions */ 11154 sqlite3_context *pCtx, /* Context for returning result/error */ 11155 int nVal, /* Number of values in apVal[] array */ 11156 sqlite3_value **apVal /* Array of trailing arguments */ 11157 ); 11158 11159 struct Fts5PhraseIter { 11160 const unsigned char *a; 11161 const unsigned char *b; 11162 }; 11163 11164 /* 11165 ** EXTENSION API FUNCTIONS 11166 ** 11167 ** xUserData(pFts): 11168 ** Return a copy of the context pointer the extension function was 11169 ** registered with. 11170 ** 11171 ** xColumnTotalSize(pFts, iCol, pnToken): 11172 ** If parameter iCol is less than zero, set output variable *pnToken 11173 ** to the total number of tokens in the FTS5 table. Or, if iCol is 11174 ** non-negative but less than the number of columns in the table, return 11175 ** the total number of tokens in column iCol, considering all rows in 11176 ** the FTS5 table. 11177 ** 11178 ** If parameter iCol is greater than or equal to the number of columns 11179 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11180 ** an OOM condition or IO error), an appropriate SQLite error code is 11181 ** returned. 11182 ** 11183 ** xColumnCount(pFts): 11184 ** Return the number of columns in the table. 11185 ** 11186 ** xColumnSize(pFts, iCol, pnToken): 11187 ** If parameter iCol is less than zero, set output variable *pnToken 11188 ** to the total number of tokens in the current row. Or, if iCol is 11189 ** non-negative but less than the number of columns in the table, set 11190 ** *pnToken to the number of tokens in column iCol of the current row. 11191 ** 11192 ** If parameter iCol is greater than or equal to the number of columns 11193 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 11194 ** an OOM condition or IO error), an appropriate SQLite error code is 11195 ** returned. 11196 ** 11197 ** This function may be quite inefficient if used with an FTS5 table 11198 ** created with the "columnsize=0" option. 11199 ** 11200 ** xColumnText: 11201 ** This function attempts to retrieve the text of column iCol of the 11202 ** current document. If successful, (*pz) is set to point to a buffer 11203 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 11204 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 11205 ** if an error occurs, an SQLite error code is returned and the final values 11206 ** of (*pz) and (*pn) are undefined. 11207 ** 11208 ** xPhraseCount: 11209 ** Returns the number of phrases in the current query expression. 11210 ** 11211 ** xPhraseSize: 11212 ** Returns the number of tokens in phrase iPhrase of the query. Phrases 11213 ** are numbered starting from zero. 11214 ** 11215 ** xInstCount: 11216 ** Set *pnInst to the total number of occurrences of all phrases within 11217 ** the query within the current row. Return SQLITE_OK if successful, or 11218 ** an error code (i.e. SQLITE_NOMEM) if an error occurs. 11219 ** 11220 ** This API can be quite slow if used with an FTS5 table created with the 11221 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11222 ** with either "detail=none" or "detail=column" and "content=" option 11223 ** (i.e. if it is a contentless table), then this API always returns 0. 11224 ** 11225 ** xInst: 11226 ** Query for the details of phrase match iIdx within the current row. 11227 ** Phrase matches are numbered starting from zero, so the iIdx argument 11228 ** should be greater than or equal to zero and smaller than the value 11229 ** output by xInstCount(). 11230 ** 11231 ** Usually, output parameter *piPhrase is set to the phrase number, *piCol 11232 ** to the column in which it occurs and *piOff the token offset of the 11233 ** first token of the phrase. The exception is if the table was created 11234 ** with the offsets=0 option specified. In this case *piOff is always 11235 ** set to -1. 11236 ** 11237 ** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM) 11238 ** if an error occurs. 11239 ** 11240 ** This API can be quite slow if used with an FTS5 table created with the 11241 ** "detail=none" or "detail=column" option. 11242 ** 11243 ** xRowid: 11244 ** Returns the rowid of the current row. 11245 ** 11246 ** xTokenize: 11247 ** Tokenize text using the tokenizer belonging to the FTS5 table. 11248 ** 11249 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 11250 ** This API function is used to query the FTS table for phrase iPhrase 11251 ** of the current query. Specifically, a query equivalent to: 11252 ** 11253 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 11254 ** 11255 ** with $p set to a phrase equivalent to the phrase iPhrase of the 11256 ** current query is executed. Any column filter that applies to 11257 ** phrase iPhrase of the current query is included in $p. For each 11258 ** row visited, the callback function passed as the fourth argument 11259 ** is invoked. The context and API objects passed to the callback 11260 ** function may be used to access the properties of each matched row. 11261 ** Invoking Api.xUserData() returns a copy of the pointer passed as 11262 ** the third argument to pUserData. 