1/* 2** 2001 September 15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve to make minor changes if 22** experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are suppose to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32** 33** @(#) $Id: sqlite.h.in,v 1.278 2007/12/13 21:54:11 drh Exp $ 34*/ 35#ifndef _SQLITE3_H_ 36#define _SQLITE3_H_ 37#include <stdarg.h> /* Needed for the definition of va_list */ 38 39/* 40** Make sure we can call this stuff from C++. 41*/ 42#ifdef __cplusplus 43extern "C" { 44#endif 45 46 47/* 48** Add the ability to override 'extern' 49*/ 50#ifndef SQLITE_EXTERN 51# define SQLITE_EXTERN extern 52#endif 53 54/* 55** Make sure these symbols where not defined by some previous header 56** file. 57*/ 58#ifdef SQLITE_VERSION 59# undef SQLITE_VERSION 60#endif 61#ifdef SQLITE_VERSION_NUMBER 62# undef SQLITE_VERSION_NUMBER 63#endif 64 65/* 66** CAPI3REF: Compile-Time Library Version Numbers {F10010} 67** 68** {F10011} The #define in the sqlite3.h header file named 69** SQLITE_VERSION resolves to a string literal that identifies 70** the version of the SQLite library in the format "X.Y.Z", where 71** X is the major version number, Y is the minor version number and Z 72** is the release number. The X.Y.Z might be followed by "alpha" or "beta". 73** {END} For example "3.1.1beta". 74** 75** The X value is always 3 in SQLite. The X value only changes when 76** backwards compatibility is broken and we intend to never break 77** backwards compatibility. The Y value only changes when 78** there are major feature enhancements that are forwards compatible 79** but not backwards compatible. The Z value is incremented with 80** each release but resets back to 0 when Y is incremented. 81** 82** {F10014} The SQLITE_VERSION_NUMBER #define resolves to an integer 83** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are as 84** with SQLITE_VERSION. {END} For example, for version "3.1.1beta", 85** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using 86** version 3.1.1 or greater at compile time, programs may use the test 87** (SQLITE_VERSION_NUMBER>=3001001). 88** 89** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. 90*/ 91#define SQLITE_VERSION "--VERS--" 92#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 93 94/* 95** CAPI3REF: Run-Time Library Version Numbers {F10020} 96** 97** {F10021} The sqlite3_libversion_number() interface returns an integer 98** equal to [SQLITE_VERSION_NUMBER]. {END} The value returned 99** by this routine should only be different from the header values 100** if the application is compiled using an sqlite3.h header from a 101** different version of SQLite than library. Cautious programmers might 102** include a check in their application to verify that 103** sqlite3_libversion_number() always returns the value 104** [SQLITE_VERSION_NUMBER]. 105** 106** {F10022} The sqlite3_version[] string constant contains the text of the 107** [SQLITE_VERSION] string. {F10023} The sqlite3_libversion() function returns 108** a pointer to the sqlite3_version[] string constant. {END} The 109** sqlite3_libversion() function 110** is provided for DLL users who can only access functions and not 111** constants within the DLL. 112*/ 113SQLITE_EXTERN const char sqlite3_version[]; 114const char *sqlite3_libversion(void); 115int sqlite3_libversion_number(void); 116 117/* 118** CAPI3REF: Test To See If The Library Is Threadsafe {F10100} 119** 120** {F10101} The sqlite3_threadsafe() routine returns nonzero 121** if SQLite was compiled with its mutexes enabled or zero if 122** SQLite was compiled with mutexes disabled. {END} If this 123** routine returns false, then it is not safe for simultaneously 124** running threads to both invoke SQLite interfaces. 125** 126** Really all this routine does is return true if SQLite was 127** compiled with the -DSQLITE_THREADSAFE=1 option and false if 128** compiled with -DSQLITE_THREADSAFE=0. If SQLite uses an 129** application-defined mutex subsystem, malloc subsystem, collating 130** sequence, VFS, SQL function, progress callback, commit hook, 131** extension, or other accessories and these add-ons are not 132** threadsafe, then clearly the combination will not be threadsafe 133** either. Hence, this routine never reports that the library 134** is guaranteed to be threadsafe, only when it is guaranteed not 135** to be. 136*/ 137int sqlite3_threadsafe(void); 138 139/* 140** CAPI3REF: Database Connection Handle {F12000} 141** 142** Each open SQLite database is represented by pointer to an instance of the 143** opaque structure named "sqlite3". It is useful to think of an sqlite3 144** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 145** [sqlite3_open_v2()] interfaces are its constructors 146** and [sqlite3_close()] is its destructor. There are many other interfaces 147** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and 148** [sqlite3_busy_timeout()] to name but three) that are methods on this 149** object. 150*/ 151typedef struct sqlite3 sqlite3; 152 153 154/* 155** CAPI3REF: 64-Bit Integer Types {F10200} 156** 157** Because there is no cross-platform way to specify such types 158** SQLite includes typedefs for 64-bit signed and unsigned integers. 159** {F10201} The sqlite_int64 and sqlite3_int64 types specify a 160** 64-bit signed integer. {F10202} The sqlite_uint64 and 161** sqlite3_uint64 types specify a 64-bit unsigned integer. {END} 162** 163** The sqlite3_int64 and sqlite3_uint64 are the preferred type 164** definitions. The sqlite_int64 and sqlite_uint64 types are 165** supported for backwards compatibility only. 166*/ 167#ifdef SQLITE_INT64_TYPE 168 typedef SQLITE_INT64_TYPE sqlite_int64; 169 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 170#elif defined(_MSC_VER) || defined(__BORLANDC__) 171 typedef __int64 sqlite_int64; 172 typedef unsigned __int64 sqlite_uint64; 173#else 174 typedef long long int sqlite_int64; 175 typedef unsigned long long int sqlite_uint64; 176#endif 177typedef sqlite_int64 sqlite3_int64; 178typedef sqlite_uint64 sqlite3_uint64; 179 180/* 181** If compiling for a processor that lacks floating point support, 182** substitute integer for floating-point 183*/ 184#ifdef SQLITE_OMIT_FLOATING_POINT 185# define double sqlite3_int64 186#endif 187 188/* 189** CAPI3REF: Closing A Database Connection {F12010} 190** 191** {F12011} The sqlite3_close() interfaces destroys an [sqlite3] object 192** allocated by a prior call to [sqlite3_open()], [sqlite3_open16()], or 193** [sqlite3_open_v2()]. {F12012} Sqlite3_close() releases all 194** memory used by the connection and closes all open files. {END}. 195** 196** {F12013} If the database connection contains 197** [sqlite3_stmt | prepared statements] that have not been finalized 198** by [sqlite3_finalize()], then sqlite3_close() returns SQLITE_BUSY 199** and leaves the connection open. {F12014} Giving sqlite3_close() 200** a NULL pointer is a harmless no-op. {END} 201** 202** {U12015} Passing this routine a database connection that has already been 203** closed results in undefined behavior. {U12016} If other interfaces that 204** reference the same database connection are pending (either in the 205** same thread or in different threads) when this routine is called, 206** then the behavior is undefined and is almost certainly undesirable. 207*/ 208int sqlite3_close(sqlite3 *); 209 210/* 211** The type for a callback function. 212** This is legacy and deprecated. It is included for historical 213** compatibility and is not documented. 214*/ 215typedef int (*sqlite3_callback)(void*,int,char**, char**); 216 217/* 218** CAPI3REF: One-Step Query Execution Interface {F12100} 219** 220** {F12101} The sqlite3_exec() interface evaluates zero or more 221** UTF-8 encoded, semicolon-separated SQL statements in the zero-terminated 222** string of its second argument. {F12102} The SQL 223** statements are evaluated in the context of the database connection 224** specified by in the first argument. 225** {F12103} SQL statements are prepared one by one using 226** [sqlite3_prepare()] or the equivalent, evaluated 227** using one or more calls to [sqlite3_step()], then destroyed 228** using [sqlite3_finalize()]. {F12104} The return value of 229** sqlite3_exec() is SQLITE_OK if all SQL statement run 230** successfully. 231** 232** {F12105} If one or more of the SQL statements handed to 233** sqlite3_exec() are queries, then 234** the callback function specified by the 3rd parameter is 235** invoked once for each row of the query result. {F12106} 236** If the callback returns a non-zero value then the query 237** is aborted, all subsequent SQL statements 238** are skipped and the sqlite3_exec() function returns the [SQLITE_ABORT]. 239** 240** {F12107} The 4th parameter to sqlite3_exec() is an arbitrary pointer 241** that is passed through to the callback function as its first parameter. 242** 243** {F12108} The 2nd parameter to the callback function is the number of 244** columns in the query result. {F12109} The 3rd parameter to the callback 245** is an array of pointers to strings holding the values for each column 246** as extracted using [sqlite3_column_text()]. NULL values in the result 247** set result in a NULL pointer. All other value are in their UTF-8 248** string representation. {F12117} 249** The 4th parameter to the callback is an array of strings 250** obtained using [sqlite3_column_name()] and holding 251** the names of each column, also in UTF-8. 252** 253** {F12110} The callback function may be NULL, even for queries. A NULL 254** callback is not an error. It just means that no callback 255** will be invoked. 256** 257** {F12112} If an error occurs while parsing or evaluating the SQL 258** then an appropriate error message is written into memory obtained 259** from [sqlite3_malloc()] and *errmsg is made to point to that message 260** assuming errmsg is not NULL. 261** {U12113} The calling function is responsible for freeing the memory 262** using [sqlite3_free()]. 263** {F12116} If [sqlite3_malloc()] fails while attempting to generate 264** the error message, *errmsg is set to NULL. 265** {F12114} If errmsg is NULL then no attempt is made to generate an 266** error message. <todo>Is the return code SQLITE_NOMEM or the original 267** error code?</todo> <todo>What happens if there are multiple errors? 268** Do we get code for the first error, or is the choice of reported 269** error arbitrary?</todo> 270** 271** {F12115} The return value is is SQLITE_OK if there are no errors and 272** some other [SQLITE_OK | return code] if there is an error. 273** The particular return value depends on the type of error. {END} 274*/ 275int sqlite3_exec( 276 sqlite3*, /* An open database */ 277 const char *sql, /* SQL to be evaluted */ 278 int (*callback)(void*,int,char**,char**), /* Callback function */ 279 void *, /* 1st argument to callback */ 280 char **errmsg /* Error msg written here */ 281); 282 283/* 284** CAPI3REF: Result Codes {F10210} 285** KEYWORDS: SQLITE_OK 286** 287** Many SQLite functions return an integer result code from the set shown 288** above in order to indicates success or failure. 289** 290** {F10211} The result codes shown here are the only ones returned 291** by SQLite in its default configuration. {F10212} However, the 292** [sqlite3_extended_result_codes()] API can be used to set a database 293** connectoin to return more detailed result codes. {END} 294** 295** See also: [SQLITE_IOERR_READ | extended result codes] 296** 297*/ 298#define SQLITE_OK 0 /* Successful result */ 299/* beginning-of-error-codes */ 300#define SQLITE_ERROR 1 /* SQL error or missing database */ 301#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 302#define SQLITE_PERM 3 /* Access permission denied */ 303#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 304#define SQLITE_BUSY 5 /* The database file is locked */ 305#define SQLITE_LOCKED 6 /* A table in the database is locked */ 306#define SQLITE_NOMEM 7 /* A malloc() failed */ 307#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 308#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 309#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 310#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 311#define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ 312#define SQLITE_FULL 13 /* Insertion failed because database is full */ 313#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 314#define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ 315#define SQLITE_EMPTY 16 /* Database is empty */ 316#define SQLITE_SCHEMA 17 /* The database schema changed */ 317#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 318#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 319#define SQLITE_MISMATCH 20 /* Data type mismatch */ 320#define SQLITE_MISUSE 21 /* Library used incorrectly */ 321#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 322#define SQLITE_AUTH 23 /* Authorization denied */ 323#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 324#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 325#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 326#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 327#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 328/* end-of-error-codes */ 329 330/* 331** CAPI3REF: Extended Result Codes {F10220} 332** 333** In its default configuration, SQLite API routines return one of 26 integer 334** [SQLITE_OK | result codes]. However, experience has shown that 335** many of these result codes are too course-grained. They do not provide as 336** much information about problems as programmers might like. In an effort to 337** address this, newer versions of SQLite (version 3.3.8 and later) include 338** support for additional result codes that provide more detailed information 339** about errors. {F10221} The extended result codes are enabled or disabled 340** for each database connection using the [sqlite3_extended_result_codes()] 341** API. {END} 342** 343** Some of the available extended result codes are listed above. 344** We expect the number of extended result codes will be expand 345** over time. {U10422} Software that uses extended result codes should expect 346** to see new result codes in future releases of SQLite. {END} 347** 348** {F10223} The symbolic name for an extended result code always contains 349** a related primary result code as a prefix. {F10224} Primary result 350** codes contain a single "_" character. {F10225} Extended result codes 351** contain two or more "_" characters. {F10226} The numeric value of an 352** extended result code can be converted to its 353** corresponding primary result code by masking off the lower 8 bytes. {END} 354** 355** The SQLITE_OK result code will never be extended. It will always 356** be exactly zero. 357*/ 358#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 359#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 360#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 361#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 362#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 363#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 364#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 365#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 366#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 367#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 368#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 369#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 370 371/* 372** CAPI3REF: Flags For File Open Operations {F10230} 373** 374** {F10231} Some combination of the these bit values are used as the 375** third argument to the [sqlite3_open_v2()] interface and 376** as fourth argument to the xOpen method of the 377** [sqlite3_vfs] object. 378*/ 379#define SQLITE_OPEN_READONLY 0x00000001 380#define SQLITE_OPEN_READWRITE 0x00000002 381#define SQLITE_OPEN_CREATE 0x00000004 382#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 383#define SQLITE_OPEN_EXCLUSIVE 0x00000010 384#define SQLITE_OPEN_MAIN_DB 0x00000100 385#define SQLITE_OPEN_TEMP_DB 0x00000200 386#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 387#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 388#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 389#define SQLITE_OPEN_SUBJOURNAL 0x00002000 390#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 391 392/* 393** CAPI3REF: Device Characteristics {F10240} 394** 395** {F10241} The xDeviceCapabilities method of the [sqlite3_io_methods] 396** object returns an integer which is a vector of the these 397** bit values expressing I/O characteristics of the mass storage 398** device that holds the file that the [sqlite3_io_methods] 399** refers to. {END} 400** 401** {F10242} The SQLITE_IOCAP_ATOMIC property means that all writes of 402** any size are atomic. {F10243} The SQLITE_IOCAP_ATOMICnnn values 403** mean that writes of blocks that are nnn bytes in size and 404** are aligned to an address which is an integer multiple of 405** nnn are atomic. {F10244} The SQLITE_IOCAP_SAFE_APPEND value means 406** that when data is appended to a file, the data is appended 407** first then the size of the file is extended, never the other 408** way around. {F10245} The SQLITE_IOCAP_SEQUENTIAL property means that 409** information is written to disk in the same order as calls 410** to xWrite(). 411*/ 412#define SQLITE_IOCAP_ATOMIC 0x00000001 413#define SQLITE_IOCAP_ATOMIC512 0x00000002 414#define SQLITE_IOCAP_ATOMIC1K 0x00000004 415#define SQLITE_IOCAP_ATOMIC2K 0x00000008 416#define SQLITE_IOCAP_ATOMIC4K 0x00000010 417#define SQLITE_IOCAP_ATOMIC8K 0x00000020 418#define SQLITE_IOCAP_ATOMIC16K 0x00000040 419#define SQLITE_IOCAP_ATOMIC32K 0x00000080 420#define SQLITE_IOCAP_ATOMIC64K 0x00000100 421#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 422#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 423 424/* 425** CAPI3REF: File Locking Levels {F10250} 426** 427** {F10251} SQLite uses one of the following integer values as the second 428** argument to calls it makes to the xLock() and xUnlock() methods 429** of an [sqlite3_io_methods] object. {END} 430*/ 431#define SQLITE_LOCK_NONE 0 432#define SQLITE_LOCK_SHARED 1 433#define SQLITE_LOCK_RESERVED 2 434#define SQLITE_LOCK_PENDING 3 435#define SQLITE_LOCK_EXCLUSIVE 4 436 437/* 438** CAPI3REF: Synchronization Type Flags {F10260} 439** 440** {F10261} When SQLite invokes the xSync() method of an 441** [sqlite3_io_methods] object it uses a combination of the 442** these integer values as the second argument. 443** 444** {F10262} When the SQLITE_SYNC_DATAONLY flag is used, it means that the 445** sync operation only needs to flush data to mass storage. Inode 446** information need not be flushed. {F10263} The SQLITE_SYNC_NORMAL means 447** to use normal fsync() semantics. {F10264} The SQLITE_SYNC_FULL flag means 448** to use Mac OS-X style fullsync instead of fsync(). 449*/ 450#define SQLITE_SYNC_NORMAL 0x00002 451#define SQLITE_SYNC_FULL 0x00003 452#define SQLITE_SYNC_DATAONLY 0x00010 453 454 455/* 456** CAPI3REF: OS Interface Open File Handle {F11110} 457** 458** An [sqlite3_file] object represents an open file in the OS 459** interface layer. Individual OS interface implementations will 460** want to subclass this object by appending additional fields 461** for their own use. The pMethods entry is a pointer to an 462** [sqlite3_io_methods] object that defines methods for performing 463** I/O operations on the open file. 464*/ 465typedef struct sqlite3_file sqlite3_file; 466struct sqlite3_file { 467 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 468}; 469 470/* 471** CAPI3REF: OS Interface File Virtual Methods Object {F11120} 472** 473** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to 474** an instance of the this object. This object defines the 475** methods used to perform various operations against the open file. 476** 477** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 478** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 479* The second choice is an 480** OS-X style fullsync. The SQLITE_SYNC_DATA flag may be ORed in to 481** indicate that only the data of the file and not its inode needs to be 482** synced. 483** 484** The integer values to xLock() and xUnlock() are one of 485** <ul> 486** <li> [SQLITE_LOCK_NONE], 487** <li> [SQLITE_LOCK_SHARED], 488** <li> [SQLITE_LOCK_RESERVED], 489** <li> [SQLITE_LOCK_PENDING], or 490** <li> [SQLITE_LOCK_EXCLUSIVE]. 491** </ul> 492** xLock() increases the lock. xUnlock() decreases the lock. 493** The xCheckReservedLock() method looks 494** to see if any database connection, either in this 495** process or in some other process, is holding an RESERVED, 496** PENDING, or EXCLUSIVE lock on the file. It returns true 497** if such a lock exists and false if not. 498** 499** The xFileControl() method is a generic interface that allows custom 500** VFS implementations to directly control an open file using the 501** [sqlite3_file_control()] interface. The second "op" argument 502** is an integer opcode. The third 503** argument is a generic pointer which is intended to be a pointer 504** to a structure that may contain arguments or space in which to 505** write return values. Potential uses for xFileControl() might be 506** functions to enable blocking locks with timeouts, to change the 507** locking strategy (for example to use dot-file locks), to inquire 508** about the status of a lock, or to break stale locks. The SQLite 509** core reserves opcodes less than 100 for its own use. 510** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. 511** Applications that define a custom xFileControl method should use opcodes 512** greater than 100 to avoid conflicts. 513** 514** The xSectorSize() method returns the sector size of the 515** device that underlies the file. The sector size is the 516** minimum write that can be performed without disturbing 517** other bytes in the file. The xDeviceCharacteristics() 518** method returns a bit vector describing behaviors of the 519** underlying device: 520** 521** <ul> 522** <li> [SQLITE_IOCAP_ATOMIC] 523** <li> [SQLITE_IOCAP_ATOMIC512] 524** <li> [SQLITE_IOCAP_ATOMIC1K] 525** <li> [SQLITE_IOCAP_ATOMIC2K] 526** <li> [SQLITE_IOCAP_ATOMIC4K] 527** <li> [SQLITE_IOCAP_ATOMIC8K] 528** <li> [SQLITE_IOCAP_ATOMIC16K] 529** <li> [SQLITE_IOCAP_ATOMIC32K] 530** <li> [SQLITE_IOCAP_ATOMIC64K] 531** <li> [SQLITE_IOCAP_SAFE_APPEND] 532** <li> [SQLITE_IOCAP_SEQUENTIAL] 533** </ul> 534** 535** The SQLITE_IOCAP_ATOMIC property means that all writes of 536** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 537** mean that writes of blocks that are nnn bytes in size and 538** are aligned to an address which is an integer multiple of 539** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 540** that when data is appended to a file, the data is appended 541** first then the size of the file is extended, never the other 542** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 543** information is written to disk in the same order as calls 544** to xWrite(). 