11263 ** 11264 ** If the callback function returns any value other than SQLITE_OK, the 11265 ** query is abandoned and the xQueryPhrase function returns immediately. 11266 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 11267 ** Otherwise, the error code is propagated upwards. 11268 ** 11269 ** If the query runs to completion without incident, SQLITE_OK is returned. 11270 ** Or, if some error occurs before the query completes or is aborted by 11271 ** the callback, an SQLite error code is returned. 11272 ** 11273 ** 11274 ** xSetAuxdata(pFts5, pAux, xDelete) 11275 ** 11276 ** Save the pointer passed as the second argument as the extension functions 11277 ** "auxiliary data". The pointer may then be retrieved by the current or any 11278 ** future invocation of the same fts5 extension function made as part of 11279 ** of the same MATCH query using the xGetAuxdata() API. 11280 ** 11281 ** Each extension function is allocated a single auxiliary data slot for 11282 ** each FTS query (MATCH expression). If the extension function is invoked 11283 ** more than once for a single FTS query, then all invocations share a 11284 ** single auxiliary data context. 11285 ** 11286 ** If there is already an auxiliary data pointer when this function is 11287 ** invoked, then it is replaced by the new pointer. If an xDelete callback 11288 ** was specified along with the original pointer, it is invoked at this 11289 ** point. 11290 ** 11291 ** The xDelete callback, if one is specified, is also invoked on the 11292 ** auxiliary data pointer after the FTS5 query has finished. 11293 ** 11294 ** If an error (e.g. an OOM condition) occurs within this function, an 11295 ** the auxiliary data is set to NULL and an error code returned. If the 11296 ** xDelete parameter was not NULL, it is invoked on the auxiliary data 11297 ** pointer before returning. 11298 ** 11299 ** 11300 ** xGetAuxdata(pFts5, bClear) 11301 ** 11302 ** Returns the current auxiliary data pointer for the fts5 extension 11303 ** function. See the xSetAuxdata() method for details. 11304 ** 11305 ** If the bClear argument is non-zero, then the auxiliary data is cleared 11306 ** (set to NULL) before this function returns. In this case the xDelete, 11307 ** if any, is not invoked. 11308 ** 11309 ** 11310 ** xRowCount(pFts5, pnRow) 11311 ** 11312 ** This function is used to retrieve the total number of rows in the table. 11313 ** In other words, the same value that would be returned by: 11314 ** 11315 ** SELECT count(*) FROM ftstable; 11316 ** 11317 ** xPhraseFirst() 11318 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext 11319 ** method, to iterate through all instances of a single query phrase within 11320 ** the current row. This is the same information as is accessible via the 11321 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 11322 ** to use, this API may be faster under some circumstances. To iterate 11323 ** through instances of phrase iPhrase, use the following code: 11324 ** 11325 ** Fts5PhraseIter iter; 11326 ** int iCol, iOff; 11327 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 11328 ** iCol>=0; 11329 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 11330 ** ){ 11331 ** // An instance of phrase iPhrase at offset iOff of column iCol 11332 ** } 11333 ** 11334 ** The Fts5PhraseIter structure is defined above. Applications should not 11335 ** modify this structure directly - it should only be used as shown above 11336 ** with the xPhraseFirst() and xPhraseNext() API methods (and by 11337 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 11338 ** 11339 ** This API can be quite slow if used with an FTS5 table created with the 11340 ** "detail=none" or "detail=column" option. If the FTS5 table is created 11341 ** with either "detail=none" or "detail=column" and "content=" option 11342 ** (i.e. if it is a contentless table), then this API always iterates 11343 ** through an empty set (all calls to xPhraseFirst() set iCol to -1). 11344 ** 11345 ** xPhraseNext() 11346 ** See xPhraseFirst above. 11347 ** 11348 ** xPhraseFirstColumn() 11349 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 11350 ** and xPhraseNext() APIs described above. The difference is that instead 11351 ** of iterating through all instances of a phrase in the current row, these 11352 ** APIs are used to iterate through the set of columns in the current row 11353 ** that contain one or more instances of a specified phrase. For example: 11354 ** 11355 ** Fts5PhraseIter iter; 11356 ** int iCol; 11357 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 11358 ** iCol>=0; 11359 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 11360 ** ){ 11361 ** // Column iCol contains at least one instance of phrase iPhrase 11362 ** } 11363 ** 11364 ** This API can be quite slow if used with an FTS5 table created with the 11365 ** "detail=none" option. If the FTS5 table is created with either 11366 ** "detail=none" "content=" option (i.e. if it is a contentless table), 11367 ** then this API always iterates through an empty set (all calls to 11368 ** xPhraseFirstColumn() set iCol to -1). 11369 ** 11370 ** The information accessed using this API and its companion 11371 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 11372 ** (or xInst/xInstCount). The chief advantage of this API is that it is 11373 ** significantly more efficient than those alternatives when used with 11374 ** "detail=column" tables. 11375 ** 11376 ** xPhraseNextColumn() 11377 ** See xPhraseFirstColumn above. 11378 */ 11379 struct Fts5ExtensionApi { 11380 int iVersion; /* Currently always set to 3 */ 11381 11382 void *(*xUserData)(Fts5Context*); 11383 11384 int (*xColumnCount)(Fts5Context*); 11385 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 11386 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 11387 11388 int (*xTokenize)(Fts5Context*, 11389 const char *pText, int nText, /* Text to tokenize */ 11390 void *pCtx, /* Context passed to xToken() */ 11391 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 11392 ); 11393 11394 int (*xPhraseCount)(Fts5Context*); 11395 int (*xPhraseSize)(Fts5Context*, int iPhrase); 11396 11397 int (*xInstCount)(Fts5Context*, int *pnInst); 11398 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 11399 11400 sqlite3_int64 (*xRowid)(Fts5Context*); 11401 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 11402 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 11403 11404 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 11405 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 11406 ); 11407 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 11408 void *(*xGetAuxdata)(Fts5Context*, int bClear); 11409 11410 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 11411 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 11412 11413 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 11414 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 11415 }; 11416 11417 /* 11418 ** CUSTOM AUXILIARY FUNCTIONS 11419 *************************************************************************/ 11420 11421 /************************************************************************* 11422 ** CUSTOM TOKENIZERS 11423 ** 11424 ** Applications may also register custom tokenizer types. A tokenizer 11425 ** is registered by providing fts5 with a populated instance of the 11426 ** following structure. All structure methods must be defined, setting 11427 ** any member of the fts5_tokenizer struct to NULL leads to undefined 11428 ** behaviour. The structure methods are expected to function as follows: 11429 ** 11430 ** xCreate: 11431 ** This function is used to allocate and initialize a tokenizer instance. 11432 ** A tokenizer instance is required to actually tokenize text. 11433 ** 11434 ** The first argument passed to this function is a copy of the (void*) 11435 ** pointer provided by the application when the fts5_tokenizer object 11436 ** was registered with FTS5 (the third argument to xCreateTokenizer()). 11437 ** The second and third arguments are an array of nul-terminated strings 11438 ** containing the tokenizer arguments, if any, specified following the 11439 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 11440 ** to create the FTS5 table. 11441 ** 11442 ** The final argument is an output variable. If successful, (*ppOut) 11443 ** should be set to point to the new tokenizer handle and SQLITE_OK 11444 ** returned. If an error occurs, some value other than SQLITE_OK should 11445 ** be returned. In this case, fts5 assumes that the final value of *ppOut 11446 ** is undefined. 11447 ** 11448 ** xDelete: 11449 ** This function is invoked to delete a tokenizer handle previously 11450 ** allocated using xCreate(). Fts5 guarantees that this function will 11451 ** be invoked exactly once for each successful call to xCreate(). 11452 ** 11453 ** xTokenize: 11454 ** This function is expected to tokenize the nText byte string indicated 11455 ** by argument pText. pText may or may not be nul-terminated. The first 11456 ** argument passed to this function is a pointer to an Fts5Tokenizer object 11457 ** returned by an earlier call to xCreate(). 11458 ** 11459 ** The second argument indicates the reason that FTS5 is requesting 11460 ** tokenization of the supplied text. This is always one of the following 11461 ** four values: 11462 ** 11463 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 11464 ** or removed from the FTS table. The tokenizer is being invoked to 11465 ** determine the set of tokens to add to (or delete from) the 11466 ** FTS index. 11467 ** 11468 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 11469 ** against the FTS index. The tokenizer is being called to tokenize 11470 ** a bareword or quoted string specified as part of the query. 11471 ** 11472 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 11473 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 11474 ** followed by a "*" character, indicating that the last token 11475 ** returned by the tokenizer will be treated as a token prefix. 