545*/ 546typedef struct sqlite3_io_methods sqlite3_io_methods; 547struct sqlite3_io_methods { 548 int iVersion; 549 int (*xClose)(sqlite3_file*); 550 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 551 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 552 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 553 int (*xSync)(sqlite3_file*, int flags); 554 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 555 int (*xLock)(sqlite3_file*, int); 556 int (*xUnlock)(sqlite3_file*, int); 557 int (*xCheckReservedLock)(sqlite3_file*); 558 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 559 int (*xSectorSize)(sqlite3_file*); 560 int (*xDeviceCharacteristics)(sqlite3_file*); 561 /* Additional methods may be added in future releases */ 562}; 563 564/* 565** CAPI3REF: Standard File Control Opcodes {F11310} 566** 567** These integer constants are opcodes for the xFileControl method 568** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()] 569** interface. 570** 571** {F11311} The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 572** opcode cases the xFileControl method to write the current state of 573** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 574** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 575** into an integer that the pArg argument points to. {F11312} This capability 576** is used during testing and only needs to be supported when SQLITE_TEST 577** is defined. 578*/ 579#define SQLITE_FCNTL_LOCKSTATE 1 580 581/* 582** CAPI3REF: Mutex Handle {F17110} 583** 584** The mutex module within SQLite defines [sqlite3_mutex] to be an 585** abstract type for a mutex object. {F17111} The SQLite core never looks 586** at the internal representation of an [sqlite3_mutex]. {END} It only 587** deals with pointers to the [sqlite3_mutex] object. 588** 589** Mutexes are created using [sqlite3_mutex_alloc()]. 590*/ 591typedef struct sqlite3_mutex sqlite3_mutex; 592 593/* 594** CAPI3REF: OS Interface Object {F11140} 595** 596** An instance of this object defines the interface between the 597** SQLite core and the underlying operating system. The "vfs" 598** in the name of the object stands for "virtual file system". 599** 600** The iVersion field is initially 1 but may be larger for future 601** versions of SQLite. Additional fields may be appended to this 602** object when the iVersion value is increased. 603** 604** The szOsFile field is the size of the subclassed [sqlite3_file] 605** structure used by this VFS. mxPathname is the maximum length of 606** a pathname in this VFS. 607** 608** Registered vfs modules are kept on a linked list formed by 609** the pNext pointer. The [sqlite3_vfs_register()] 610** and [sqlite3_vfs_unregister()] interfaces manage this list 611** in a thread-safe way. The [sqlite3_vfs_find()] interface 612** searches the list. 613** 614** The pNext field is the only fields in the sqlite3_vfs 615** structure that SQLite will ever modify. SQLite will only access 616** or modify this field while holding a particular static mutex. 617** The application should never modify anything within the sqlite3_vfs 618** object once the object has been registered. 619** 620** The zName field holds the name of the VFS module. The name must 621** be unique across all VFS modules. 622** 623** {F11141} SQLite will guarantee that the zFilename string passed to 624** xOpen() is a full pathname as generated by xFullPathname() and 625** that the string will be valid and unchanged until xClose() is 626** called. {END} So the [sqlite3_file] can store a pointer to the 627** filename if it needs to remember the filename for some reason. 628** 629** {F11142} The flags argument to xOpen() includes all bits set in 630** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 631** or [sqlite3_open16()] is used, then flags includes at least 632** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. {END} 633** If xOpen() opens a file read-only then it sets *pOutFlags to 634** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be 635** set. 636** 637** {F11143} SQLite will also add one of the following flags to the xOpen() 638** call, depending on the object being opened: 639** 640** <ul> 641** <li> [SQLITE_OPEN_MAIN_DB] 642** <li> [SQLITE_OPEN_MAIN_JOURNAL] 643** <li> [SQLITE_OPEN_TEMP_DB] 644** <li> [SQLITE_OPEN_TEMP_JOURNAL] 645** <li> [SQLITE_OPEN_TRANSIENT_DB] 646** <li> [SQLITE_OPEN_SUBJOURNAL] 647** <li> [SQLITE_OPEN_MASTER_JOURNAL] 648** </ul> {END} 649** 650** The file I/O implementation can use the object type flags to 651** changes the way it deals with files. For example, an application 652** that does not care about crash recovery or rollback, might make 653** the open of a journal file a no-op. Writes to this journal are 654** also a no-op. Any attempt to read the journal return SQLITE_IOERR. 655** Or the implementation might recognize the a database file will 656** be doing page-aligned sector reads and writes in a random order 657** and set up its I/O subsystem accordingly. 658** 659** {F11144} SQLite might also add one of the following flags to the xOpen 660** method: 661** 662** <ul> 663** <li> [SQLITE_OPEN_DELETEONCLOSE] 664** <li> [SQLITE_OPEN_EXCLUSIVE] 665** </ul> 666** 667** {F11145} The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 668** deleted when it is closed. {F11146} The [SQLITE_OPEN_DELETEONCLOSE] 669** will be set for TEMP databases, journals and for subjournals. 670** {F11147} The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened 671** for exclusive access. This flag is set for all files except 672** for the main database file. {END} 673** 674** {F11148} At least szOsFile bytes of memory is allocated by SQLite 675** to hold the [sqlite3_file] structure passed as the third 676** argument to xOpen. {END} The xOpen method does not have to 677** allocate the structure; it should just fill it in. 678** 679** {F11149} The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 680** to test for the existance of a file, 681** or [SQLITE_ACCESS_READWRITE] to test to see 682** if a file is readable and writable, or [SQLITE_ACCESS_READ] 683** to test to see if a file is at least readable. {END} The file can be a 684** directory. 685** 686** {F11150} SQLite will always allocate at least mxPathname+1 byte for 687** the output buffers for xGetTempname and xFullPathname. {F11151} The exact 688** size of the output buffer is also passed as a parameter to both 689** methods. {END} If the output buffer is not large enough, SQLITE_CANTOPEN 690** should be returned. As this is handled as a fatal error by SQLite, 691** vfs implementations should endeavor to prevent this by setting 692** mxPathname to a sufficiently large value. 693** 694** The xRandomness(), xSleep(), and xCurrentTime() interfaces 695** are not strictly a part of the filesystem, but they are 696** included in the VFS structure for completeness. 697** The xRandomness() function attempts to return nBytes bytes 698** of good-quality randomness into zOut. The return value is 699** the actual number of bytes of randomness obtained. The 700** xSleep() method cause the calling thread to sleep for at 701** least the number of microseconds given. The xCurrentTime() 702** method returns a Julian Day Number for the current date and 703** time. 704*/ 705typedef struct sqlite3_vfs sqlite3_vfs; 706struct sqlite3_vfs { 707 int iVersion; /* Structure version number */ 708 int szOsFile; /* Size of subclassed sqlite3_file */ 709 int mxPathname; /* Maximum file pathname length */ 710 sqlite3_vfs *pNext; /* Next registered VFS */ 711 const char *zName; /* Name of this virtual file system */ 712 void *pAppData; /* Pointer to application-specific data */ 713 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 714 int flags, int *pOutFlags); 715 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 716 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags); 717 int (*xGetTempname)(sqlite3_vfs*, int nOut, char *zOut); 718 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 719 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 720 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 721 void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol); 722 void (*xDlClose)(sqlite3_vfs*, void*); 723 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 724 int (*xSleep)(sqlite3_vfs*, int microseconds); 725 int (*xCurrentTime)(sqlite3_vfs*, double*); 726 /* New fields may be appended in figure versions. The iVersion 727 ** value will increment whenever this happens. */ 728}; 729 730/* 731** CAPI3REF: Flags for the xAccess VFS method {F11190} 732** 733** {F11191} These integer constants can be used as the third parameter to 734** the xAccess method of an [sqlite3_vfs] object. {END} They determine 735** the kind of what kind of permissions the xAccess method is 736** looking for. {F11192} With SQLITE_ACCESS_EXISTS, the xAccess method 737** simply checks to see if the file exists. {F11193} With 738** SQLITE_ACCESS_READWRITE, the xAccess method checks to see 739** if the file is both readable and writable. {F11194} With 740** SQLITE_ACCESS_READ the xAccess method 741** checks to see if the file is readable. 742*/ 743#define SQLITE_ACCESS_EXISTS 0 744#define SQLITE_ACCESS_READWRITE 1 745#define SQLITE_ACCESS_READ 2 746 747/* 748** CAPI3REF: Enable Or Disable Extended Result Codes {F12200} 749** 750** {F12201} The sqlite3_extended_result_codes() routine enables or disables the 751** [SQLITE_IOERR_READ | extended result codes] feature on a database 752** connection if its 2nd parameter is 753** non-zero or zero, respectively. {F12202} 754** By default, SQLite API routines return one of only 26 integer 755** [SQLITE_OK | result codes]. {F12203} When extended result codes 756** are enabled by this routine, the repetoire of result codes can be 757** much larger and can (hopefully) provide more detailed information 758** about the cause of an error. 759** 760** {F12204} The second argument is a boolean value that turns extended result 761** codes on and off. {F12205} Extended result codes are off by default for 762** backwards compatibility with older versions of SQLite. 763*/ 764int sqlite3_extended_result_codes(sqlite3*, int onoff); 765 766/* 767** CAPI3REF: Last Insert Rowid {F12220} 768** 769** {F12221} Each entry in an SQLite table has a unique 64-bit signed 770** integer key called the "rowid". {F12222} The rowid is always available 771** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 772** names are not also used by explicitly declared columns. {F12223} If 773** the table has a column of type INTEGER PRIMARY KEY then that column 774** is another an alias for the rowid. 775** 776** {F12224} This routine returns the rowid of the most recent 777** successful INSERT into the database from the database connection 778** shown in the first argument. {F12225} If no successful inserts 779** have ever occurred on this database connection, zero is returned. 780** 781** {F12226} If an INSERT occurs within a trigger, then the rowid of the 782** inserted row is returned by this routine as long as the trigger 783** is running. {F12227} But once the trigger terminates, the value returned 784** by this routine reverts to the last value inserted before the 785** trigger fired. 786** 787** {F12228} An INSERT that fails due to a constraint violation is not a 788** successful insert and does not change the value returned by this 789** routine. {F12229} Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 790** and INSERT OR ABORT make no changes to the return value of this 791** routine when their insertion fails. {F12231} When INSERT OR REPLACE 792** encounters a constraint violation, it does not fail. The 793** INSERT continues to completion after deleting rows that caused 794** the constraint problem so INSERT OR REPLACE will always change 795** the return value of this interface. 796** 797** {UF12232} If another thread does a new insert on the same database connection 798** while this routine is running and thus changes the last insert rowid, 799** then the return value of this routine is undefined. 800*/ 801sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 802 803/* 804** CAPI3REF: Count The Number Of Rows Modified {F12240} 805** 806** {F12241} This function returns the number of database rows that were changed 807** or inserted or deleted by the most recently completed SQL statement 808** on the connection specified by the first parameter. {F12242} Only 809** changes that are directly specified by the INSERT, UPDATE, or 810** DELETE statement are counted. Auxiliary changes caused by 811** triggers are not counted. {F12243} Use the [sqlite3_total_changes()] function 812** to find the total number of changes including changes caused by triggers. 813** 814** {F12244} Within the body of a trigger, the sqlite3_changes() interface 815** can be called to find the number of 816** changes in the most recently completed INSERT, UPDATE, or DELETE 817** statement within the body of the same trigger. 818** 819** {F12245} All changes are counted, even if they are later undone by a 820** ROLLBACK or ABORT. {F12246} Except, changes associated with creating and 821** dropping tables are not counted. 822** 823** {F12247} If a callback invokes [sqlite3_exec()] or [sqlite3_step()] 824** recursively, then the changes in the inner, recursive call are 825** counted together with the changes in the outer call. 826** 827** {F12248} SQLite implements the command "DELETE FROM table" without 828** a WHERE clause by dropping and recreating the table. (This is much 829** faster than going through and deleting individual elements from the 830** table.) Because of this optimization, the change count for 831** "DELETE FROM table" will be zero regardless of the number of elements 832** that were originally in the table. {F12251} To get an accurate count 833** of the number of rows deleted, use 834** "DELETE FROM table WHERE 1" instead. 835** 836** {UF12252} If another thread makes changes on the same database connection 837** while this routine is running then the return value of this routine 838** is undefined. 839*/ 840int sqlite3_changes(sqlite3*); 841 842/* 843** CAPI3REF: Total Number Of Rows Modified {F12260} 844*** 845** {F12261} This function returns the number of database rows that have been 846** modified by INSERT, UPDATE or DELETE statements since the database handle 847** was opened. {F12262} The count includes UPDATE, INSERT and DELETE 848** statements executed as part of trigger programs. {F12263} All changes 849** are counted as soon as the statement that makes them is completed 850** (when the statement handle is passed to [sqlite3_reset()] or 851** [sqlite3_finalize()]). {END} 852** 853** See also the [sqlite3_change()] interface. 854** 855** {F12265} SQLite implements the command "DELETE FROM table" without 856** a WHERE clause by dropping and recreating the table. (This is much 857** faster than going 858** through and deleting individual elements form the table.) Because of 859** this optimization, the change count for "DELETE FROM table" will be 860** zero regardless of the number of elements that were originally in the 861** table. To get an accurate count of the number of rows deleted, use 862** "DELETE FROM table WHERE 1" instead. 863** 864** {U12264} If another thread makes changes on the same database connection 865** while this routine is running then the return value of this routine 866** is undefined. {END} 867*/ 868int sqlite3_total_changes(sqlite3*); 869 870/* 871** CAPI3REF: Interrupt A Long-Running Query {F12270} 872** 873** {F12271} This function causes any pending database operation to abort and 874** return at its earliest opportunity. {END} This routine is typically 875** called in response to a user action such as pressing "Cancel" 876** or Ctrl-C where the user wants a long query operation to halt 877** immediately. 878** 879** {F12272} It is safe to call this routine from a thread different from the 880** thread that is currently running the database operation. {U12273} But it 881** is not safe to call this routine with a database connection that 882** is closed or might close before sqlite3_interrupt() returns. 883** 884** If an SQL is very nearly finished at the time when sqlite3_interrupt() 885** is called, then it might not have an opportunity to be interrupted. 886** It might continue to completion. 887** {F12274} The SQL operation that is interrupted will return 888** [SQLITE_INTERRUPT]. {F12275} If the interrupted SQL operation is an 889** INSERT, UPDATE, or DELETE that is inside an explicit transaction, 890** then the entire transaction will be rolled back automatically. 891** {F12276} A call to sqlite3_interrupt() has no effect on SQL statements 892** that are started after sqlite3_interrupt() returns. 893*/ 894void sqlite3_interrupt(sqlite3*); 895 896/* 897** CAPI3REF: Determine If An SQL Statement Is Complete {F10510} 898** 899** These routines are useful for command-line input to determine if the 900** currently entered text seems to form complete a SQL statement or 901** if additional input is needed before sending the text into 902** SQLite for parsing. These routines return true if the input string 903** appears to be a complete SQL statement. A statement is judged to be 904** complete if it ends with a semicolon and is not a fragment of a 905** CREATE TRIGGER statement. These routines do not parse the SQL and 906** so will not detect syntactically incorrect SQL. 907** 908** {F10511} These functions return true if the given input string 909** ends with a semicolon optionally followed by whitespace or 910** comments. {F10512} For sqlite3_complete(), 911** the parameter must be a zero-terminated UTF-8 string. {F10513} For 912** sqlite3_complete16(), a zero-terminated machine byte order UTF-16 string 913** is required. {F10514} These routines return false if the terminal 914** semicolon is within a comment, a string literal or a quoted identifier 915** (in other words if the final semicolon is not really a separate token 916** but part of a larger token) or if the final semicolon is 917** in between the BEGIN and END keywords of a CREATE TRIGGER statement. 918** {END} 919*/ 920int sqlite3_complete(const char *sql); 921int sqlite3_complete16(const void *sql); 922 923/* 924** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {F12310} 925** 926** {F12311} This routine identifies a callback function that might be 927** invoked whenever an attempt is made to open a database table 928** that another thread or process has locked. 929** {F12312} If the busy callback is NULL, then [SQLITE_BUSY] 930** or [SQLITE_IOERR_BLOCKED] 931** is returned immediately upon encountering the lock. 932** {F12313} If the busy callback is not NULL, then the 933** callback will be invoked with two arguments. {F12314} The 934** first argument to the handler is a copy of the void* pointer which 935** is the third argument to this routine. {F12315} The second argument to 936** the handler is the number of times that the busy handler has 937** been invoked for this locking event. {F12316} If the 938** busy callback returns 0, then no additional attempts are made to 939** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. 940** {F12317} If the callback returns non-zero, then another attempt 941** is made to open the database for reading and the cycle repeats. 942** 943** The presence of a busy handler does not guarantee that 944** it will be invoked when there is lock contention. {F12319} 945** If SQLite determines that invoking the busy handler could result in 946** a deadlock, it will go ahead and return [SQLITE_BUSY] or 947** [SQLITE_IOERR_BLOCKED] instead of invoking the 948** busy handler. {END} 949** Consider a scenario where one process is holding a read lock that 950** it is trying to promote to a reserved lock and 951** a second process is holding a reserved lock that it is trying 952** to promote to an exclusive lock. The first process cannot proceed 953** because it is blocked by the second and the second process cannot 954** proceed because it is blocked by the first. If both processes 955** invoke the busy handlers, neither will make any progress. Therefore, 956** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 957** will induce the first process to release its read lock and allow 958** the second process to proceed. 959** 960** {F12321} The default busy callback is NULL. {END} 961** 962** {F12322} The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] 963** when SQLite is in the middle of a large transaction where all the 964** changes will not fit into the in-memory cache. {F12323} SQLite will 965** already hold a RESERVED lock on the database file, but it needs 966** to promote this lock to EXCLUSIVE so that it can spill cache 967** pages into the database file without harm to concurrent 968** readers. {F12324} If it is unable to promote the lock, then the in-memory 969** cache will be left in an inconsistent state and so the error 970** code is promoted from the relatively benign [SQLITE_BUSY] to 971** the more severe [SQLITE_IOERR_BLOCKED]. {F12325} This error code promotion 972** forces an automatic rollback of the changes. {END} See the 973** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError"> 974** CorruptionFollowingBusyError</a> wiki page for a discussion of why 975** this is important. 976** 977** {F12326} Sqlite is re-entrant, so the busy handler may start a new 978** query. {END} (It is not clear why anyone would every want to do this, 979** but it is allowed, in theory.) {U12327} But the busy handler may not 980** close the database. Closing the database from a busy handler will delete 981** data structures out from under the executing query and will 982** probably result in a segmentation fault or other runtime error. {END} 983** 984** {F12328} There can only be a single busy handler defined for each database 985** connection. Setting a new busy handler clears any previous one. 986** {F12329} Note that calling [sqlite3_busy_timeout()] will also set or clear 987** the busy handler. 988** 989** {F12331} When operating in [sqlite3_enable_shared_cache | shared cache mode], 990** only a single busy handler can be defined for each database file. 991** So if two database connections share a single cache, then changing 992** the busy handler on one connection will also change the busy 993** handler in the other connection. {F12332} The busy handler is invoked 994** in the thread that was running when the lock contention occurs. 995*/ 996int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 997 998/* 999** CAPI3REF: Set A Busy Timeout {F12340} 1000** 1001** {F12341} This routine sets a [sqlite3_busy_handler | busy handler] 1002** that sleeps for a while when a 1003** table is locked. {F12342} The handler will sleep multiple times until 1004** at least "ms" milliseconds of sleeping have been done. {F12343} After 1005** "ms" milliseconds of sleeping, the handler returns 0 which 1006** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. 1007** 1008** {F12344} Calling this routine with an argument less than or equal to zero 1009** turns off all busy handlers. 1010** 1011** {F12345} There can only be a single busy handler for a particular database 1012** connection. If another busy handler was defined 1013** (using [sqlite3_busy_handler()]) prior to calling 1014** this routine, that other busy handler is cleared. 1015*/ 1016int sqlite3_busy_timeout(sqlite3*, int ms); 1017 1018/* 1019** CAPI3REF: Convenience Routines For Running Queries {F12370} 1020** 1021** This next routine is a convenience wrapper around [sqlite3_exec()]. 1022** {F12371} Instead of invoking a user-supplied callback for each row of the 1023** result, this routine remembers each row of the result in memory 1024** obtained from [sqlite3_malloc()], then returns all of the result after the 1025** query has finished. {F12372} 1026** 1027** As an example, suppose the query result where this table: 1028** 1029** <blockquote><pre> 1030** Name | Age 1031** ----------------------- 1032** Alice | 43 1033** Bob | 28 1034** Cindy | 21 1035** </pre></blockquote> 1036** 1037** If the 3rd argument were &azResult then after the function returns 1038** azResult will contain the following data: 1039** 1040** <blockquote><pre> 1041** azResult[0] = "Name"; 1042** azResult[1] = "Age"; 1043** azResult[2] = "Alice"; 1044** azResult[3] = "43"; 1045** azResult[4] = "Bob"; 1046** azResult[5] = "28"; 1047** azResult[6] = "Cindy"; 1048** azResult[7] = "21"; 1049** </pre></blockquote> 1050** 1051** Notice that there is an extra row of data containing the column 1052** headers. But the *nrow return value is still 3. *ncolumn is 1053** set to 2. In general, the number of values inserted into azResult 1054** will be ((*nrow) + 1)*(*ncolumn). 1055** 1056** {U12374} After the calling function has finished using the result, it should 1057** pass the result data pointer to sqlite3_free_table() in order to 1058** release the memory that was malloc-ed. Because of the way the 1059** [sqlite3_malloc()] happens, the calling function must not try to call 1060** [sqlite3_free()] directly. Only [sqlite3_free_table()] is able to release 1061** the memory properly and safely. {END} 1062** 1063** {F12373} The return value of this routine is the same as 1064** from [sqlite3_exec()]. 1065*/ 1066int sqlite3_get_table( 1067 sqlite3*, /* An open database */ 1068 const char *sql, /* SQL to be executed */ 1069 char ***resultp, /* Result written to a char *[] that this points to */ 1070 int *nrow, /* Number of result rows written here */ 1071 int *ncolumn, /* Number of result columns written here */ 1072 char **errmsg /* Error msg written here */ 1073); 1074void sqlite3_free_table(char **result); 1075 1076/* 1077** CAPI3REF: Formatted String Printing Functions {F17400} 1078** 1079** These routines are workalikes of the "printf()" family of functions 1080** from the standard C library. 1081** 1082** {F17401} The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 1083** results into memory obtained from [sqlite3_malloc()]. 1084** {U17402} The strings returned by these two routines should be 1085** released by [sqlite3_free()]. {F17403} Both routines return a 1086** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 1087** memory to hold the resulting string. 1088** 1089** {F17404} In sqlite3_snprintf() routine is similar to "snprintf()" from 1090** the standard C library. The result is written into the 1091** buffer supplied as the second parameter whose size is given by 1092** the first parameter. {END} Note that the order of the 1093** first two parameters is reversed from snprintf(). This is an 1094** historical accident that cannot be fixed without breaking 1095** backwards compatibility. {F17405} Note also that sqlite3_snprintf() 1096** returns a pointer to its buffer instead of the number of 1097** characters actually written into the buffer. {END} We admit that 1098** the number of characters written would be a more useful return 1099** value but we cannot change the implementation of sqlite3_snprintf() 1100** now without breaking compatibility. 1101** 1102** {F17406} As long as the buffer size is greater than zero, sqlite3_snprintf() 1103** guarantees that the buffer is always zero-terminated. {F17407} The first 1104** parameter "n" is the total size of the buffer, including space for 1105** the zero terminator. {END} So the longest string that can be completely 1106** written will be n-1 characters. 1107** 1108** These routines all implement some additional formatting 1109** options that are useful for constructing SQL statements. 1110** All of the usual printf formatting options apply. In addition, there 1111** is are "%q", "%Q", and "%z" options. 1112** 1113** {F17410} The %q option works like %s in that it substitutes a null-terminated 1114** string from the argument list. But %q also doubles every '\'' character. 1115** %q is designed for use inside a string literal. {END} By doubling each '\'' 1116** character it escapes that character and allows it to be inserted into 1117** the string. 1118** 1119** For example, so some string variable contains text as follows: 1120** 1121** <blockquote><pre> 1122** char *zText = "It's a happy day!"; 1123** </pre></blockquote> 1124** 1125** One can use this text in an SQL statement as follows: 1126** 1127** <blockquote><pre> 1128** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 1129** sqlite3_exec(db, zSQL, 0, 0, 0); 1130** sqlite3_free(zSQL); 1131** </pre></blockquote> 1132** 1133** Because the %q format string is used, the '\'' character in zText 1134** is escaped and the SQL generated is as follows: 1135** 1136** <blockquote><pre> 1137** INSERT INTO table1 VALUES('It''s a happy day!') 1138** </pre></blockquote> 1139** 1140** This is correct. Had we used %s instead of %q, the generated SQL 1141** would have looked like this: 1142** 1143** <blockquote><pre> 1144** INSERT INTO table1 VALUES('It's a happy day!'); 1145** </pre></blockquote> 1146** 1147** This second example is an SQL syntax error. As a general rule you 1148** should always use %q instead of %s when inserting text into a string 1149** literal. 1150** 1151** {F17411} The %Q option works like %q except it also adds single quotes around 1152** the outside of the total string. Or if the parameter in the argument 1153** list is a NULL pointer, %Q substitutes the text "NULL" (without single 1154** quotes) in place of the %Q option. {END} So, for example, one could say: 1155** 1156** <blockquote><pre> 1157** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 1158** sqlite3_exec(db, zSQL, 0, 0, 0); 1159** sqlite3_free(zSQL); 1160** </pre></blockquote> 1161** 1162** The code above will render a correct SQL statement in the zSQL 1163** variable even if the zText variable is a NULL pointer. 1164** 1165** {F17412} The "%z" formatting option works exactly like "%s" with the 1166** addition that after the string has been read and copied into 1167** the result, [sqlite3_free()] is called on the input string. {END} 1168*/ 1169char *sqlite3_mprintf(const char*,...); 1170char *sqlite3_vmprintf(const char*, va_list); 1171char *sqlite3_snprintf(int,char*,const char*, ...); 1172 1173/* 1174** CAPI3REF: Memory Allocation Subsystem {F17300} 1175** 1176** {F17301} The SQLite core uses these three routines for all of its own 1177** internal memory allocation needs. {END} "Core" in the previous sentence 1178** does not include operating-system specific VFS implementation. The 1179** windows VFS uses native malloc and free for some operations. 1180** 1181** {F17302} The sqlite3_malloc() routine returns a pointer to a block 1182** of memory at least N bytes in length, where N is the parameter. 1183** {F17303} If sqlite3_malloc() is unable to obtain sufficient free 1184** memory, it returns a NULL pointer. {F17304} If the parameter N to 1185** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 1186** a NULL pointer. 1187** 1188** {F17305} Calling sqlite3_free() with a pointer previously returned 1189** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 1190** that it might be reused. {F17306} The sqlite3_free() routine is 1191** a no-op if is called with a NULL pointer. Passing a NULL pointer 1192** to sqlite3_free() is harmless. {U17307} After being freed, memory 1193** should neither be read nor written. Even reading previously freed 1194** memory might result in a segmentation fault or other severe error. 1195** {U17309} Memory corruption, a segmentation fault, or other severe error 1196** might result if sqlite3_free() is called with a non-NULL pointer that 1197** was not obtained from sqlite3_malloc() or sqlite3_free(). 1198** 1199** {F17310} The sqlite3_realloc() interface attempts to resize a 1200** prior memory allocation to be at least N bytes, where N is the 1201** second parameter. The memory allocation to be resized is the first 1202** parameter. {F17311} If the first parameter to sqlite3_realloc() 1203** is a NULL pointer then its behavior is identical to calling 1204** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 1205** {F17312} If the second parameter to sqlite3_realloc() is zero or 1206** negative then the behavior is exactly the same as calling 1207** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 1208** {F17313} Sqlite3_realloc() returns a pointer to a memory allocation 1209** of at least N bytes in size or NULL if sufficient memory is unavailable. 1210** {F17314} If M is the size of the prior allocation, then min(N,M) bytes 1211** of the prior allocation are copied into the beginning of buffer returned 1212** by sqlite3_realloc() and the prior allocation is freed. 1213** {F17315} If sqlite3_realloc() returns NULL, then the prior allocation 1214** is not freed. 1215** 1216** {F17316} The memory returned by sqlite3_malloc() and sqlite3_realloc() 1217** is always aligned to at least an 8 byte boundary. {END} 1218** 1219** {F17381} The default implementation 1220** of the memory allocation subsystem uses the malloc(), realloc() 1221** and free() provided by the standard C library. {F17382} However, if 1222** SQLite is compiled with the following C preprocessor macro 1223** 1224** <blockquote> SQLITE_MEMORY_SIZE=<i>NNN</i> </blockquote> 1225** 1226** where <i>NNN</i> is an integer, then SQLite create a static 1227** array of at least <i>NNN</i> bytes in size and use that array 1228** for all of its dynamic memory allocation needs. {END} Additional 1229** memory allocator options may be added in future releases. 1230** 1231** In SQLite version 3.5.0 and 3.5.1, it was possible to define 1232** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 1233** implementation of these routines to be omitted. That capability 1234** is no longer provided. Only built-in memory allocators can be 1235** used. 1236** 1237** The windows OS interface layer calls 1238** the system malloc() and free() directly when converting 1239** filenames between the UTF-8 encoding used by SQLite 1240** and whatever filename encoding is used by the particular windows 1241** installation. Memory allocation errors are detected, but 1242** they are reported back as [SQLITE_CANTOPEN] or 1243** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 1244*/ 1245void *sqlite3_malloc(int); 1246void *sqlite3_realloc(void*, int); 1247void sqlite3_free(void*); 1248 1249/* 1250** CAPI3REF: Memory Allocator Statistics {F17370} 1251** 1252** In addition to the basic three allocation routines 1253** [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()], 1254** the memory allocation subsystem included with the SQLite 1255** sources provides the interfaces shown here. 1256** 1257** {F17371} The sqlite3_memory_used() routine returns the 1258** number of bytes of memory currently outstanding (malloced but not freed). 1259** {F17372} The value returned by sqlite3_memory_used() includes 1260** any overhead added by SQLite, but not overhead added by the 1261** library malloc() that backs the sqlite3_malloc() implementation. 1262** {F17373} The sqlite3_memory_highwater() routines returns the 1263** maximum number of bytes that have been outstanding at any time 1264** since the highwater mark was last reset. 1265** {F17374} The byte count returned by sqlite3_memory_highwater() 1266** uses the same byte counting rules as sqlite3_memory_used(). {END} 1267** In other words, overhead added internally by SQLite is counted, 1268** but overhead from the underlying system malloc is not. 1269** {F17375} If the parameter to sqlite3_memory_highwater() is true, 1270** then the highwater mark is reset to the current value of 1271** sqlite3_memory_used() and the prior highwater mark (before the 1272** reset) is returned. {F17376} If the parameter to 1273** sqlite3_memory_highwater() is zero, then the highwater mark is 1274** unchanged. 1275*/ 1276sqlite3_int64 sqlite3_memory_used(void); 1277sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 1278 1279/* 1280** CAPI3REF: Compile-Time Authorization Callbacks {F12500} 1281** 1282** {F12501} This routine registers a authorizer callback with a particular 1283** database connection, supplied in the first argument. {F12502} 1284** The authorizer callback is invoked as SQL statements are being compiled 1285** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 1286** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. {F12503} At various 1287** points during the compilation process, as logic is being created 1288** to perform various actions, the authorizer callback is invoked to 1289** see if those actions are allowed. The authorizer callback should 1290** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the 1291** specific action but allow the SQL statement to continue to be 1292** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 1293** rejected with an error. {F12504} If the authorizer callback returns 1294** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 1295** then [sqlite3_prepare_v2()] or equivalent call that triggered 1296** the authorizer shall 1297** fail with an SQLITE_ERROR error code and an appropriate error message. {END} 1298** 1299** When the callback returns [SQLITE_OK], that means the operation 1300** requested is ok. {F12505} When the callback returns [SQLITE_DENY], the 1301** [sqlite3_prepare_v2()] or equivalent call that triggered the 1302** authorizer shall fail 1303** with an SQLITE_ERROR error code and an error message explaining that 1304** access is denied. {F12506} If the authorizer code (the 2nd parameter 1305** to the authorizer callback is anything other than [SQLITE_READ], then 1306** a return of [SQLITE_IGNORE] has the same effect as [SQLITE_DENY]. 1307** If the authorizer code is [SQLITE_READ] and the callback returns 1308** [SQLITE_IGNORE] then the prepared statement is constructed to 1309** insert a NULL value in place of the table column that would have 1310** been read if [SQLITE_OK] had been returned. {END} 1311** 1312** {F12510} The first parameter to the authorizer callback is a copy of 1313** the third parameter to the sqlite3_set_authorizer() interface. 1314** {F12511} The second parameter to the callback is an integer 1315** [SQLITE_COPY | action code] that specifies the particular action 1316** to be authorized. {END} The available action codes are 1317** [SQLITE_COPY | documented separately]. {F12512} The third through sixth 1318** parameters to the callback are zero-terminated strings that contain 1319** additional details about the action to be authorized. {END} 1320** 1321** An authorizer is used when preparing SQL statements from an untrusted 1322** source, to ensure that the SQL statements do not try to access data 1323** that they are not allowed to see, or that they do not try to 1324** execute malicious statements that damage the database. For 1325** example, an application may allow a user to enter arbitrary 1326** SQL queries for evaluation by a database. But the application does 1327** not want the user to be able to make arbitrary changes to the 1328** database. An authorizer could then be put in place while the 1329** user-entered SQL is being prepared that disallows everything 1330** except SELECT statements. 1331** 1332** {F12520} Only a single authorizer can be in place on a database connection 1333** at a time. Each call to sqlite3_set_authorizer overrides the 1334** previous call. {F12521} A NULL authorizer means that no authorization 1335** callback is invoked. {F12522} The default authorizer is NULL. {END} 1336** 1337** Note that the authorizer callback is invoked only during 1338** [sqlite3_prepare()] or its variants. {F12523} Authorization is not 1339** performed during statement evaluation in [sqlite3_step()]. {END} 1340*/ 1341int sqlite3_set_authorizer( 1342 sqlite3*, 1343 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 1344 void *pUserData 1345); 1346 1347/* 1348** CAPI3REF: Authorizer Return Codes {F12590} 1349** 1350** The [sqlite3_set_authorizer | authorizer callback function] must 1351** return either [SQLITE_OK] or one of these two constants in order 1352** to signal SQLite whether or not the action is permitted. See the 1353** [sqlite3_set_authorizer | authorizer documentation] for additional 1354** information. 1355*/ 1356#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 1357#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 1358 1359/* 1360** CAPI3REF: Authorizer Action Codes {F12550} 1361** 1362** The [sqlite3_set_authorizer()] interface registers a callback function 1363** that is invoked to authorizer certain SQL statement actions. {F12551} The 1364** second parameter to the callback is an integer code that specifies 1365** what action is being authorized. These are the integer action codes that 1366** the authorizer callback may be passed. {END} 1367** 1368** These action code values signify what kind of operation is to be 1369** authorized. {F12552} The 3rd and 4th parameters to the authorization 1370** callback function will be parameters or NULL depending on which of these 1371** codes is used as the second parameter. {F12553} The 5th parameter to the 1372** authorizer callback is the name of the database ("main", "temp", 1373** etc.) if applicable. {F12554} The 6th parameter to the authorizer callback 1374** is the name of the inner-most trigger or view that is responsible for 1375** the access attempt or NULL if this access attempt is directly from 1376** top-level SQL code. 1377*/ 1378/******************************************* 3rd ************ 4th ***********/ 1379#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 1380#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 1381#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 1382#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 1383#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 1384#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 1385#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 1386#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 1387#define SQLITE_DELETE 9 /* Table Name NULL */ 1388#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 1389#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 1390#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 1391#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 1392#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 1393#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 1394#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 1395#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 1396#define SQLITE_INSERT 18 /* Table Name NULL */ 1397#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 1398#define SQLITE_READ 20 /* Table Name Column Name */ 1399#define SQLITE_SELECT 21 /* NULL NULL */ 1400#define SQLITE_TRANSACTION 22 /* NULL NULL */ 1401#define SQLITE_UPDATE 23 /* Table Name Column Name */ 1402#define SQLITE_ATTACH 24 /* Filename NULL */ 1403#define SQLITE_DETACH 25 /* Database Name NULL */ 1404#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 1405#define SQLITE_REINDEX 27 /* Index Name NULL */ 1406#define SQLITE_ANALYZE 28 /* Table Name NULL */ 1407#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 1408#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 1409#define SQLITE_FUNCTION 31 /* Function Name NULL */ 1410#define SQLITE_COPY 0 /* No longer used */ 1411 1412/* 1413** CAPI3REF: Tracing And Profiling Functions {F12280} 1414** 1415** These routines register callback functions that can be used for 1416** tracing and profiling the execution of SQL statements. 1417** 1418** {F12281} The callback function registered by sqlite3_trace() is invoked 1419** at the first [sqlite3_step()] for the evaluation of an SQL statement. 1420** {F12282} Only a single trace callback can be registered at a time. 1421** Each call to sqlite3_trace() overrides the previous. {F12283} A 1422** NULL callback for sqlite3_trace() disables tracing. {F12284} The 1423** first argument to the trace callback is a copy of the pointer which 1424** was the 3rd argument to sqlite3_trace. {F12285} The second argument 1425** to the trace callback is a zero-terminated UTF8 string containing 1426** the original text of the SQL statement as it was passed into 1427** [sqlite3_prepare_v2()] or the equivalent. {END} Note that the 1428** host parameter are not expanded in the SQL statement text. 1429** 1430** {F12287} The callback function registered by sqlite3_profile() is invoked 1431** as each SQL statement finishes. {F12288} The first parameter to the 1432** profile callback is a copy of the 3rd parameter to sqlite3_profile(). 1433** {F12289} The second parameter to the profile callback is a 1434** zero-terminated UTF-8 string that contains the complete text of 1435** the SQL statement as it was processed by [sqlite3_prepare_v2()] or 1436** the equivalent. {F12290} The third parameter to the profile 1437** callback is an estimate of the number of nanoseconds of 1438** wall-clock time required to run the SQL statement from start 1439** to finish. {END} 1440** 1441** The sqlite3_profile() API is currently considered experimental and 1442** is subject to change. 