11476 ** 11477 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 11478 ** satisfy an fts5_api.xTokenize() request made by an auxiliary 11479 ** function. Or an fts5_api.xColumnSize() request made by the same 11480 ** on a columnsize=0 database. 11481 ** </ul> 11482 ** 11483 ** For each token in the input string, the supplied callback xToken() must 11484 ** be invoked. The first argument to it should be a copy of the pointer 11485 ** passed as the second argument to xTokenize(). The third and fourth 11486 ** arguments are a pointer to a buffer containing the token text, and the 11487 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets 11488 ** of the first byte of and first byte immediately following the text from 11489 ** which the token is derived within the input. 11490 ** 11491 ** The second argument passed to the xToken() callback ("tflags") should 11492 ** normally be set to 0. The exception is if the tokenizer supports 11493 ** synonyms. In this case see the discussion below for details. 11494 ** 11495 ** FTS5 assumes the xToken() callback is invoked for each token in the 11496 ** order that they occur within the input text. 11497 ** 11498 ** If an xToken() callback returns any value other than SQLITE_OK, then 11499 ** the tokenization should be abandoned and the xTokenize() method should 11500 ** immediately return a copy of the xToken() return value. Or, if the 11501 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 11502 ** if an error occurs with the xTokenize() implementation itself, it 11503 ** may abandon the tokenization and return any error code other than 11504 ** SQLITE_OK or SQLITE_DONE. 11505 ** 11506 ** SYNONYM SUPPORT 11507 ** 11508 ** Custom tokenizers may also support synonyms. Consider a case in which a 11509 ** user wishes to query for a phrase such as "first place". Using the 11510 ** built-in tokenizers, the FTS5 query 'first + place' will match instances 11511 ** of "first place" within the document set, but not alternative forms 11512 ** such as "1st place". In some applications, it would be better to match 11513 ** all instances of "first place" or "1st place" regardless of which form 11514 ** the user specified in the MATCH query text. 11515 ** 11516 ** There are several ways to approach this in FTS5: 11517 ** 11518 ** <ol><li> By mapping all synonyms to a single token. In this case, the 11519 ** In the above example, this means that the tokenizer returns the 11520 ** same token for inputs "first" and "1st". Say that token is in 11521 ** fact "first", so that when the user inserts the document "I won 11522 ** 1st place" entries are added to the index for tokens "i", "won", 11523 ** "first" and "place". If the user then queries for '1st + place', 11524 ** the tokenizer substitutes "first" for "1st" and the query works 11525 ** as expected. 11526 ** 11527 ** <li> By adding multiple synonyms for a single term to the FTS index. 11528 ** In this case, when tokenizing query text, the tokenizer may 11529 ** provide multiple synonyms for a single term within the document. 11530 ** FTS5 then queries the index for each synonym individually. For 11531 ** example, faced with the query: 11532 ** 11533 ** <codeblock> 11534 ** ... MATCH 'first place'</codeblock> 11535 ** 11536 ** the tokenizer offers both "1st" and "first" as synonyms for the 11537 ** first token in the MATCH query and FTS5 effectively runs a query 11538 ** similar to: 11539 ** 11540 ** <codeblock> 11541 ** ... MATCH '(first OR 1st) place'</codeblock> 11542 ** 11543 ** except that, for the purposes of auxiliary functions, the query 11544 ** still appears to contain just two phrases - "(first OR 1st)" 11545 ** being treated as a single phrase. 11546 ** 11547 ** <li> By adding multiple synonyms for a single term to the FTS index. 11548 ** Using this method, when tokenizing document text, the tokenizer 11549 ** provides multiple synonyms for each token. So that when a 11550 ** document such as "I won first place" is tokenized, entries are 11551 ** added to the FTS index for "i", "won", "first", "1st" and 11552 ** "place". 11553 ** 11554 ** This way, even if the tokenizer does not provide synonyms 11555 ** when tokenizing query text (it should not - to do would be 11556 ** inefficient), it doesn't matter if the user queries for 11557 ** 'first + place' or '1st + place', as there are entries in the 11558 ** FTS index corresponding to both forms of the first token. 