1443*/ 1444void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 1445void *sqlite3_profile(sqlite3*, 1446 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 1447 1448/* 1449** CAPI3REF: Query Progress Callbacks {F12910} 1450** 1451** {F12911} This routine configures a callback function - the 1452** progress callback - that is invoked periodically during long 1453** running calls to [sqlite3_exec()], [sqlite3_step()] and 1454** [sqlite3_get_table()]. {END} An example use for this 1455** interface is to keep a GUI updated during a large query. 1456** 1457** {F12912} The progress callback is invoked once for every N virtual 1458** machine opcodes, where N is the second argument to this function. 1459** {F12913} The progress callback itself is identified by the third 1460** argument to this function. {F12914} The fourth argument to this 1461** function is a void pointer passed to the progress callback 1462** function each time it is invoked. {END} 1463** 1464** {F12915} If a call to [sqlite3_exec()], [sqlite3_step()], or 1465** [sqlite3_get_table()] results in fewer than N opcodes being executed, 1466** then the progress callback is never invoked. {END} 1467** 1468** {F12916} Only a single progress callback function may be registered for each 1469** open database connection. Every call to sqlite3_progress_handler() 1470** overwrites the results of the previous call. {F12917} 1471** To remove the progress callback altogether, pass NULL as the third 1472** argument to this function. {END} 1473** 1474** {F12918} If the progress callback returns a result other than 0, then 1475** the current query is immediately terminated and any database changes 1476** rolled back. {F12919} 1477** The containing [sqlite3_exec()], [sqlite3_step()], or 1478** [sqlite3_get_table()] call returns SQLITE_INTERRUPT. {END} This feature 1479** can be used, for example, to implement the "Cancel" button on a 1480** progress dialog box in a GUI. 1481*/ 1482void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 1483 1484/* 1485** CAPI3REF: Opening A New Database Connection {F12700} 1486** 1487** {F12701} These routines open an SQLite database file whose name 1488** is given by the filename argument. 1489** {F12702} The filename argument is interpreted as UTF-8 1490** for [sqlite3_open()] and [sqlite3_open_v2()] and as UTF-16 1491** in the native byte order for [sqlite3_open16()]. 1492** {F12703} An [sqlite3*] handle is returned in *ppDb, even 1493** if an error occurs. {F12723} (Exception: if SQLite is unable 1494** to allocate memory to hold the [sqlite3] object, a NULL will 1495** be written into *ppDb instead of a pointer to the [sqlite3] object.) 1496** {F12704} If the database is opened (and/or created) 1497** successfully, then [SQLITE_OK] is returned. {F12705} Otherwise an 1498** error code is returned. {F12706} The 1499** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 1500** an English language description of the error. 1501** 1502** {F12707} The default encoding for the database will be UTF-8 if 1503** [sqlite3_open()] or [sqlite3_open_v2()] is called and 1504** UTF-16 in the native byte order if [sqlite3_open16()] is used. 1505** 1506** {F12708} Whether or not an error occurs when it is opened, resources 1507** associated with the [sqlite3*] handle should be released by passing it 1508** to [sqlite3_close()] when it is no longer required. 1509** 1510** {F12709} The [sqlite3_open_v2()] interface works like [sqlite3_open()] 1511** except that it acccepts two additional parameters for additional control 1512** over the new database connection. {F12710} The flags parameter can be 1513** one of: 1514** 1515** <ol> 1516** <li> [SQLITE_OPEN_READONLY] 1517** <li> [SQLITE_OPEN_READWRITE] 1518** <li> [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE] 1519** </ol> 1520** 1521** {F12711} The first value opens the database read-only. 1522** {F12712} If the database does not previously exist, an error is returned. 1523** {F12713} The second option opens 1524** the database for reading and writing if possible, or reading only if 1525** if the file is write protected. {F12714} In either case the database 1526** must already exist or an error is returned. {F12715} The third option 1527** opens the database for reading and writing and creates it if it does 1528** not already exist. {F12716} 1529** The third options is behavior that is always used for [sqlite3_open()] 1530** and [sqlite3_open16()]. 1531** 1532** {F12717} If the filename is ":memory:", then an private 1533** in-memory database is created for the connection. {F12718} This in-memory 1534** database will vanish when the database connection is closed. {END} Future 1535** version of SQLite might make use of additional special filenames 1536** that begin with the ":" character. It is recommended that 1537** when a database filename really does begin with 1538** ":" that you prefix the filename with a pathname like "./" to 1539** avoid ambiguity. 1540** 1541** {F12719} If the filename is an empty string, then a private temporary 1542** on-disk database will be created. {F12720} This private database will be 1543** automatically deleted as soon as the database connection is closed. 1544** 1545** {F12721} The fourth parameter to sqlite3_open_v2() is the name of the 1546** [sqlite3_vfs] object that defines the operating system 1547** interface that the new database connection should use. {F12722} If the 1548** fourth parameter is a NULL pointer then the default [sqlite3_vfs] 1549** object is used. {END} 1550** 1551** <b>Note to windows users:</b> The encoding used for the filename argument 1552** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever 1553** codepage is currently defined. Filenames containing international 1554** characters must be converted to UTF-8 prior to passing them into 1555** [sqlite3_open()] or [sqlite3_open_v2()]. 1556*/ 1557int sqlite3_open( 1558 const char *filename, /* Database filename (UTF-8) */ 1559 sqlite3 **ppDb /* OUT: SQLite db handle */ 1560); 1561int sqlite3_open16( 1562 const void *filename, /* Database filename (UTF-16) */ 1563 sqlite3 **ppDb /* OUT: SQLite db handle */ 1564); 1565int sqlite3_open_v2( 1566 const char *filename, /* Database filename (UTF-8) */ 1567 sqlite3 **ppDb, /* OUT: SQLite db handle */ 1568 int flags, /* Flags */ 1569 const char *zVfs /* Name of VFS module to use */ 1570); 1571 1572/* 1573** CAPI3REF: Error Codes And Messages {F12800} 1574** 1575** {F12801} The sqlite3_errcode() interface returns the numeric 1576** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code] 1577** for the most recent failed sqlite3_* API call associated 1578** with [sqlite3] handle 'db'. {U12802} If a prior API call failed but the 1579** most recent API call succeeded, the return value from sqlite3_errcode() 1580** is undefined. {END} 1581** 1582** {F12803} The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 1583** text that describes the error, as either UTF8 or UTF16 respectively. 1584** {F12804} Memory to hold the error message string is managed internally. 1585** {U12805} The 1586** string may be overwritten or deallocated by subsequent calls to SQLite 1587** interface functions. {END} 1588** 1589** {F12806} Calls to many sqlite3_* functions set the error code and 1590** string returned by [sqlite3_errcode()], [sqlite3_errmsg()], and 1591** [sqlite3_errmsg16()] overwriting the previous values. {F12807} 1592** Except, calls to [sqlite3_errcode()], 1593** [sqlite3_errmsg()], and [sqlite3_errmsg16()] themselves do not affect the 1594** results of future invocations. {F12808} Calls to API routines that 1595** do not return an error code (example: [sqlite3_data_count()]) do not 1596** change the error code returned by this routine. {F12809} Interfaces that 1597** are not associated with a specific database connection (examples: 1598** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] do not change 1599** the return code. {END} 1600** 1601** {F12810} Assuming no other intervening sqlite3_* API calls are made, 1602** the error code returned by this function is associated with the same 1603** error as the strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()]. 1604*/ 1605int sqlite3_errcode(sqlite3 *db); 1606const char *sqlite3_errmsg(sqlite3*); 1607const void *sqlite3_errmsg16(sqlite3*); 1608 1609/* 1610** CAPI3REF: SQL Statement Object {F13000} 1611** 1612** An instance of this object represent single SQL statements. This 1613** object is variously known as a "prepared statement" or a 1614** "compiled SQL statement" or simply as a "statement". 1615** 1616** The life of a statement object goes something like this: 1617** 1618** <ol> 1619** <li> Create the object using [sqlite3_prepare_v2()] or a related 1620** function. 1621** <li> Bind values to host parameters using 1622** [sqlite3_bind_blob | sqlite3_bind_* interfaces]. 1623** <li> Run the SQL by calling [sqlite3_step()] one or more times. 1624** <li> Reset the statement using [sqlite3_reset()] then go back 1625** to step 2. Do this zero or more times. 1626** <li> Destroy the object using [sqlite3_finalize()]. 1627** </ol> 1628** 1629** Refer to documentation on individual methods above for additional 1630** information. 1631*/ 1632typedef struct sqlite3_stmt sqlite3_stmt; 1633 1634/* 1635** CAPI3REF: Compiling An SQL Statement {F13010} 1636** 1637** To execute an SQL query, it must first be compiled into a byte-code 1638** program using one of these routines. 1639** 1640** {F13011} The first argument "db" is an [sqlite3 | SQLite database handle] 1641** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()] 1642** or [sqlite3_open16()]. {F13012} 1643** The second argument "zSql" is the statement to be compiled, encoded 1644** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 1645** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2() 1646** use UTF-16. {END} 1647** 1648** {F13013} If the nByte argument is less 1649** than zero, then zSql is read up to the first zero terminator. 1650** {F13014} If nByte is non-negative, then it is the maximum number of 1651** bytes read from zSql. When nByte is non-negative, the 1652** zSql string ends at either the first '\000' or '\u0000' character or 1653** until the nByte-th byte, whichever comes first. {END} 1654** 1655** {F13015} *pzTail is made to point to the first byte past the end of the 1656** first SQL statement in zSql. These routines only compiles the first 1657** statement in zSql, so *pzTail is left pointing to what remains 1658** uncompiled. {END} 1659** 1660** {F13016} *ppStmt is left pointing to a compiled 1661** [sqlite3_stmt | SQL statement structure] that can be 1662** executed using [sqlite3_step()]. Or if there is an error, *ppStmt may be 1663** set to NULL. {F13017} If the input text contains no SQL (if the input 1664** is and empty string or a comment) then *ppStmt is set to NULL. 1665** {U13018} The calling procedure is responsible for deleting the 1666** compiled SQL statement 1667** using [sqlite3_finalize()] after it has finished with it. 1668** 1669** {F13019} On success, [SQLITE_OK] is returned. Otherwise an 1670** [SQLITE_ERROR | error code] is returned. {END} 1671** 1672** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 1673** recommended for all new programs. The two older interfaces are retained 1674** for backwards compatibility, but their use is discouraged. 1675** {F13020} In the "v2" interfaces, the prepared statement 1676** that is returned (the [sqlite3_stmt] object) contains a copy of the 1677** original SQL text. {END} This causes the [sqlite3_step()] interface to 1678** behave a differently in two ways: 1679** 1680** <ol> 1681** <li>{F13022} 1682** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 1683** always used to do, [sqlite3_step()] will automatically recompile the SQL 1684** statement and try to run it again. {F12023} If the schema has changed in 1685** a way that makes the statement no longer valid, [sqlite3_step()] will still 1686** return [SQLITE_SCHEMA]. {END} But unlike the legacy behavior, 1687** [SQLITE_SCHEMA] is now a fatal error. {F12024} Calling 1688** [sqlite3_prepare_v2()] again will not make the 1689** error go away. {F12025} Note: use [sqlite3_errmsg()] to find the text 1690** of the parsing error that results in an [SQLITE_SCHEMA] return. {END} 1691** </li> 1692** 1693** <li> 1694** {F13030} When an error occurs, 1695** [sqlite3_step()] will return one of the detailed 1696** [SQLITE_ERROR | result codes] or 1697** [SQLITE_IOERR_READ | extended result codes]. {F13031} 1698** The legacy behavior was that [sqlite3_step()] would only return a generic 1699** [SQLITE_ERROR] result code and you would have to make a second call to 1700** [sqlite3_reset()] in order to find the underlying cause of the problem. 1701** {F13032} 1702** With the "v2" prepare interfaces, the underlying reason for the error is 1703** returned immediately. {END} 1704** </li> 1705** </ol> 1706*/ 1707int sqlite3_prepare( 1708 sqlite3 *db, /* Database handle */ 1709 const char *zSql, /* SQL statement, UTF-8 encoded */ 1710 int nByte, /* Maximum length of zSql in bytes. */ 1711 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 1712 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 1713); 1714int sqlite3_prepare_v2( 1715 sqlite3 *db, /* Database handle */ 1716 const char *zSql, /* SQL statement, UTF-8 encoded */ 1717 int nByte, /* Maximum length of zSql in bytes. */ 1718 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 1719 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 1720); 1721int sqlite3_prepare16( 1722 sqlite3 *db, /* Database handle */ 1723 const void *zSql, /* SQL statement, UTF-16 encoded */ 1724 int nByte, /* Maximum length of zSql in bytes. */ 1725 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 1726 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 1727); 1728int sqlite3_prepare16_v2( 1729 sqlite3 *db, /* Database handle */ 1730 const void *zSql, /* SQL statement, UTF-16 encoded */ 1731 int nByte, /* Maximum length of zSql in bytes. */ 1732 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 1733 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 1734); 1735 1736/* 1737** CAPIREF: Retrieving Statement SQL {F13100} 1738** 1739** {F13101} If the compiled SQL statement passed as an argument was 1740** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()], 1741** then this function returns a pointer to a zero-terminated string 1742** containing a copy of the original SQL statement. {F13102} The 1743** pointer is valid until the statement 1744** is deleted using sqlite3_finalize(). 1745** {F13103} The string returned by sqlite3_sql() is always UTF8 even 1746** if a UTF16 string was originally entered using [sqlite3_prepare16_v2()] 1747** or the equivalent. 1748** 1749** {F13104} If the statement was compiled using either of the legacy 1750** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this 1751** function returns NULL. 1752*/ 1753const char *sqlite3_sql(sqlite3_stmt *pStmt); 1754 1755/* 1756** CAPI3REF: Dynamically Typed Value Object {F15000} 1757** 1758** {F15001} SQLite uses the sqlite3_value object to represent all values 1759** that are or can be stored in a database table. {END} 1760** SQLite uses dynamic typing for the values it stores. 1761** {F15002} Values stored in sqlite3_value objects can be 1762** be integers, floating point values, strings, BLOBs, or NULL. 1763*/ 1764typedef struct Mem sqlite3_value; 1765 1766/* 1767** CAPI3REF: SQL Function Context Object {F16001} 1768** 1769** The context in which an SQL function executes is stored in an 1770** sqlite3_context object. {F16002} A pointer to an sqlite3_context 1771** object is always first parameter to application-defined SQL functions. 1772*/ 1773typedef struct sqlite3_context sqlite3_context; 1774 1775/* 1776** CAPI3REF: Binding Values To Prepared Statements {F13500} 1777** 1778** {F13501} In the SQL strings input to [sqlite3_prepare_v2()] and its 1779** variants, literals may be replace by a parameter in one 1780** of these forms: 1781** 1782** <ul> 1783** <li> ? 1784** <li> ?NNN 1785** <li> :AAA 1786** <li> @AAA 1787** <li> $VVV 1788** </ul> 1789** 1790** In the parameter forms shown above NNN is an integer literal, 1791** AAA is an alphanumeric identifier and VVV is a variable name according 1792** to the syntax rules of the TCL programming language. {END} 1793** The values of these parameters (also called "host parameter names") 1794** can be set using the sqlite3_bind_*() routines defined here. 1795** 1796** {F13502} The first argument to the sqlite3_bind_*() routines always 1797** is a pointer to the [sqlite3_stmt] object returned from 1798** [sqlite3_prepare_v2()] or its variants. {F13503} The second 1799** argument is the index of the parameter to be set. {F13504} The 1800** first parameter has an index of 1. {F13505} When the same named 1801** parameter is used more than once, second and subsequent 1802** occurrences have the same index as the first occurrence. 1803** {F13506} The index for named parameters can be looked up using the 1804** [sqlite3_bind_parameter_name()] API if desired. {F13507} The index 1805** for "?NNN" parameters is the value of NNN. 1806** {F13508} The NNN value must be between 1 and the compile-time 1807** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999). {END} 1808** See <a href="limits.html">limits.html</a> for additional information. 1809** 1810** {F13509} The third argument is the value to bind to the parameter. {END} 1811** 1812** {F13510} In those 1813** routines that have a fourth argument, its value is the number of bytes 1814** in the parameter. To be clear: the value is the number of bytes in the 1815** string, not the number of characters. {F13511} The number 1816** of bytes does not include the zero-terminator at the end of strings. 1817** {F13512} 1818** If the fourth parameter is negative, the length of the string is 1819** number of bytes up to the first zero terminator. {END} 1820** 1821** {F13513} 1822** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 1823** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 1824** text after SQLite has finished with it. {F13514} If the fifth argument is 1825** the special value [SQLITE_STATIC], then the library assumes that the 1826** information is in static, unmanaged space and does not need to be freed. 1827** {F13515} If the fifth argument has the value [SQLITE_TRANSIENT], then 1828** SQLite makes its own private copy of the data immediately, before 1829** the sqlite3_bind_*() routine returns. {END} 1830** 1831** {F13520} The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 1832** is filled with zeros. {F13521} A zeroblob uses a fixed amount of memory 1833** (just an integer to hold it size) while it is being processed. {END} 1834** Zeroblobs are intended to serve as place-holders for BLOBs whose 1835** content is later written using 1836** [sqlite3_blob_open | increment BLOB I/O] routines. {F13522} A negative 1837** value for the zeroblob results in a zero-length BLOB. {END} 1838** 1839** {F13530} The sqlite3_bind_*() routines must be called after 1840** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and 1841** before [sqlite3_step()]. {F13531} 1842** Bindings are not cleared by the [sqlite3_reset()] routine. 1843** {F13532} Unbound parameters are interpreted as NULL. {END} 1844** 1845** {F13540} These routines return [SQLITE_OK] on success or an error code if 1846** anything goes wrong. {F13541} [SQLITE_RANGE] is returned if the parameter 1847** index is out of range. {F13542} [SQLITE_NOMEM] is returned if malloc fails. 1848** {F13543} [SQLITE_MISUSE] is returned if these routines are called on a 1849** virtual machine that is the wrong state or which has already been finalized. 1850*/ 1851int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 1852int sqlite3_bind_double(sqlite3_stmt*, int, double); 1853int sqlite3_bind_int(sqlite3_stmt*, int, int); 1854int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 1855int sqlite3_bind_null(sqlite3_stmt*, int); 1856int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 1857int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 1858int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 1859int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 1860 1861/* 1862** CAPI3REF: Number Of Host Parameters {F13600} 1863** 1864** {F13601} Return the largest host parameter index in the precompiled 1865** statement given as the argument. {F13602} When the host parameters 1866** are of the forms like ":AAA", "$VVV", "@AAA", or "?", 1867** then they are assigned sequential increasing numbers beginning 1868** with one, so the value returned is the number of parameters. 1869** {F13603} However 1870** if the same host parameter name is used multiple times, each occurrance 1871** is given the same number, so the value returned in that case is the number 1872** of unique host parameter names. {F13604} If host parameters of the 1873** form "?NNN" are used (where NNN is an integer) then there might be 1874** gaps in the numbering and the value returned by this interface is 1875** the index of the host parameter with the largest index value. {END} 1876** 1877** {U13605} The prepared statement must not be [sqlite3_finalize | finalized] 1878** prior to this routine returning. Otherwise the results are undefined 1879** and probably undesirable. 1880*/ 1881int sqlite3_bind_parameter_count(sqlite3_stmt*); 1882 1883/* 1884** CAPI3REF: Name Of A Host Parameter {F13620} 1885** 1886** {F13621} This routine returns a pointer to the name of the n-th 1887** parameter in a [sqlite3_stmt | prepared statement]. {F13622} 1888** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name 1889** which is the string ":AAA" or "@AAA" or "$VVV". 1890** In other words, the initial ":" or "$" or "@" 1891** is included as part of the name. {F13626} 1892** Parameters of the form "?" or "?NNN" have no name. 1893** 1894** {F13623} The first host parameter has an index of 1, not 0. 1895** 1896** {F13624} If the value n is out of range or if the n-th parameter is 1897** nameless, then NULL is returned. {F13625} The returned string is 1898** always in the UTF-8 encoding even if the named parameter was 1899** originally specified as UTF-16 in [sqlite3_prepare16()] or 1900** [sqlite3_prepare16_v2()]. 1901*/ 1902const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 1903 1904/* 1905** CAPI3REF: Index Of A Parameter With A Given Name {F13640} 1906** 1907** {F13641} This routine returns the index of a host parameter with the 1908** given name. {F13642} The name must match exactly. {F13643} 1909** If no parameter with the given name is found, return 0. 