11559 ** </ol> 11560 ** 11561 ** Whether it is parsing document or query text, any call to xToken that 11562 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 11563 ** is considered to supply a synonym for the previous token. For example, 11564 ** when parsing the document "I won first place", a tokenizer that supports 11565 ** synonyms would call xToken() 5 times, as follows: 11566 ** 11567 ** <codeblock> 11568 ** xToken(pCtx, 0, "i", 1, 0, 1); 11569 ** xToken(pCtx, 0, "won", 3, 2, 5); 11570 ** xToken(pCtx, 0, "first", 5, 6, 11); 11571 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 11572 ** xToken(pCtx, 0, "place", 5, 12, 17); 11573 **</codeblock> 11574 ** 11575 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 11576 ** xToken() is called. Multiple synonyms may be specified for a single token 11577 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 11578 ** There is no limit to the number of synonyms that may be provided for a 11579 ** single token. 11580 ** 11581 ** In many cases, method (1) above is the best approach. It does not add 11582 ** extra data to the FTS index or require FTS5 to query for multiple terms, 11583 ** so it is efficient in terms of disk space and query speed. However, it 11584 ** does not support prefix queries very well. If, as suggested above, the 11585 ** token "first" is substituted for "1st" by the tokenizer, then the query: 11586 ** 11587 ** <codeblock> 11588 ** ... MATCH '1s*'</codeblock> 11589 ** 11590 ** will not match documents that contain the token "1st" (as the tokenizer 11591 ** will probably not map "1s" to any prefix of "first"). 11592 ** 11593 ** For full prefix support, method (3) may be preferred. In this case, 11594 ** because the index contains entries for both "first" and "1st", prefix 11595 ** queries such as 'fi*' or '1s*' will match correctly. However, because 11596 ** extra entries are added to the FTS index, this method uses more space 11597 ** within the database. 11598 ** 11599 ** Method (2) offers a midpoint between (1) and (3). Using this method, 11600 ** a query such as '1s*' will match documents that contain the literal 11601 ** token "1st", but not "first" (assuming the tokenizer is not able to 11602 ** provide synonyms for prefixes). However, a non-prefix query like '1st' 11603 ** will match against "1st" and "first". This method does not require 11604 ** extra disk space, as no extra entries are added to the FTS index. 11605 ** On the other hand, it may require more CPU cycles to run MATCH queries, 11606 ** as separate queries of the FTS index are required for each synonym. 11607 ** 11608 ** When using methods (2) or (3), it is important that the tokenizer only 11609 ** provide synonyms when tokenizing document text (method (2)) or query 11610 ** text (method (3)), not both. Doing so will not cause any errors, but is 11611 ** inefficient. 11612 */ 11613 typedef struct Fts5Tokenizer Fts5Tokenizer; 11614 typedef struct fts5_tokenizer fts5_tokenizer; 11615 struct fts5_tokenizer { 11616 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 11617 void (*xDelete)(Fts5Tokenizer*); 11618 int (*xTokenize)(Fts5Tokenizer*, 11619 void *pCtx, 11620 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 11621 const char *pText, int nText, 11622 int (*xToken)( 11623 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 11624 int tflags, /* Mask of FTS5_TOKEN_* flags */ 11625 const char *pToken, /* Pointer to buffer containing token */ 11626 int nToken, /* Size of token in bytes */ 11627 int iStart, /* Byte offset of token within input text */ 11628 int iEnd /* Byte offset of end of token within input text */ 11629 ) 11630 ); 11631 }; 11632 11633 /* Flags that may be passed as the third argument to xTokenize() */ 11634 #define FTS5_TOKENIZE_QUERY 0x0001 11635 #define FTS5_TOKENIZE_PREFIX 0x0002 11636 #define FTS5_TOKENIZE_DOCUMENT 0x0004 11637 #define FTS5_TOKENIZE_AUX 0x0008 11638 11639 /* Flags that may be passed by the tokenizer implementation back to FTS5 11640 ** as the third argument to the supplied xToken callback. */ 11641 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 11642 11643 /* 11644 ** END OF CUSTOM TOKENIZERS 11645 *************************************************************************/ 11646 11647 /************************************************************************* 11648 ** FTS5 EXTENSION REGISTRATION API 11649 */ 11650 typedef struct fts5_api fts5_api; 11651 struct fts5_api { 11652 int iVersion; /* Currently always set to 2 */ 11653 11654 /* Create a new tokenizer */ 11655 int (*xCreateTokenizer)( 11656 fts5_api *pApi, 11657 const char *zName, 11658 void *pContext, 11659 fts5_tokenizer *pTokenizer, 11660 void (*xDestroy)(void*) 11661 ); 11662 11663 /* Find an existing tokenizer */ 11664 int (*xFindTokenizer)( 11665 fts5_api *pApi, 11666 const char *zName, 11667 void **ppContext, 11668 fts5_tokenizer *pTokenizer 11669 ); 11670 11671 /* Create a new auxiliary function */ 11672 int (*xCreateFunction)( 11673 fts5_api *pApi, 11674 const char *zName, 11675 void *pContext, 11676 fts5_extension_function xFunction, 11677 void (*xDestroy)(void*) 11678 ); 11679 }; 11680 11681 /* 11682 ** END OF REGISTRATION API 11683 *************************************************************************/ 11684 11685 #ifdef __cplusplus 11686 } /* end of the 'extern "C"' block */ 11687 #endif 11688 11689 #endif /* _FTS5_H */ 11690 11691 /******** End of fts5.h *********/ 11692