1910** {F13644} Parameter names must be UTF8. 1911*/ 1912int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 1913 1914/* 1915** CAPI3REF: Reset All Bindings On A Prepared Statement {F13660} 1916** 1917** {F13661} Contrary to the intuition of many, [sqlite3_reset()] does not 1918** reset the [sqlite3_bind_blob | bindings] on a 1919** [sqlite3_stmt | prepared statement]. {F13662} Use this routine to 1920** reset all host parameters to NULL. 1921*/ 1922int sqlite3_clear_bindings(sqlite3_stmt*); 1923 1924/* 1925** CAPI3REF: Number Of Columns In A Result Set {F13710} 1926** 1927** {F13711} Return the number of columns in the result set returned by the 1928** [sqlite3_stmt | compiled SQL statement]. {F13712} This routine returns 0 1929** if pStmt is an SQL statement that does not return data (for 1930** example an UPDATE). 1931*/ 1932int sqlite3_column_count(sqlite3_stmt *pStmt); 1933 1934/* 1935** CAPI3REF: Column Names In A Result Set {F13720} 1936** 1937** {F13721} These routines return the name assigned to a particular column 1938** in the result set of a SELECT statement. {F13722} The sqlite3_column_name() 1939** interface returns a pointer to a zero-terminated UTF8 string 1940** and sqlite3_column_name16() returns a pointer to a zero-terminated 1941** UTF16 string. {F13723} The first parameter is the 1942** [sqlite3_stmt | prepared statement] that implements the SELECT statement. 1943** The second parameter is the column number. The left-most column is 1944** number 0. 1945** 1946** {F13724} The returned string pointer is valid until either the 1947** [sqlite3_stmt | prepared statement] is destroyed by [sqlite3_finalize()] 1948** or until the next call sqlite3_column_name() or sqlite3_column_name16() 1949** on the same column. 1950** 1951** {F13725} If sqlite3_malloc() fails during the processing of either routine 1952** (for example during a conversion from UTF-8 to UTF-16) then a 1953** NULL pointer is returned. 1954*/ 1955const char *sqlite3_column_name(sqlite3_stmt*, int N); 1956const void *sqlite3_column_name16(sqlite3_stmt*, int N); 1957 1958/* 1959** CAPI3REF: Source Of Data In A Query Result {F13740} 1960** 1961** {F13741} These routines provide a means to determine what column of what 1962** table in which database a result of a SELECT statement comes from. 1963** {F13742} The name of the database or table or column can be returned as 1964** either a UTF8 or UTF16 string. {F13743} The _database_ routines return 1965** the database name, the _table_ routines return the table name, and 1966** the origin_ routines return the column name. {F13744} 1967** The returned string is valid until 1968** the [sqlite3_stmt | prepared statement] is destroyed using 1969** [sqlite3_finalize()] or until the same information is requested 1970** again in a different encoding. 1971** 1972** {F13745} The names returned are the original un-aliased names of the 1973** database, table, and column. 1974** 1975** {F13746} The first argument to the following calls is a 1976** [sqlite3_stmt | compiled SQL statement]. 1977** {F13747} These functions return information about the Nth column returned by 1978** the statement, where N is the second function argument. 1979** 1980** {F13748} If the Nth column returned by the statement is an expression 1981** or subquery and is not a column value, then all of these functions 1982** return NULL. {F13749} Otherwise, they return the 1983** name of the attached database, table and column that query result 1984** column was extracted from. 1985** 1986** {F13750} As with all other SQLite APIs, those postfixed with "16" return 1987** UTF-16 encoded strings, the other functions return UTF-8. {END} 1988** 1989** These APIs are only available if the library was compiled with the 1990** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 1991** 1992** {U13751} 1993** If two or more threads call one or more of these routines against the same 1994** prepared statement and column at the same time then the results are 1995** undefined. 1996*/ 1997const char *sqlite3_column_database_name(sqlite3_stmt*,int); 1998const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 1999const char *sqlite3_column_table_name(sqlite3_stmt*,int); 2000const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 2001const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 2002const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 2003 2004/* 2005** CAPI3REF: Declared Datatype Of A Query Result {F13760} 2006** 2007** The first parameter is a [sqlite3_stmt | compiled SQL statement]. 2008** {F13761} If this statement is a SELECT statement and the Nth column of the 2009** returned result set of that SELECT is a table column (not an 2010** expression or subquery) then the declared type of the table 2011** column is returned. {F13762} If the Nth column of the result set is an 2012** expression or subquery, then a NULL pointer is returned. 2013** {F13763} The returned string is always UTF-8 encoded. {END} 2014** For example, in the database schema: 2015** 2016** CREATE TABLE t1(c1 VARIANT); 2017** 2018** And the following statement compiled: 2019** 2020** SELECT c1 + 1, c1 FROM t1; 2021** 2022** Then this routine would return the string "VARIANT" for the second 2023** result column (i==1), and a NULL pointer for the first result column 2024** (i==0). 2025** 2026** SQLite uses dynamic run-time typing. So just because a column 2027** is declared to contain a particular type does not mean that the 2028** data stored in that column is of the declared type. SQLite is 2029** strongly typed, but the typing is dynamic not static. Type 2030** is associated with individual values, not with the containers 2031** used to hold those values. 2032*/ 2033const char *sqlite3_column_decltype(sqlite3_stmt *, int i); 2034const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 2035 2036/* 2037** CAPI3REF: Evaluate An SQL Statement {F13200} 2038** 2039** After an [sqlite3_stmt | SQL statement] has been prepared with a call 2040** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of 2041** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], 2042** then this function must be called one or more times to evaluate the 2043** statement. 2044** 2045** The details of the behavior of this sqlite3_step() interface depend 2046** on whether the statement was prepared using the newer "v2" interface 2047** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 2048** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 2049** new "v2" interface is recommended for new applications but the legacy 2050** interface will continue to be supported. 2051** 2052** In the lagacy interface, the return value will be either [SQLITE_BUSY], 2053** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 2054** With the "v2" interface, any of the other [SQLITE_OK | result code] 2055** or [SQLITE_IOERR_READ | extended result code] might be returned as 2056** well. 2057** 2058** [SQLITE_BUSY] means that the database engine was unable to acquire the 2059** database locks it needs to do its job. If the statement is a COMMIT 2060** or occurs outside of an explicit transaction, then you can retry the 2061** statement. If the statement is not a COMMIT and occurs within a 2062** explicit transaction then you should rollback the transaction before 2063** continuing. 2064** 2065** [SQLITE_DONE] means that the statement has finished executing 2066** successfully. sqlite3_step() should not be called again on this virtual 2067** machine without first calling [sqlite3_reset()] to reset the virtual 2068** machine back to its initial state. 2069** 2070** If the SQL statement being executed returns any data, then 2071** [SQLITE_ROW] is returned each time a new row of data is ready 2072** for processing by the caller. The values may be accessed using 2073** the [sqlite3_column_int | column access functions]. 2074** sqlite3_step() is called again to retrieve the next row of data. 2075** 2076** [SQLITE_ERROR] means that a run-time error (such as a constraint 2077** violation) has occurred. sqlite3_step() should not be called again on 2078** the VM. More information may be found by calling [sqlite3_errmsg()]. 2079** With the legacy interface, a more specific error code (example: 2080** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 2081** can be obtained by calling [sqlite3_reset()] on the 2082** [sqlite3_stmt | prepared statement]. In the "v2" interface, 2083** the more specific error code is returned directly by sqlite3_step(). 2084** 2085** [SQLITE_MISUSE] means that the this routine was called inappropriately. 2086** Perhaps it was called on a [sqlite3_stmt | prepared statement] that has 2087** already been [sqlite3_finalize | finalized] or on one that had 2088** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 2089** be the case that the same database connection is being used by two or 2090** more threads at the same moment in time. 2091** 2092** <b>Goofy Interface Alert:</b> 2093** In the legacy interface, 2094** the sqlite3_step() API always returns a generic error code, 2095** [SQLITE_ERROR], following any error other than [SQLITE_BUSY] 2096** and [SQLITE_MISUSE]. You must call [sqlite3_reset()] or 2097** [sqlite3_finalize()] in order to find one of the specific 2098** [SQLITE_ERROR | result codes] that better describes the error. 2099** We admit that this is a goofy design. The problem has been fixed 2100** with the "v2" interface. If you prepare all of your SQL statements 2101** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 2102** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the 2103** more specific [SQLITE_ERROR | result codes] are returned directly 2104** by sqlite3_step(). The use of the "v2" interface is recommended. 2105*/ 2106int sqlite3_step(sqlite3_stmt*); 2107 2108/* 2109** CAPI3REF: Number of columns in a result set {F13770} 2110** 2111** Return the number of values in the current row of the result set. 2112** 2113** {F13771} After a call to [sqlite3_step()] that returns [SQLITE_ROW], 2114** this routine 2115** will return the same value as the [sqlite3_column_count()] function. 2116** {F13772} 2117** After [sqlite3_step()] has returned an [SQLITE_DONE], [SQLITE_BUSY], or 2118** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been 2119** called on the [sqlite3_stmt | prepared statement] for the first time, 2120** this routine returns zero. 2121*/ 2122int sqlite3_data_count(sqlite3_stmt *pStmt); 2123 2124/* 2125** CAPI3REF: Fundamental Datatypes {F10265} 2126** 2127** {F10266}Every value in SQLite has one of five fundamental datatypes: 2128** 2129** <ul> 2130** <li> 64-bit signed integer 2131** <li> 64-bit IEEE floating point number 2132** <li> string 2133** <li> BLOB 2134** <li> NULL 2135** </ul> {END} 2136** 2137** These constants are codes for each of those types. 2138** 2139** Note that the SQLITE_TEXT constant was also used in SQLite version 2 2140** for a completely different meaning. Software that links against both 2141** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not 2142** SQLITE_TEXT. 2143*/ 2144#define SQLITE_INTEGER 1 2145#define SQLITE_FLOAT 2 2146#define SQLITE_BLOB 4 2147#define SQLITE_NULL 5 2148#ifdef SQLITE_TEXT 2149# undef SQLITE_TEXT 2150#else 2151# define SQLITE_TEXT 3 2152#endif 2153#define SQLITE3_TEXT 3 2154 2155/* 2156** CAPI3REF: Results Values From A Query {F13800} 2157** 2158** These routines return information about 2159** a single column of the current result row of a query. In every 2160** case the first argument is a pointer to the 2161** [sqlite3_stmt | SQL statement] that is being 2162** evaluated (the [sqlite3_stmt*] that was returned from 2163** [sqlite3_prepare_v2()] or one of its variants) and 2164** the second argument is the index of the column for which information 2165** should be returned. The left-most column of the result set 2166** has an index of 0. 2167** 2168** If the SQL statement is not currently point to a valid row, or if the 2169** the column index is out of range, the result is undefined. 2170** These routines may only be called when the most recent call to 2171** [sqlite3_step()] has returned [SQLITE_ROW] and neither 2172** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently. 2173** If any of these routines are called after [sqlite3_reset()] or 2174** [sqlite3_finalize()] or after [sqlite3_step()] has returned 2175** something other than [SQLITE_ROW], the results are undefined. 2176** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 2177** are called from a different thread while any of these routines 2178** are pending, then the results are undefined. 2179** 2180** The sqlite3_column_type() routine returns 2181** [SQLITE_INTEGER | datatype code] for the initial data type 2182** of the result column. The returned value is one of [SQLITE_INTEGER], 2183** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 2184** returned by sqlite3_column_type() is only meaningful if no type 2185** conversions have occurred as described below. After a type conversion, 2186** the value returned by sqlite3_column_type() is undefined. Future 2187** versions of SQLite may change the behavior of sqlite3_column_type() 2188** following a type conversion. 2189** 2190** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 2191** routine returns the number of bytes in that BLOB or string. 2192** If the result is a UTF-16 string, then sqlite3_column_bytes() converts 2193** the string to UTF-8 and then returns the number of bytes. 2194** If the result is a numeric value then sqlite3_column_bytes() uses 2195** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 2196** the number of bytes in that string. 2197** The value returned does not include the zero terminator at the end 2198** of the string. For clarity: the value returned is the number of 2199** bytes in the string, not the number of characters. 2200** 2201** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 2202** even zero-length strings, are always zero terminated. The return 2203** value from sqlite3_column_blob() for a zero-length blob is an arbitrary 2204** pointer, possibly even a NULL pointer. 2205** 2206** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() 2207** but leaves the result in UTF-16 instead of UTF-8. 2208** The zero terminator is not included in this count. 2209** 2210** These routines attempt to convert the value where appropriate. For 2211** example, if the internal representation is FLOAT and a text result 2212** is requested, [sqlite3_snprintf()] is used internally to do the conversion 2213** automatically. The following table details the conversions that 2214** are applied: 2215** 2216** <blockquote> 2217** <table border="1"> 2218** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 2219** 2220** <tr><td> NULL <td> INTEGER <td> Result is 0 2221** <tr><td> NULL <td> FLOAT <td> Result is 0.0 2222** <tr><td> NULL <td> TEXT <td> Result is NULL pointer 2223** <tr><td> NULL <td> BLOB <td> Result is NULL pointer 2224** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 2225** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 2226** <tr><td> INTEGER <td> BLOB <td> Same as for INTEGER->TEXT 2227** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer 2228** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 2229** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT 2230** <tr><td> TEXT <td> INTEGER <td> Use atoi() 2231** <tr><td> TEXT <td> FLOAT <td> Use atof() 2232** <tr><td> TEXT <td> BLOB <td> No change 2233** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() 2234** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() 2235** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 2236** </table> 2237** </blockquote> 2238** 2239** The table above makes reference to standard C library functions atoi() 2240** and atof(). SQLite does not really use these functions. It has its 2241** on equavalent internal routines. The atoi() and atof() names are 2242** used in the table for brevity and because they are familiar to most 2243** C programmers. 2244** 2245** Note that when type conversions occur, pointers returned by prior 2246** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 2247** sqlite3_column_text16() may be invalidated. 2248** Type conversions and pointer invalidations might occur 2249** in the following cases: 2250** 2251** <ul> 2252** <li><p> The initial content is a BLOB and sqlite3_column_text() 2253** or sqlite3_column_text16() is called. A zero-terminator might 2254** need to be added to the string.</p></li> 2255** 2256** <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or 2257** sqlite3_column_text16() is called. The content must be converted 2258** to UTF-16.</p></li> 2259** 2260** <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or 2261** sqlite3_column_text() is called. The content must be converted 2262** to UTF-8.</p></li> 2263** </ul> 2264** 2265** Conversions between UTF-16be and UTF-16le are always done in place and do 2266** not invalidate a prior pointer, though of course the content of the buffer 2267** that the prior pointer points to will have been modified. Other kinds 2268** of conversion are done in place when it is possible, but sometime it is 2269** not possible and in those cases prior pointers are invalidated. 2270** 2271** The safest and easiest to remember policy is to invoke these routines 2272** in one of the following ways: 2273** 2274** <ul> 2275** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 2276** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 2277** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 2278** </ul> 2279** 2280** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(), 2281** or sqlite3_column_text16() first to force the result into the desired 2282** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to 2283** find the size of the result. Do not mix call to sqlite3_column_text() or 2284** sqlite3_column_blob() with calls to sqlite3_column_bytes16(). And do not 2285** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes(). 2286** 2287** The pointers returned are valid until a type conversion occurs as 2288** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 2289** [sqlite3_finalize()] is called. The memory space used to hold strings 2290** and blobs is freed automatically. Do <b>not</b> pass the pointers returned 2291** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 2292** [sqlite3_free()]. 2293** 2294** If a memory allocation error occurs during the evaluation of any 2295** of these routines, a default value is returned. The default value 2296** is either the integer 0, the floating point number 0.0, or a NULL 2297** pointer. Subsequent calls to [sqlite3_errcode()] will return 2298** [SQLITE_NOMEM]. 2299*/ 2300const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 2301int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 2302int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 2303double sqlite3_column_double(sqlite3_stmt*, int iCol); 2304int sqlite3_column_int(sqlite3_stmt*, int iCol); 2305sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 2306const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 2307const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 2308int sqlite3_column_type(sqlite3_stmt*, int iCol); 2309sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 2310 2311/* 2312** CAPI3REF: Destroy A Prepared Statement Object {F13300} 2313** 2314** The sqlite3_finalize() function is called to delete a 2315** [sqlite3_stmt | compiled SQL statement]. If the statement was 2316** executed successfully, or not executed at all, then SQLITE_OK is returned. 2317** If execution of the statement failed then an 2318** [SQLITE_ERROR | error code] or [SQLITE_IOERR_READ | extended error code] 2319** is returned. 2320** 2321** This routine can be called at any point during the execution of the 2322** [sqlite3_stmt | virtual machine]. If the virtual machine has not 2323** completed execution when this routine is called, that is like 2324** encountering an error or an interrupt. (See [sqlite3_interrupt()].) 2325** Incomplete updates may be rolled back and transactions cancelled, 2326** depending on the circumstances, and the 2327** [SQLITE_ERROR | result code] returned will be [SQLITE_ABORT]. 2328*/ 2329int sqlite3_finalize(sqlite3_stmt *pStmt); 2330 2331/* 2332** CAPI3REF: Reset A Prepared Statement Object {F13330} 2333** 2334** The sqlite3_reset() function is called to reset a 2335** [sqlite3_stmt | compiled SQL statement] object. 2336** back to its initial state, ready to be re-executed. 2337** Any SQL statement variables that had values bound to them using 2338** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 2339** Use [sqlite3_clear_bindings()] to reset the bindings. 2340*/ 2341int sqlite3_reset(sqlite3_stmt *pStmt); 2342 2343/* 2344** CAPI3REF: Create Or Redefine SQL Functions {F16100} 2345** 2346** The following two functions are used to add SQL functions or aggregates 2347** or to redefine the behavior of existing SQL functions or aggregates. The 2348** difference only between the two is that the second parameter, the 2349** name of the (scalar) function or aggregate, is encoded in UTF-8 for 2350** sqlite3_create_function() and UTF-16 for sqlite3_create_function16(). 2351** 2352** The first argument is the [sqlite3 | database handle] that holds the 2353** SQL function or aggregate is to be added or redefined. If a single 2354** program uses more than one database handle internally, then SQL 2355** functions or aggregates must be added individually to each database 2356** handle with which they will be used. 2357** 2358** The second parameter is the name of the SQL function to be created 2359** or redefined. 2360** The length of the name is limited to 255 bytes, exclusive of the 2361** zero-terminator. Note that the name length limit is in bytes, not 2362** characters. Any attempt to create a function with a longer name 2363** will result in an SQLITE_ERROR error. 2364** 2365** The third parameter is the number of arguments that the SQL function or 2366** aggregate takes. If this parameter is negative, then the SQL function or 2367** aggregate may take any number of arguments. 2368** 2369** The fourth parameter, eTextRep, specifies what 2370** [SQLITE_UTF8 | text encoding] this SQL function prefers for 2371** its parameters. Any SQL function implementation should be able to work 2372** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be 2373** more efficient with one encoding than another. It is allowed to 2374** invoke sqlite3_create_function() or sqlite3_create_function16() multiple 2375** times with the same function but with different values of eTextRep. 2376** When multiple implementations of the same function are available, SQLite 2377** will pick the one that involves the least amount of data conversion. 2378** If there is only a single implementation which does not care what 2379** text encoding is used, then the fourth argument should be 2380** [SQLITE_ANY]. 2381** 2382** The fifth parameter is an arbitrary pointer. The implementation 2383** of the function can gain access to this pointer using 2384** [sqlite3_user_data()]. 2385** 2386** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are 2387** pointers to C-language functions that implement the SQL 2388** function or aggregate. A scalar SQL function requires an implementation of 2389** the xFunc callback only, NULL pointers should be passed as the xStep 2390** and xFinal parameters. An aggregate SQL function requires an implementation 2391** of xStep and xFinal and NULL should be passed for xFunc. To delete an 2392** existing SQL function or aggregate, pass NULL for all three function 2393** callback. 2394** 2395** It is permitted to register multiple implementations of the same 2396** functions with the same name but with either differing numbers of 2397** arguments or differing perferred text encodings. SQLite will use 2398** the implementation most closely matches the way in which the 2399** SQL function is used. 2400*/ 2401int sqlite3_create_function( 2402 sqlite3 *, 2403 const char *zFunctionName, 2404 int nArg, 2405 int eTextRep, 2406 void*, 2407 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 2408 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 2409 void (*xFinal)(sqlite3_context*) 2410); 2411int sqlite3_create_function16( 2412 sqlite3*, 2413 const void *zFunctionName, 2414 int nArg, 2415 int eTextRep, 2416 void*, 2417 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 2418 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 2419 void (*xFinal)(sqlite3_context*) 2420); 2421 2422/* 2423** CAPI3REF: Text Encodings {F10267} 2424** 2425** These constant define integer codes that represent the various 2426** text encodings supported by SQLite. 2427*/ 2428#define SQLITE_UTF8 1 2429#define SQLITE_UTF16LE 2 2430#define SQLITE_UTF16BE 3 2431#define SQLITE_UTF16 4 /* Use native byte order */ 2432#define SQLITE_ANY 5 /* sqlite3_create_function only */ 2433#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 2434 2435/* 2436** CAPI3REF: Obsolete Functions 2437** 2438** These functions are all now obsolete. In order to maintain 2439** backwards compatibility with older code, we continue to support 2440** these functions. However, new development projects should avoid 2441** the use of these functions. To help encourage people to avoid 2442** using these functions, we are not going to tell you want they do. 2443*/ 2444int sqlite3_aggregate_count(sqlite3_context*); 2445int sqlite3_expired(sqlite3_stmt*); 2446int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 2447int sqlite3_global_recover(void); 2448void sqlite3_thread_cleanup(void); 2449int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); 2450 2451/* 2452** CAPI3REF: Obtaining SQL Function Parameter Values {F15100} 2453** 2454** The C-language implementation of SQL functions and aggregates uses 2455** this set of interface routines to access the parameter values on 2456** the function or aggregate. 2457** 2458** The xFunc (for scalar functions) or xStep (for aggregates) parameters 2459** to [sqlite3_create_function()] and [sqlite3_create_function16()] 2460** define callbacks that implement the SQL functions and aggregates. 2461** The 4th parameter to these callbacks is an array of pointers to 2462** [sqlite3_value] objects. There is one [sqlite3_value] object for 2463** each parameter to the SQL function. These routines are used to 2464** extract values from the [sqlite3_value] objects. 2465** 2466** These routines work just like the corresponding 2467** [sqlite3_column_blob | sqlite3_column_* routines] except that 2468** these routines take a single [sqlite3_value*] pointer instead 2469** of an [sqlite3_stmt*] pointer and an integer column number. 2470** 2471** The sqlite3_value_text16() interface extracts a UTF16 string 2472** in the native byte-order of the host machine. The 2473** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 2474** extract UTF16 strings as big-endian and little-endian respectively. 2475** 2476** The sqlite3_value_numeric_type() interface attempts to apply 2477** numeric affinity to the value. This means that an attempt is 2478** made to convert the value to an integer or floating point. If 2479** such a conversion is possible without loss of information (in other 2480** words if the value is a string that looks like a number) 2481** then the conversion is done. Otherwise no conversion occurs. The 2482** [SQLITE_INTEGER | datatype] after conversion is returned. 2483** 2484** Please pay particular attention to the fact that the pointer that 2485** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or 2486** [sqlite3_value_text16()] can be invalidated by a subsequent call to 2487** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 2488** or [sqlite3_value_text16()]. 2489** 2490** These routines must be called from the same thread as 2491** the SQL function that supplied the sqlite3_value* parameters. 2492** Or, if the sqlite3_value* argument comes from the [sqlite3_column_value()] 2493** interface, then these routines should be called from the same thread 2494** that ran [sqlite3_column_value()]. 2495** 2496*/ 2497const void *sqlite3_value_blob(sqlite3_value*); 2498int sqlite3_value_bytes(sqlite3_value*); 2499int sqlite3_value_bytes16(sqlite3_value*); 2500double sqlite3_value_double(sqlite3_value*); 2501int sqlite3_value_int(sqlite3_value*); 2502sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 2503const unsigned char *sqlite3_value_text(sqlite3_value*); 2504const void *sqlite3_value_text16(sqlite3_value*); 2505const void *sqlite3_value_text16le(sqlite3_value*); 2506const void *sqlite3_value_text16be(sqlite3_value*); 2507int sqlite3_value_type(sqlite3_value*); 2508int sqlite3_value_numeric_type(sqlite3_value*); 2509 2510/* 2511** CAPI3REF: Obtain Aggregate Function Context {F16210} 2512** 2513** The implementation of aggregate SQL functions use this routine to allocate 2514** a structure for storing their state. 2515** {F16211} The first time the sqlite3_aggregate_context() routine is 2516** is called for a particular aggregate, SQLite allocates nBytes of memory 2517** zeros that memory, and returns a pointer to it. 2518** {F16212} On second and subsequent calls to sqlite3_aggregate_context() 2519** for the same aggregate function index, the same buffer is returned. {END} 2520** The implementation 2521** of the aggregate can use the returned buffer to accumulate data. 2522** 2523** {F16213} SQLite automatically frees the allocated buffer when the aggregate 2524** query concludes. {END} 2525** 2526** The first parameter should be a copy of the 2527** [sqlite3_context | SQL function context] that is the first 2528** parameter to the callback routine that implements the aggregate 2529** function. 2530** 2531** This routine must be called from the same thread in which 2532** the aggregate SQL function is running. 2533*/ 2534void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 2535 2536/* 2537** CAPI3REF: User Data For Functions {F16240} 2538** 2539** {F16241} The sqlite3_user_data() interface returns a copy of 2540** the pointer that was the pUserData parameter (the 5th parameter) 2541** of the the [sqlite3_create_function()] 2542** and [sqlite3_create_function16()] routines that originally 2543** registered the application defined function. {END} 2544** 2545** {U16243} This routine must be called from the same thread in which 2546** the application-defined function is running. 2547*/ 2548void *sqlite3_user_data(sqlite3_context*); 2549 2550/* 2551** CAPI3REF: Function Auxiliary Data {F16270} 2552** 2553** The following two functions may be used by scalar SQL functions to 2554** associate meta-data with argument values. If the same value is passed to 2555** multiple invocations of the same SQL function during query execution, under 2556** some circumstances the associated meta-data may be preserved. This may 2557** be used, for example, to add a regular-expression matching scalar 2558** function. The compiled version of the regular expression is stored as 2559** meta-data associated with the SQL value passed as the regular expression 2560** pattern. The compiled regular expression can be reused on multiple 2561** invocations of the same function so that the original pattern string 2562** does not need to be recompiled on each invocation. 2563** 2564** {F16271} 2565** The sqlite3_get_auxdata() interface returns a pointer to the meta-data 2566** associated by the sqlite3_set_auxdata() function with the Nth argument 2567** value to the application-defined function. 2568** {F16272} If no meta-data has been ever been set for the Nth 2569** argument of the function, or if the cooresponding function parameter 2570** has changed since the meta-data was set, then sqlite3_get_auxdata() 2571** returns a NULL pointer. 2572** 2573** {F16275} The sqlite3_set_auxdata() interface saves the meta-data 2574** pointed to by its 3rd parameter as the meta-data for the N-th 2575** argument of the application-defined function. {END} Subsequent 2576** calls to sqlite3_get_auxdata() might return this data, if it has 2577** not been destroyed. 2578** {F16277} If it is not NULL, SQLite will invoke the destructor 2579** function given by the 4th parameter to sqlite3_set_auxdata() on 2580** the meta-data when the corresponding function parameter changes 2581** or when the SQL statement completes, whichever comes first. {END} 2582** 2583** In practice, meta-data is preserved between function calls for 2584** expressions that are constant at compile time. This includes literal 2585** values and SQL variables. 2586** 2587** These routines must be called from the same thread in which 2588** the SQL function is running. 2589*/ 2590void *sqlite3_get_auxdata(sqlite3_context*, int N); 2591void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 2592 2593 2594/* 2595** CAPI3REF: Constants Defining Special Destructor Behavior {F10280} 2596** 2597** These are special value for the destructor that is passed in as the 2598** final argument to routines like [sqlite3_result_blob()]. If the destructor 2599** argument is SQLITE_STATIC, it means that the content pointer is constant 2600** and will never change. It does not need to be destroyed. The 2601** SQLITE_TRANSIENT value means that the content will likely change in 2602** the near future and that SQLite should make its own private copy of 2603** the content before returning. 2604** 2605** The typedef is necessary to work around problems in certain 2606** C++ compilers. See ticket #2191. 2607*/ 2608typedef void (*sqlite3_destructor_type)(void*); 2609#define SQLITE_STATIC ((sqlite3_destructor_type)0) 2610#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 2611 2612/* 2613** CAPI3REF: Setting The Result Of An SQL Function {F16400} 2614** 2615** These routines are used by the xFunc or xFinal callbacks that 2616** implement SQL functions and aggregates. See 2617** [sqlite3_create_function()] and [sqlite3_create_function16()] 2618** for additional information. 2619** 2620** These functions work very much like the 2621** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used 2622** to bind values to host parameters in prepared statements. 2623** Refer to the 2624** [sqlite3_bind_blob | sqlite3_bind_* documentation] for 2625** additional information. 2626** 2627** {F16402} The sqlite3_result_blob() interface sets the result from 2628** an application defined function to be the BLOB whose content is pointed 2629** to by the second parameter and which is N bytes long where N is the 2630** third parameter. 2631** {F16403} The sqlite3_result_zeroblob() inerfaces set the result of 2632** the application defined function to be a BLOB containing all zero 2633** bytes and N bytes in size, where N is the value of the 2nd parameter. 2634** 2635** {F16407} The sqlite3_result_double() interface sets the result from 2636** an application defined function to be a floating point value specified 2637** by its 2nd argument. 2638** 2639** {F16409} The sqlite3_result_error() and sqlite3_result_error16() functions 2640** cause the implemented SQL function to throw an exception. 2641** {F16411} SQLite uses the string pointed to by the 2642** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 2643** as the text of an error message. {F16412} SQLite interprets the error 2644** message string from sqlite3_result_error() as UTF8. {F16413} SQLite 2645** interprets the string from sqlite3_result_error16() as UTF16 in native 2646** byte order. {F16414} If the third parameter to sqlite3_result_error() 2647** or sqlite3_result_error16() is negative then SQLite takes as the error 2648** message all text up through the first zero character. 2649** {F16415} If the third parameter to sqlite3_result_error() or 2650** sqlite3_result_error16() is non-negative then SQLite takes that many 2651** bytes (not characters) from the 2nd parameter as the error message. 2652** {F16417} The sqlite3_result_error() and sqlite3_result_error16() 2653** routines make a copy private copy of the error message text before 2654** they return. {END} Hence, the calling function can deallocate or 2655** modify the text after they return without harm. 2656** 2657** {F16421} The sqlite3_result_toobig() interface causes SQLite 2658** to throw an error indicating that a string or BLOB is to long 2659** to represent. {F16422} The sqlite3_result_nomem() interface 2660** causes SQLite to throw an exception indicating that the a 2661** memory allocation failed. 2662** 2663** {F16431} The sqlite3_result_int() interface sets the return value 2664** of the application-defined function to be the 32-bit signed integer 2665** value given in the 2nd argument. 2666** {F16432} The sqlite3_result_int64() interface sets the return value 2667** of the application-defined function to be the 64-bit signed integer 2668** value given in the 2nd argument. 2669** 2670** {F16437} The sqlite3_result_null() interface sets the return value 2671** of the application-defined function to be NULL. 2672** 2673** {F16441} The sqlite3_result_text(), sqlite3_result_text16(), 2674** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 2675** set the return value of the application-defined function to be 2676** a text string which is represented as UTF-8, UTF-16 native byte order, 2677** UTF-16 little endian, or UTF-16 big endian, respectively. 2678** {F16442} SQLite takes the text result from the application from 2679** the 2nd parameter of the sqlite3_result_text* interfaces. 2680** {F16444} If the 3rd parameter to the sqlite3_result_text* interfaces 2681** is negative, then SQLite takes result text from the 2nd parameter 2682** through the first zero character. 2683** {F16447} If the 3rd parameter to the sqlite3_result_text* interfaces 2684** is non-negative, then as many bytes (not characters) of the text 2685** pointed to by the 2nd parameter are taken as the application-defined 2686** function result. 2687** {F16451} If the 4th parameter to the sqlite3_result_text* interfaces 2688** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 2689** function as the destructor on the text or blob result when it has 2690** finished using that result. 2691** {F16453} If the 4th parameter to the sqlite3_result_text* interfaces 2692** or sqlite3_result_blob is the special constant SQLITE_STATIC, then 2693** SQLite assumes that the text or blob result is constant space and 2694** does not copy the space or call a destructor when it has 2695** finished using that result. 2696** {F16454} If the 4th parameter to the sqlite3_result_text* interfaces 2697** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 2698** then SQLite makes a copy of the result into space obtained from 2699** from [sqlite3_malloc()] before it returns. 2700** 2701** {F16461} The sqlite3_result_value() interface sets the result of 2702** the application-defined function to be a copy the [sqlite3_value] 2703** object specified by the 2nd parameter. {F16463} The 2704** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 2705** so that [sqlite3_value] specified in the parameter may change or 2706** be deallocated after sqlite3_result_value() returns without harm. 2707** 2708** {U16491} These routines are called from within the different thread 2709** than the one containing the application-defined function that recieved 2710** the [sqlite3_context] pointer, the results are undefined. 2711*/ 2712void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 2713void sqlite3_result_double(sqlite3_context*, double); 2714void sqlite3_result_error(sqlite3_context*, const char*, int); 2715void sqlite3_result_error16(sqlite3_context*, const void*, int); 2716void sqlite3_result_error_toobig(sqlite3_context*); 2717void sqlite3_result_error_nomem(sqlite3_context*); 2718void sqlite3_result_int(sqlite3_context*, int); 2719void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 2720void sqlite3_result_null(sqlite3_context*); 2721void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 2722void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 2723void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 2724void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 2725void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 2726void sqlite3_result_zeroblob(sqlite3_context*, int n); 2727 2728/* 2729** CAPI3REF: Define New Collating Sequences {F16600} 2730** 2731** {F16601} 2732** These functions are used to add new collation sequences to the 2733** [sqlite3*] handle specified as the first argument. 2734** 2735** {F16602} 2736** The name of the new collation sequence is specified as a UTF-8 string 2737** for sqlite3_create_collation() and sqlite3_create_collation_v2() 2738** and a UTF-16 string for sqlite3_create_collation16(). {F16603} In all cases 2739** the name is passed as the second function argument. 2740** 2741** {F16604} 2742** The third argument may be one of the constants [SQLITE_UTF8], 2743** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied 2744** routine expects to be passed pointers to strings encoded using UTF-8, 2745** UTF-16 little-endian or UTF-16 big-endian respectively. {F16605} The 2746** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that 2747** the routine expects pointers to 16-bit word aligned strings 2748** of UTF16 in the native byte order of the host computer. 2749** 2750** {F16607} 2751** A pointer to the user supplied routine must be passed as the fifth 2752** argument. {F16609} If it is NULL, this is the same as deleting the collation 2753** sequence (so that SQLite cannot call it anymore). 2754** {F16611} Each time the application 2755** supplied function is invoked, it is passed a copy of the void* passed as 2756** the fourth argument to sqlite3_create_collation() or 2757** sqlite3_create_collation16() as its first parameter. 2758** 2759** {F16612} 2760** The remaining arguments to the application-supplied routine are two strings, 2761** each represented by a [length, data] pair and encoded in the encoding 2762** that was passed as the third argument when the collation sequence was 2763** registered. {END} The application defined collation routine should 2764** return negative, zero or positive if 2765** the first string is less than, equal to, or greater than the second 2766** string. i.e. (STRING1 - STRING2). 2767** 2768** {F16615} 2769** The sqlite3_create_collation_v2() works like sqlite3_create_collation() 2770** excapt that it takes an extra argument which is a destructor for 2771** the collation. {F16617} The destructor is called when the collation is 2772** destroyed and is passed a copy of the fourth parameter void* pointer 2773** of the sqlite3_create_collation_v2(). 2774** {F16618} Collations are destroyed when 2775** they are overridden by later calls to the collation creation functions 2776** or when the [sqlite3*] database handle is closed using [sqlite3_close()]. 2777*/ 2778int sqlite3_create_collation( 2779 sqlite3*, 2780 const char *zName, 2781 int eTextRep, 2782 void*, 2783 int(*xCompare)(void*,int,const void*,int,const void*) 2784); 2785int sqlite3_create_collation_v2( 2786 sqlite3*, 2787 const char *zName, 2788 int eTextRep, 2789 void*, 2790 int(*xCompare)(void*,int,const void*,int,const void*), 2791 void(*xDestroy)(void*) 2792); 2793int sqlite3_create_collation16( 2794 sqlite3*, 2795 const char *zName, 2796 int eTextRep, 2797 void*, 2798 int(*xCompare)(void*,int,const void*,int,const void*) 2799); 2800 2801/* 2802** CAPI3REF: Collation Needed Callbacks {F16700} 2803** 2804** {F16701} 2805** To avoid having to register all collation sequences before a database 2806** can be used, a single callback function may be registered with the 2807** database handle to be called whenever an undefined collation sequence is 2808** required. 2809** 2810** {F16702} 2811** If the function is registered using the sqlite3_collation_needed() API, 2812** then it is passed the names of undefined collation sequences as strings 2813** encoded in UTF-8. {F16703} If sqlite3_collation_needed16() is used, the names 2814** are passed as UTF-16 in machine native byte order. {F16704} A call to either 2815** function replaces any existing callback. 2816** 2817** {F16705} When the callback is invoked, the first argument passed is a copy 2818** of the second argument to sqlite3_collation_needed() or 2819** sqlite3_collation_needed16(). {F16706} The second argument is the database 2820** handle. {F16707} The third argument is one of [SQLITE_UTF8], 2821** [SQLITE_UTF16BE], or [SQLITE_UTF16LE], indicating the most 2822** desirable form of the collation sequence function required. 2823** {F16708} The fourth parameter is the name of the 2824** required collation sequence. {END} 2825** 2826** The callback function should register the desired collation using 2827** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 2828** [sqlite3_create_collation_v2()]. 2829*/ 2830int sqlite3_collation_needed( 2831 sqlite3*, 2832 void*, 2833 void(*)(void*,sqlite3*,int eTextRep,const char*) 2834); 2835int sqlite3_collation_needed16( 2836 sqlite3*, 2837 void*, 2838 void(*)(void*,sqlite3*,int eTextRep,const void*) 2839); 2840 2841/* 2842** Specify the key for an encrypted database. This routine should be 2843** called right after sqlite3_open(). 2844** 2845** The code to implement this API is not available in the public release 2846** of SQLite. 2847*/ 2848int sqlite3_key( 2849 sqlite3 *db, /* Database to be rekeyed */ 2850 const void *pKey, int nKey /* The key */ 2851); 2852 2853/* 2854** Change the key on an open database. If the current database is not 2855** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 2856** database is decrypted. 2857** 2858** The code to implement this API is not available in the public release 2859** of SQLite. 2860*/ 2861int sqlite3_rekey( 2862 sqlite3 *db, /* Database to be rekeyed */ 2863 const void *pKey, int nKey /* The new key */ 2864); 2865 2866/* 2867** CAPI3REF: Suspend Execution For A Short Time {F10530} 2868** 2869** {F10531} The sqlite3_sleep() function 2870** causes the current thread to suspend execution 2871** for at least a number of milliseconds specified in its parameter. 2872** 2873** {F10532} If the operating system does not support sleep requests with 2874** millisecond time resolution, then the time will be rounded up to 2875** the nearest second. {F10533} The number of milliseconds of sleep actually 2876** requested from the operating system is returned. 2877** 2878** {F10534} SQLite implements this interface by calling the xSleep() 2879** method of the default [sqlite3_vfs] object. {END} 2880*/ 2881int sqlite3_sleep(int); 2882 2883/* 2884** CAPI3REF: Name Of The Folder Holding Temporary Files {F10310} 2885** 2886** If this global variable is made to point to a string which is 2887** the name of a folder (a.ka. directory), then all temporary files 2888** created by SQLite will be placed in that directory. If this variable 2889** is NULL pointer, then SQLite does a search for an appropriate temporary 2890** file directory. 2891** 2892** It is not safe to modify this variable once a database connection 2893** has been opened. It is intended that this variable be set once 2894** as part of process initialization and before any SQLite interface 2895** routines have been call and remain unchanged thereafter. 2896*/ 2897SQLITE_EXTERN char *sqlite3_temp_directory; 2898 2899/* 2900** CAPI3REF: Test To See If The Database Is In Auto-Commit Mode {F12930} 2901** 2902** {F12931} The sqlite3_get_autocommit() interfaces returns non-zero or 2903** zero if the given database connection is or is not in autocommit mode, 2904** respectively. {F12932} Autocommit mode is on 2905** by default. {F12933} Autocommit mode is disabled by a BEGIN statement. 2906** {F12934} Autocommit mode is reenabled by a COMMIT or ROLLBACK. {END} 2907** 2908** If certain kinds of errors occur on a statement within a multi-statement 2909** transactions (errors including [SQLITE_FULL], [SQLITE_IOERR], 2910** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 2911** transaction might be rolled back automatically. {F12935} The only way to 2912** find out if SQLite automatically rolled back the transaction after 2913** an error is to use this function. {END} 2914** 2915** {U12936} If another thread changes the autocommit status of the database 2916** connection while this routine is running, then the return value 2917** is undefined. {END} 2918*/ 2919int sqlite3_get_autocommit(sqlite3*); 2920 2921/* 2922** CAPI3REF: Find The Database Handle Of A Prepared Statement {F13120} 2923** 2924** {F13121} The sqlite3_db_handle interface 2925** returns the [sqlite3*] database handle to which a 2926** [sqlite3_stmt | prepared statement] belongs. 2927** {F13122} the database handle returned by sqlite3_db_handle 2928** is the same database handle that was 2929** the first argument to the [sqlite3_prepare_v2()] or its variants 2930** that was used to create the statement in the first place. 2931*/ 2932sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 2933 2934 2935/* 2936** CAPI3REF: Commit And Rollback Notification Callbacks {F12950} 2937** 2938** {F12951} The sqlite3_commit_hook() interface registers a callback 2939** function to be invoked whenever a transaction is committed. 2940** {F12952} Any callback set by a previous call to sqlite3_commit_hook() 2941** for the same database connection is overridden. 2942** {F12953} The sqlite3_rollback_hook() interface registers a callback 2943** function to be invoked whenever a transaction is committed. 2944** {F12954} Any callback set by a previous call to sqlite3_commit_hook() 2945** for the same database connection is overridden. 2946** {F12956} The pArg argument is passed through 2947** to the callback. {F12957} If the callback on a commit hook function 2948** returns non-zero, then the commit is converted into a rollback. 2949** 2950** {F12958} If another function was previously registered, its 2951** pArg value is returned. Otherwise NULL is returned. 2952** 2953** {F12959} Registering a NULL function disables the callback. 2954** 2955** {F12961} For the purposes of this API, a transaction is said to have been 2956** rolled back if an explicit "ROLLBACK" statement is executed, or 2957** an error or constraint causes an implicit rollback to occur. 2958** {F12962} The rollback callback is not invoked if a transaction is 2959** automatically rolled back because the database connection is closed. 2960** {F12964} The rollback callback is not invoked if a transaction is 2961** rolled back because a commit callback returned non-zero. 2962** <todo> Check on this </todo> {END} 2963** 2964** These are experimental interfaces and are subject to change. 2965*/ 2966void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 2967void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 2968 2969/* 2970** CAPI3REF: Data Change Notification Callbacks {F12970} 2971** 2972** {F12971} The sqlite3_update_hook() interface 2973** registers a callback function with the database connection identified by the 2974** first argument to be invoked whenever a row is updated, inserted or deleted. 2975** {F12972} Any callback set by a previous call to this function for the same 2976** database connection is overridden. 2977** 2978** {F12974} The second argument is a pointer to the function to invoke when a 2979** row is updated, inserted or deleted. 2980** {F12976} The first argument to the callback is 2981** a copy of the third argument to sqlite3_update_hook(). 2982** {F12977} The second callback 2983** argument is one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 2984** depending on the operation that caused the callback to be invoked. 2985** {F12978} The third and 2986** fourth arguments to the callback contain pointers to the database and 2987** table name containing the affected row. 2988** {F12979} The final callback parameter is 2989** the rowid of the row. 2990** {F12981} In the case of an update, this is the rowid after 2991** the update takes place. 2992** 2993** {F12983} The update hook is not invoked when internal system tables are 2994** modified (i.e. sqlite_master and sqlite_sequence). 2995** 2996** {F12984} If another function was previously registered, its pArg value 2997** is returned. {F12985} Otherwise NULL is returned. 2998*/ 2999void *sqlite3_update_hook( 3000 sqlite3*, 3001 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 3002 void* 3003); 3004 3005/* 3006** CAPI3REF: Enable Or Disable Shared Pager Cache {F10330} 3007** 3008** {F10331} 3009** This routine enables or disables the sharing of the database cache 3010** and schema data structures between connections to the same database. 3011** {F10332} 3012** Sharing is enabled if the argument is true and disabled if the argument 3013** is false. 3014** 3015** {F10333} Cache sharing is enabled and disabled 3016** for an entire process. {END} This is a change as of SQLite version 3.5.0. 3017** In prior versions of SQLite, sharing was 3018** enabled or disabled for each thread separately. 3019** 3020** {F10334} 3021** The cache sharing mode set by this interface effects all subsequent 3022** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 3023** {F10335} Existing database connections continue use the sharing mode 3024** that was in effect at the time they were opened. {END} 3025** 3026** Virtual tables cannot be used with a shared cache. {F10336} When shared 3027** cache is enabled, the [sqlite3_create_module()] API used to register 3028** virtual tables will always return an error. {END} 3029** 3030** {F10337} This routine returns [SQLITE_OK] if shared cache was 3031** enabled or disabled successfully. {F10338} An [SQLITE_ERROR | error code] 3032** is returned otherwise. {END} 3033** 3034** {F10339} Shared cache is disabled by default. {END} But this might change in 3035** future releases of SQLite. Applications that care about shared 3036** cache setting should set it explicitly. 3037*/ 3038int sqlite3_enable_shared_cache(int); 3039 3040/* 3041** CAPI3REF: Attempt To Free Heap Memory {F17340} 3042** 3043** {F17341} The sqlite3_release_memory() interface attempts to 3044** free N bytes of heap memory by deallocating non-essential memory 3045** allocations held by the database labrary. {END} Memory used 3046** to cache database pages to improve performance is an example of 3047** non-essential memory. {F16342} sqlite3_release_memory() returns 3048** the number of bytes actually freed, which might be more or less 3049** than the amount requested. 3050*/ 3051int sqlite3_release_memory(int); 3052 3053/* 3054** CAPI3REF: Impose A Limit On Heap Size {F17350} 3055** 3056** {F16351} The sqlite3_soft_heap_limit() interface 3057** places a "soft" limit on the amount of heap memory that may be allocated 3058** by SQLite. {F16352} If an internal allocation is requested 3059** that would exceed the soft heap limit, [sqlite3_release_memory()] is 3060** invoked one or more times to free up some space before the allocation 3061** is made. {END} 3062** 3063** {F16353} The limit is called "soft", because if 3064** [sqlite3_release_memory()] cannot 3065** free sufficient memory to prevent the limit from being exceeded, 3066** the memory is allocated anyway and the current operation proceeds. 3067** 3068** {F16354} 3069** A negative or zero value for N means that there is no soft heap limit and 3070** [sqlite3_release_memory()] will only be called when memory is exhausted. 3071** {F16355} The default value for the soft heap limit is zero. 3072** 3073** SQLite makes a best effort to honor the soft heap limit. 3074** {F16356} But if the soft heap limit cannot honored, execution will 3075** continue without error or notification. {END} This is why the limit is 3076** called a "soft" limit. It is advisory only. 3077** 3078** Prior to SQLite version 3.5.0, this routine only constrained the memory 3079** allocated by a single thread - the same thread in which this routine 3080** runs. Beginning with SQLite version 3.5.0, the soft heap limit is 3081** applied to all threads. {F16357} The value specified for the soft heap limit 3082** is an upper bound on the total memory allocation for all threads. {END} In 3083** version 3.5.0 there is no mechanism for limiting the heap usage for 3084** individual threads. 3085*/ 3086void sqlite3_soft_heap_limit(int); 3087 3088/* 3089** CAPI3REF: Extract Metadata About A Column Of A Table {F12850} 3090** 3091** This routine 3092** returns meta-data about a specific column of a specific database 3093** table accessible using the connection handle passed as the first function 3094** argument. 3095** 3096** The column is identified by the second, third and fourth parameters to 3097** this function. The second parameter is either the name of the database 3098** (i.e. "main", "temp" or an attached database) containing the specified 3099** table or NULL. If it is NULL, then all attached databases are searched 3100** for the table using the same algorithm as the database engine uses to 3101** resolve unqualified table references. 3102** 3103** The third and fourth parameters to this function are the table and column 3104** name of the desired column, respectively. Neither of these parameters 3105** may be NULL. 3106** 3107** Meta information is returned by writing to the memory locations passed as 3108** the 5th and subsequent parameters to this function. Any of these 3109** arguments may be NULL, in which case the corresponding element of meta 3110** information is ommitted. 3111** 3112** <pre> 3113** Parameter Output Type Description 3114** ----------------------------------- 3115** 3116** 5th const char* Data type 3117** 6th const char* Name of the default collation sequence 3118** 7th int True if the column has a NOT NULL constraint 3119** 8th int True if the column is part of the PRIMARY KEY 3120** 9th int True if the column is AUTOINCREMENT 3121** </pre> 3122** 3123** 3124** The memory pointed to by the character pointers returned for the 3125** declaration type and collation sequence is valid only until the next 3126** call to any sqlite API function. 3127** 3128** If the specified table is actually a view, then an error is returned. 3129** 3130** If the specified column is "rowid", "oid" or "_rowid_" and an 3131** INTEGER PRIMARY KEY column has been explicitly declared, then the output 3132** parameters are set for the explicitly declared column. If there is no 3133** explicitly declared IPK column, then the output parameters are set as 3134** follows: 3135** 3136** <pre> 3137** data type: "INTEGER" 3138** collation sequence: "BINARY" 3139** not null: 0 3140** primary key: 1 3141** auto increment: 0 3142** </pre> 3143** 3144** This function may load one or more schemas from database files. If an 3145** error occurs during this process, or if the requested table or column 3146** cannot be found, an SQLITE error code is returned and an error message 3147** left in the database handle (to be retrieved using sqlite3_errmsg()). 3148** 3149** This API is only available if the library was compiled with the 3150** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined. 3151*/ 3152int sqlite3_table_column_metadata( 3153 sqlite3 *db, /* Connection handle */ 3154 const char *zDbName, /* Database name or NULL */ 3155 const char *zTableName, /* Table name */ 3156 const char *zColumnName, /* Column name */ 3157 char const **pzDataType, /* OUTPUT: Declared data type */ 3158 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 3159 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 3160 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 3161 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 3162); 3163 3164/* 3165** CAPI3REF: Load An Extension {F12600} 3166** 3167** {F12601} The sqlite3_load_extension() interface 3168** attempts to load an SQLite extension library contained in the file 3169** zFile. {F12602} The entry point is zProc. {F12603} zProc may be 0 3170** in which case the name of the entry point defaults 3171** to "sqlite3_extension_init". 3172** 3173** {F12604} The sqlite3_load_extension() interface shall 3174** return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 3175** 3176** {F12605} 3177** If an error occurs and pzErrMsg is not 0, then the 3178** sqlite3_load_extension() interface shall attempt to fill *pzErrMsg with 3179** error message text stored in memory obtained from [sqlite3_malloc()]. 3180** {END} The calling function should free this memory 3181** by calling [sqlite3_free()]. 3182** 3183** {F12606} 3184** Extension loading must be enabled using [sqlite3_enable_load_extension()] 3185** prior to calling this API or an error will be returned. 3186*/ 3187int sqlite3_load_extension( 3188 sqlite3 *db, /* Load the extension into this database connection */ 3189 const char *zFile, /* Name of the shared library containing extension */ 3190 const char *zProc, /* Entry point. Derived from zFile if 0 */ 3191 char **pzErrMsg /* Put error message here if not 0 */ 3192); 3193 3194/* 3195** CAPI3REF: Enable Or Disable Extension Loading {F12620} 3196** 3197** So as not to open security holes in older applications that are 3198** unprepared to deal with extension loading, and as a means of disabling 3199** extension loading while evaluating user-entered SQL, the following 3200** API is provided to turn the [sqlite3_load_extension()] mechanism on and 3201** off. {F12622} It is off by default. {END} See ticket #1863. 3202** 3203** {F12621} Call the sqlite3_enable_load_extension() routine 3204** with onoff==1 to turn extension loading on 3205** and call it with onoff==0 to turn it back off again. {END} 3206*/ 3207int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 3208 3209/* 3210** CAPI3REF: Make Arrangements To Automatically Load An Extension {F12640} 3211** 3212** {F12641} This function 3213** registers an extension entry point that is automatically invoked 3214** whenever a new database connection is opened using 3215** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()]. {END} 3216** 3217** This API can be invoked at program startup in order to register 3218** one or more statically linked extensions that will be available 3219** to all new database connections. 3220** 3221** {F12642} Duplicate extensions are detected so calling this routine multiple 3222** times with the same extension is harmless. 3223** 3224** {F12643} This routine stores a pointer to the extension in an array 3225** that is obtained from sqlite_malloc(). {END} If you run a memory leak 3226** checker on your program and it reports a leak because of this 3227** array, then invoke [sqlite3_reset_auto_extension()] prior 3228** to shutdown to free the memory. 3229** 3230** {F12644} Automatic extensions apply across all threads. {END} 3231** 3232** This interface is experimental and is subject to change or 3233** removal in future releases of SQLite. 3234*/ 3235int sqlite3_auto_extension(void *xEntryPoint); 3236 3237 3238/* 3239** CAPI3REF: Reset Automatic Extension Loading {F12660} 3240** 3241** {F12661} This function disables all previously registered 3242** automatic extensions. {END} This 3243** routine undoes the effect of all prior [sqlite3_automatic_extension()] 3244** calls. 3245** 3246** {F12662} This call disabled automatic extensions in all threads. {END} 3247** 3248** This interface is experimental and is subject to change or 3249** removal in future releases of SQLite. 3250*/ 3251void sqlite3_reset_auto_extension(void); 3252 3253 3254/* 3255****** EXPERIMENTAL - subject to change without notice ************** 3256** 3257** The interface to the virtual-table mechanism is currently considered 3258** to be experimental. The interface might change in incompatible ways. 3259** If this is a problem for you, do not use the interface at this time. 3260** 3261** When the virtual-table mechanism stablizes, we will declare the 3262** interface fixed, support it indefinitely, and remove this comment. 3263*/ 3264 3265/* 3266** Structures used by the virtual table interface 3267*/ 3268typedef struct sqlite3_vtab sqlite3_vtab; 3269typedef struct sqlite3_index_info sqlite3_index_info; 3270typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 3271typedef struct sqlite3_module sqlite3_module; 3272 3273/* 3274** A module is a class of virtual tables. Each module is defined 3275** by an instance of the following structure. This structure consists 3276** mostly of methods for the module. 3277*/ 3278struct sqlite3_module { 3279 int iVersion; 3280 int (*xCreate)(sqlite3*, void *pAux, 3281 int argc, const char *const*argv, 3282 sqlite3_vtab **ppVTab, char**); 3283 int (*xConnect)(sqlite3*, void *pAux, 3284 int argc, const char *const*argv, 3285 sqlite3_vtab **ppVTab, char**); 3286 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 3287 int (*xDisconnect)(sqlite3_vtab *pVTab); 3288 int (*xDestroy)(sqlite3_vtab *pVTab); 3289 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 3290 int (*xClose)(sqlite3_vtab_cursor*); 3291 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 3292 int argc, sqlite3_value **argv); 3293 int (*xNext)(sqlite3_vtab_cursor*); 3294 int (*xEof)(sqlite3_vtab_cursor*); 3295 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 3296 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 3297 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 3298 int (*xBegin)(sqlite3_vtab *pVTab); 3299 int (*xSync)(sqlite3_vtab *pVTab); 3300 int (*xCommit)(sqlite3_vtab *pVTab); 3301 int (*xRollback)(sqlite3_vtab *pVTab); 3302 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 3303 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 3304 void **ppArg); 3305 3306 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 3307}; 3308 3309/* 3310** The sqlite3_index_info structure and its substructures is used to 3311** pass information into and receive the reply from the xBestIndex 3312** method of an sqlite3_module. The fields under **Inputs** are the 3313** inputs to xBestIndex and are read-only. xBestIndex inserts its 3314** results into the **Outputs** fields. 3315** 3316** The aConstraint[] array records WHERE clause constraints of the 3317** form: 3318** 3319** column OP expr 3320** 3321** Where OP is =, <, <=, >, or >=. 3322** The particular operator is stored 3323** in aConstraint[].op. The index of the column is stored in 3324** aConstraint[].iColumn. aConstraint[].usable is TRUE if the 3325** expr on the right-hand side can be evaluated (and thus the constraint 3326** is usable) and false if it cannot. 3327** 3328** The optimizer automatically inverts terms of the form "expr OP column" 3329** and makes other simplifications to the WHERE clause in an attempt to 3330** get as many WHERE clause terms into the form shown above as possible. 3331** The aConstraint[] array only reports WHERE clause terms in the correct 3332** form that refer to the particular virtual table being queried. 3333** 3334** Information about the ORDER BY clause is stored in aOrderBy[]. 3335** Each term of aOrderBy records a column of the ORDER BY clause. 3336** 3337** The xBestIndex method must fill aConstraintUsage[] with information 3338** about what parameters to pass to xFilter. If argvIndex>0 then 3339** the right-hand side of the corresponding aConstraint[] is evaluated 3340** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit 3341** is true, then the constraint is assumed to be fully handled by the 3342** virtual table and is not checked again by SQLite. 3343** 3344** The idxNum and idxPtr values are recorded and passed into xFilter. 3345** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. 3346** 3347** The orderByConsumed means that output from xFilter will occur in 3348** the correct order to satisfy the ORDER BY clause so that no separate 3349** sorting step is required. 3350** 3351** The estimatedCost value is an estimate of the cost of doing the 3352** particular lookup. A full scan of a table with N entries should have 3353** a cost of N. A binary search of a table of N entries should have a 3354** cost of approximately log(N). 3355*/ 3356struct sqlite3_index_info { 3357 /* Inputs */ 3358 int nConstraint; /* Number of entries in aConstraint */ 3359 struct sqlite3_index_constraint { 3360 int iColumn; /* Column on left-hand side of constraint */ 3361 unsigned char op; /* Constraint operator */ 3362 unsigned char usable; /* True if this constraint is usable */ 3363 int iTermOffset; /* Used internally - xBestIndex should ignore */ 3364 } *aConstraint; /* Table of WHERE clause constraints */ 3365 int nOrderBy; /* Number of terms in the ORDER BY clause */ 3366 struct sqlite3_index_orderby { 3367 int iColumn; /* Column number */ 3368 unsigned char desc; /* True for DESC. False for ASC. */ 3369 } *aOrderBy; /* The ORDER BY clause */ 3370 3371 /* Outputs */ 3372 struct sqlite3_index_constraint_usage { 3373 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 3374 unsigned char omit; /* Do not code a test for this constraint */ 3375 } *aConstraintUsage; 3376 int idxNum; /* Number used to identify the index */ 3377 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 3378 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 3379 int orderByConsumed; /* True if output is already ordered */ 3380 double estimatedCost; /* Estimated cost of using this index */ 3381}; 3382#define SQLITE_INDEX_CONSTRAINT_EQ 2 3383#define SQLITE_INDEX_CONSTRAINT_GT 4 3384#define SQLITE_INDEX_CONSTRAINT_LE 8 3385#define SQLITE_INDEX_CONSTRAINT_LT 16 3386#define SQLITE_INDEX_CONSTRAINT_GE 32 3387#define SQLITE_INDEX_CONSTRAINT_MATCH 64 3388 3389/* 3390** This routine is used to register a new module name with an SQLite 3391** connection. Module names must be registered before creating new 3392** virtual tables on the module, or before using preexisting virtual 3393** tables of the module. 3394*/ 3395int sqlite3_create_module( 3396 sqlite3 *db, /* SQLite connection to register module with */ 3397 const char *zName, /* Name of the module */ 3398 const sqlite3_module *, /* Methods for the module */ 3399 void * /* Client data for xCreate/xConnect */ 3400); 3401 3402/* 3403** This routine is identical to the sqlite3_create_module() method above, 3404** except that it allows a destructor function to be specified. It is 3405** even more experimental than the rest of the virtual tables API. 3406*/ 3407int sqlite3_create_module_v2( 3408 sqlite3 *db, /* SQLite connection to register module with */ 3409 const char *zName, /* Name of the module */ 3410 const sqlite3_module *, /* Methods for the module */ 3411 void *, /* Client data for xCreate/xConnect */ 3412 void(*xDestroy)(void*) /* Module destructor function */ 3413); 3414 3415/* 3416** Every module implementation uses a subclass of the following structure 3417** to describe a particular instance of the module. Each subclass will 3418** be tailored to the specific needs of the module implementation. The 3419** purpose of this superclass is to define certain fields that are common 3420** to all module implementations. 3421** 3422** Virtual tables methods can set an error message by assigning a 3423** string obtained from sqlite3_mprintf() to zErrMsg. The method should 3424** take care that any prior string is freed by a call to sqlite3_free() 3425** prior to assigning a new string to zErrMsg. After the error message 3426** is delivered up to the client application, the string will be automatically 3427** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note 3428** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field 3429** since virtual tables are commonly implemented in loadable extensions which 3430** do not have access to sqlite3MPrintf() or sqlite3Free(). 3431*/ 3432struct sqlite3_vtab { 3433 const sqlite3_module *pModule; /* The module for this virtual table */ 3434 int nRef; /* Used internally */ 3435 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 3436 /* Virtual table implementations will typically add additional fields */ 3437}; 3438 3439/* Every module implementation uses a subclass of the following structure 3440** to describe cursors that point into the virtual table and are used 3441** to loop through the virtual table. Cursors are created using the 3442** xOpen method of the module. Each module implementation will define 3443** the content of a cursor structure to suit its own needs. 3444** 3445** This superclass exists in order to define fields of the cursor that 3446** are common to all implementations. 3447*/ 3448struct sqlite3_vtab_cursor { 3449 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 3450 /* Virtual table implementations will typically add additional fields */ 3451}; 3452 3453/* 3454** The xCreate and xConnect methods of a module use the following API 3455** to declare the format (the names and datatypes of the columns) of 3456** the virtual tables they implement. 3457*/ 3458int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); 3459 3460/* 3461** Virtual tables can provide alternative implementations of functions 3462** using the xFindFunction method. But global versions of those functions 3463** must exist in order to be overloaded. 3464** 3465** This API makes sure a global version of a function with a particular 3466** name and number of parameters exists. If no such function exists 3467** before this API is called, a new function is created. The implementation 3468** of the new function always causes an exception to be thrown. So 3469** the new function is not good for anything by itself. Its only 3470** purpose is to be a place-holder function that can be overloaded 3471** by virtual tables. 3472** 3473** This API should be considered part of the virtual table interface, 3474** which is experimental and subject to change. 3475*/ 3476int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 3477 3478/* 3479** The interface to the virtual-table mechanism defined above (back up 3480** to a comment remarkably similar to this one) is currently considered 3481** to be experimental. The interface might change in incompatible ways. 3482** If this is a problem for you, do not use the interface at this time. 3483** 3484** When the virtual-table mechanism stabilizes, we will declare the 3485** interface fixed, support it indefinitely, and remove this comment. 3486** 3487****** EXPERIMENTAL - subject to change without notice ************** 3488*/ 3489 3490/* 3491** CAPI3REF: A Handle To An Open BLOB {F17800} 3492** 3493** An instance of the following opaque structure is used to 3494** represent an blob-handle. A blob-handle is created by 3495** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()]. 3496** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 3497** can be used to read or write small subsections of the blob. 3498** The [sqlite3_blob_bytes()] interface returns the size of the 3499** blob in bytes. 3500*/ 3501typedef struct sqlite3_blob sqlite3_blob; 3502 3503/* 3504** CAPI3REF: Open A BLOB For Incremental I/O {F17810} 3505** 3506** {F17811} This interfaces opens a handle to the blob located 3507** in row iRow,, column zColumn, table zTable in database zDb; 3508** in other words, the same blob that would be selected by: 3509** 3510** <pre> 3511** SELECT zColumn FROM zDb.zTable WHERE rowid = iRow; 3512** </pre> {END} 3513** 3514** {F17812} If the flags parameter is non-zero, the blob is opened for 3515** read and write access. If it is zero, the blob is opened for read 3516** access. {END} 3517** 3518** {F17813} On success, [SQLITE_OK] is returned and the new 3519** [sqlite3_blob | blob handle] is written to *ppBlob. 3520** {F17814} Otherwise an error code is returned and 3521** any value written to *ppBlob should not be used by the caller. 3522** {F17815} This function sets the database-handle error code and message 3523** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. 3524** <todo>We should go through and mark all interfaces that behave this 3525** way with a similar statement</todo> 3526*/ 3527int sqlite3_blob_open( 3528 sqlite3*, 3529 const char *zDb, 3530 const char *zTable, 3531 const char *zColumn, 3532 sqlite3_int64 iRow, 3533 int flags, 3534 sqlite3_blob **ppBlob 3535); 3536 3537/* 3538** CAPI3REF: Close A BLOB Handle {F17830} 3539** 3540** Close an open [sqlite3_blob | blob handle]. 3541** 3542** {F17831} Closing a BLOB shall cause the current transaction to commit 3543** if there are no other BLOBs, no pending prepared statements, and the 3544** database connection is in autocommit mode. 3545** {F17832} If any writes were made to the BLOB, they might be held in cache 3546** until the close operation if they will fit. {END} 3547** Closing the BLOB often forces the changes 3548** out to disk and so if any I/O errors occur, they will likely occur 3549** at the time when the BLOB is closed. {F17833} Any errors that occur during 3550** closing are reported as a non-zero return value. 3551** 3552** {F17839} The BLOB is closed unconditionally. Even if this routine returns 3553** an error code, the BLOB is still closed. 3554*/ 3555int sqlite3_blob_close(sqlite3_blob *); 3556 3557/* 3558** CAPI3REF: Return The Size Of An Open BLOB {F17805} 3559** 3560** {F16806} Return the size in bytes of the blob accessible via the open 3561** [sqlite3_blob | blob-handle] passed as an argument. 3562*/ 3563int sqlite3_blob_bytes(sqlite3_blob *); 3564 3565/* 3566** CAPI3REF: Read Data From A BLOB Incrementally {F17850} 3567** 3568** This function is used to read data from an open 3569** [sqlite3_blob | blob-handle] into a caller supplied buffer. 3570** {F17851} n bytes of data are copied into buffer 3571** z from the open blob, starting at offset iOffset. 3572** 3573** {F17852} If offset iOffset is less than n bytes from the end of the blob, 3574** [SQLITE_ERROR] is returned and no data is read. {F17853} If n is 3575** less than zero [SQLITE_ERROR] is returned and no data is read. 3576** 3577** {F17854} On success, SQLITE_OK is returned. Otherwise, an 3578** [SQLITE_ERROR | SQLite error code] or an 3579** [SQLITE_IOERR_READ | extended error code] is returned. 3580*/ 3581int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset); 3582 3583/* 3584** CAPI3REF: Write Data Into A BLOB Incrementally {F17870} 3585** 3586** This function is used to write data into an open 3587** [sqlite3_blob | blob-handle] from a user supplied buffer. 3588** {F17871} n bytes of data are copied from the buffer 3589** pointed to by z into the open blob, starting at offset iOffset. 3590** 3591** {F17872} If the [sqlite3_blob | blob-handle] passed as the first argument 3592** was not opened for writing (the flags parameter to [sqlite3_blob_open()] 3593*** was zero), this function returns [SQLITE_READONLY]. 3594** 3595** {F17873} This function may only modify the contents of the blob; it is 3596** not possible to increase the size of a blob using this API. 3597** {F17874} If offset iOffset is less than n bytes from the end of the blob, 3598** [SQLITE_ERROR] is returned and no data is written. {F17875} If n is 3599** less than zero [SQLITE_ERROR] is returned and no data is written. 3600** 3601** {F17876} On success, SQLITE_OK is returned. Otherwise, an 3602** [SQLITE_ERROR | SQLite error code] or an 3603** [SQLITE_IOERR_READ | extended error code] is returned. 3604*/ 3605int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 3606 3607/* 3608** CAPI3REF: Virtual File System Objects {F11200} 3609** 3610** A virtual filesystem (VFS) is an [sqlite3_vfs] object 3611** that SQLite uses to interact 3612** with the underlying operating system. Most builds come with a 3613** single default VFS that is appropriate for the host computer. 3614** New VFSes can be registered and existing VFSes can be unregistered. 3615** The following interfaces are provided. 3616** 3617** {F11201} The sqlite3_vfs_find() interface returns a pointer to 3618** a VFS given its name. {F11202} Names are case sensitive. 3619** {F11203} Names are zero-terminated UTF-8 strings. 3620** {F11204} If there is no match, a NULL 3621** pointer is returned. {F11205} If zVfsName is NULL then the default 3622** VFS is returned. {END} 3623** 3624** {F11210} New VFSes are registered with sqlite3_vfs_register(). 3625** {F11211} Each new VFS becomes the default VFS if the makeDflt flag is set. 3626** {F11212} The same VFS can be registered multiple times without injury. 3627** {F11213} To make an existing VFS into the default VFS, register it again 3628** with the makeDflt flag set. {U11214} If two different VFSes with the 3629** same name are registered, the behavior is undefined. {U11215} If a 3630** VFS is registered with a name that is NULL or an empty string, 3631** then the behavior is undefined. 3632** 3633** {F11220} Unregister a VFS with the sqlite3_vfs_unregister() interface. 3634** {F11221} If the default VFS is unregistered, another VFS is chosen as 3635** the default. The choice for the new VFS is arbitrary. 3636*/ 3637sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 3638int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 3639int sqlite3_vfs_unregister(sqlite3_vfs*); 3640 3641/* 3642** CAPI3REF: Mutexes {F17000} 3643** 3644** The SQLite core uses these routines for thread 3645** synchronization. Though they are intended for internal 3646** use by SQLite, code that links against SQLite is 3647** permitted to use any of these routines. 3648** 3649** The SQLite source code contains multiple implementations 3650** of these mutex routines. An appropriate implementation 3651** is selected automatically at compile-time. The following 3652** implementations are available in the SQLite core: 3653** 3654** <ul> 3655** <li> SQLITE_MUTEX_OS2 3656** <li> SQLITE_MUTEX_PTHREAD 3657** <li> SQLITE_MUTEX_W32 3658** <li> SQLITE_MUTEX_NOOP 3659** </ul> 3660** 3661** The SQLITE_MUTEX_NOOP implementation is a set of routines 3662** that does no real locking and is appropriate for use in 3663** a single-threaded application. The SQLITE_MUTEX_OS2, 3664** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations 3665** are appropriate for use on os/2, unix, and windows. 3666** 3667** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 3668** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 3669** implementation is included with the library. The 3670** mutex interface routines defined here become external 3671** references in the SQLite library for which implementations 3672** must be provided by the application. This facility allows an 3673** application that links against SQLite to provide its own mutex 3674** implementation without having to modify the SQLite core. 3675** 3676** {F17011} The sqlite3_mutex_alloc() routine allocates a new 3677** mutex and returns a pointer to it. {F17012} If it returns NULL 3678** that means that a mutex could not be allocated. {F17013} SQLite 3679** will unwind its stack and return an error. {F17014} The argument 3680** to sqlite3_mutex_alloc() is one of these integer constants: 3681** 3682** <ul> 3683** <li> SQLITE_MUTEX_FAST 3684** <li> SQLITE_MUTEX_RECURSIVE 3685** <li> SQLITE_MUTEX_STATIC_MASTER 3686** <li> SQLITE_MUTEX_STATIC_MEM 3687** <li> SQLITE_MUTEX_STATIC_MEM2 3688** <li> SQLITE_MUTEX_STATIC_PRNG 3689** <li> SQLITE_MUTEX_STATIC_LRU 3690** </ul> {END} 3691** 3692** {F17015} The first two constants cause sqlite3_mutex_alloc() to create 3693** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 3694** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} 3695** The mutex implementation does not need to make a distinction 3696** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 3697** not want to. {F17016} But SQLite will only request a recursive mutex in 3698** cases where it really needs one. {END} If a faster non-recursive mutex 3699** implementation is available on the host platform, the mutex subsystem 3700** might return such a mutex in response to SQLITE_MUTEX_FAST. 3701** 3702** {F17017} The other allowed parameters to sqlite3_mutex_alloc() each return 3703** a pointer to a static preexisting mutex. {END} Four static mutexes are 3704** used by the current version of SQLite. Future versions of SQLite 3705** may add additional static mutexes. Static mutexes are for internal 3706** use by SQLite only. Applications that use SQLite mutexes should 3707** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 3708** SQLITE_MUTEX_RECURSIVE. 3709** 3710** {F17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 3711** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 3712** returns a different mutex on every call. {F17034} But for the static 3713** mutex types, the same mutex is returned on every call that has 3714** the same type number. {END} 3715** 3716** {F17019} The sqlite3_mutex_free() routine deallocates a previously 3717** allocated dynamic mutex. {F17020} SQLite is careful to deallocate every 3718** dynamic mutex that it allocates. {U17021} The dynamic mutexes must not be in 3719** use when they are deallocated. {U17022} Attempting to deallocate a static 3720** mutex results in undefined behavior. {F17023} SQLite never deallocates 3721** a static mutex. {END} 3722** 3723** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 3724** to enter a mutex. {F17024} If another thread is already within the mutex, 3725** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 3726** SQLITE_BUSY. {F17025} The sqlite3_mutex_try() interface returns SQLITE_OK 3727** upon successful entry. {F17026} Mutexes created using 3728** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 3729** {F17027} In such cases the, 3730** mutex must be exited an equal number of times before another thread 3731** can enter. {U17028} If the same thread tries to enter any other 3732** kind of mutex more than once, the behavior is undefined. 3733** {F17029} SQLite will never exhibit 3734** such behavior in its own use of mutexes. {END} 3735** 3736** Some systems (ex: windows95) do not the operation implemented by 3737** sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() will 3738** always return SQLITE_BUSY. {F17030} The SQLite core only ever uses 3739** sqlite3_mutex_try() as an optimization so this is acceptable behavior. {END} 3740** 3741** {F17031} The sqlite3_mutex_leave() routine exits a mutex that was 3742** previously entered by the same thread. {U17032} The behavior 3743** is undefined if the mutex is not currently entered by the 3744** calling thread or is not currently allocated. {F17033} SQLite will 3745** never do either. {END} 3746** 3747** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 3748*/ 3749sqlite3_mutex *sqlite3_mutex_alloc(int); 3750void sqlite3_mutex_free(sqlite3_mutex*); 3751void sqlite3_mutex_enter(sqlite3_mutex*); 3752int sqlite3_mutex_try(sqlite3_mutex*); 3753void sqlite3_mutex_leave(sqlite3_mutex*); 3754 3755/* 3756** CAPI3REF: Mutex Verifcation Routines {F17080} 3757** 3758** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 3759** are intended for use inside assert() statements. {F17081} The SQLite core 3760** never uses these routines except inside an assert() and applications 3761** are advised to follow the lead of the core. {F17082} The core only 3762** provides implementations for these routines when it is compiled 3763** with the SQLITE_DEBUG flag. {U17087} External mutex implementations 3764** are only required to provide these routines if SQLITE_DEBUG is 3765** defined and if NDEBUG is not defined. 3766** 3767** {F17083} These routines should return true if the mutex in their argument 3768** is held or not held, respectively, by the calling thread. {END} 3769** 3770** {X17084} The implementation is not required to provided versions of these 3771** routines that actually work. 3772** If the implementation does not provide working 3773** versions of these routines, it should at least provide stubs 3774** that always return true so that one does not get spurious 3775** assertion failures. {END} 3776** 3777** {F17085} If the argument to sqlite3_mutex_held() is a NULL pointer then 3778** the routine should return 1. {END} This seems counter-intuitive since 3779** clearly the mutex cannot be held if it does not exist. But the 3780** the reason the mutex does not exist is because the build is not 3781** using mutexes. And we do not want the assert() containing the 3782** call to sqlite3_mutex_held() to fail, so a non-zero return is 3783** the appropriate thing to do. {F17086} The sqlite3_mutex_notheld() 3784** interface should also return 1 when given a NULL pointer. 3785*/ 3786int sqlite3_mutex_held(sqlite3_mutex*); 3787int sqlite3_mutex_notheld(sqlite3_mutex*); 3788 3789/* 3790** CAPI3REF: Mutex Types {F17001} 3791** 3792** {F17002} The [sqlite3_mutex_alloc()] interface takes a single argument 3793** which is one of these integer constants. {END} 3794*/ 3795#define SQLITE_MUTEX_FAST 0 3796#define SQLITE_MUTEX_RECURSIVE 1 3797#define SQLITE_MUTEX_STATIC_MASTER 2 3798#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 3799#define SQLITE_MUTEX_STATIC_MEM2 4 /* sqlite3_release_memory() */ 3800#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 3801#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 3802 3803/* 3804** CAPI3REF: Low-Level Control Of Database Files {F11300} 3805** 3806** {F11301} The [sqlite3_file_control()] interface makes a direct call to the 3807** xFileControl method for the [sqlite3_io_methods] object associated 3808** with a particular database identified by the second argument. {F11302} The 3809** name of the database is the name assigned to the database by the 3810** <a href="lang_attach.html">ATTACH</a> SQL command that opened the 3811** database. {F11303} To control the main database file, use the name "main" 3812** or a NULL pointer. {F11304} The third and fourth parameters to this routine 3813** are passed directly through to the second and third parameters of 3814** the xFileControl method. {F11305} The return value of the xFileControl 3815** method becomes the return value of this routine. 3816** 3817** {F11306} If the second parameter (zDbName) does not match the name of any 3818** open database file, then SQLITE_ERROR is returned. {F11307} This error 3819** code is not remembered and will not be recalled by [sqlite3_errcode()] 3820** or [sqlite3_errmsg()]. {U11308} The underlying xFileControl method might 3821** also return SQLITE_ERROR. {U11309} There is no way to distinguish between 3822** an incorrect zDbName and an SQLITE_ERROR return from the underlying 3823** xFileControl method. {END} 3824** 3825** See also: [SQLITE_FCNTL_LOCKSTATE] 3826*/ 3827int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 3828 3829/* 3830** Undo the hack that converts floating point types to integer for 3831** builds on processors without floating point support. 3832*/ 3833#ifdef SQLITE_OMIT_FLOATING_POINT 3834# undef double 3835#endif 3836 3837#ifdef __cplusplus 3838} /* End of the 'extern "C"' block */ 3839#endif 3840#endif 3841