1 /* 2 ** 2005 May 25 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 file contains the implementation of the sqlite3_prepare() 13 ** interface, and routines that contribute to loading the database schema 14 ** from disk. 15 ** 16 ** $Id: prepare.c,v 1.41 2006/11/09 00:24:54 drh Exp $ 17 */ 18 #include "sqliteInt.h" 19 #include "os.h" 20 #include <ctype.h> 21 22 /* 23 ** Fill the InitData structure with an error message that indicates 24 ** that the database is corrupt. 25 */ 26 static void corruptSchema(InitData *pData, const char *zExtra){ 27 if( !sqlite3MallocFailed() ){ 28 sqlite3SetString(pData->pzErrMsg, "malformed database schema", 29 zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0); 30 } 31 pData->rc = SQLITE_CORRUPT; 32 } 33 34 /* 35 ** This is the callback routine for the code that initializes the 36 ** database. See sqlite3Init() below for additional information. 37 ** This routine is also called from the OP_ParseSchema opcode of the VDBE. 38 ** 39 ** Each callback contains the following information: 40 ** 41 ** argv[0] = name of thing being created 42 ** argv[1] = root page number for table or index. 0 for trigger or view. 43 ** argv[2] = SQL text for the CREATE statement. 44 ** 45 */ 46 int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){ 47 InitData *pData = (InitData*)pInit; 48 sqlite3 *db = pData->db; 49 int iDb = pData->iDb; 50 51 pData->rc = SQLITE_OK; 52 DbClearProperty(db, iDb, DB_Empty); 53 if( sqlite3MallocFailed() ){ 54 corruptSchema(pData, 0); 55 return SQLITE_NOMEM; 56 } 57 58 assert( argc==3 ); 59 if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */ 60 if( argv[1]==0 ){ 61 corruptSchema(pData, 0); 62 return 1; 63 } 64 assert( iDb>=0 && iDb<db->nDb ); 65 if( argv[2] && argv[2][0] ){ 66 /* Call the parser to process a CREATE TABLE, INDEX or VIEW. 67 ** But because db->init.busy is set to 1, no VDBE code is generated 68 ** or executed. All the parser does is build the internal data 69 ** structures that describe the table, index, or view. 70 */ 71 char *zErr; 72 int rc; 73 assert( db->init.busy ); 74 db->init.iDb = iDb; 75 db->init.newTnum = atoi(argv[1]); 76 rc = sqlite3_exec(db, argv[2], 0, 0, &zErr); 77 db->init.iDb = 0; 78 assert( rc!=SQLITE_OK || zErr==0 ); 79 if( SQLITE_OK!=rc ){ 80 pData->rc = rc; 81 if( rc==SQLITE_NOMEM ){ 82 sqlite3FailedMalloc(); 83 }else if( rc!=SQLITE_INTERRUPT ){ 84 corruptSchema(pData, zErr); 85 } 86 sqlite3_free(zErr); 87 return 1; 88 } 89 }else{ 90 /* If the SQL column is blank it means this is an index that 91 ** was created to be the PRIMARY KEY or to fulfill a UNIQUE 92 ** constraint for a CREATE TABLE. The index should have already 93 ** been created when we processed the CREATE TABLE. All we have 94 ** to do here is record the root page number for that index. 95 */ 96 Index *pIndex; 97 pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName); 98 if( pIndex==0 || pIndex->tnum!=0 ){ 99 /* This can occur if there exists an index on a TEMP table which 100 ** has the same name as another index on a permanent index. Since 101 ** the permanent table is hidden by the TEMP table, we can also 102 ** safely ignore the index on the permanent table. 103 */ 104 /* Do Nothing */; 105 }else{ 106 pIndex->tnum = atoi(argv[1]); 107 } 108 } 109 return 0; 110 } 111 112 /* 113 ** Attempt to read the database schema and initialize internal 114 ** data structures for a single database file. The index of the 115 ** database file is given by iDb. iDb==0 is used for the main 116 ** database. iDb==1 should never be used. iDb>=2 is used for 117 ** auxiliary databases. Return one of the SQLITE_ error codes to 118 ** indicate success or failure. 119 */ 120 static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){ 121 int rc; 122 BtCursor *curMain; 123 int size; 124 Table *pTab; 125 Db *pDb; 126 char const *azArg[4]; 127 int meta[10]; 128 InitData initData; 129 char const *zMasterSchema; 130 char const *zMasterName = SCHEMA_TABLE(iDb); 131 132 /* 133 ** The master database table has a structure like this 134 */ 135 static const char master_schema[] = 136 "CREATE TABLE sqlite_master(\n" 137 " type text,\n" 138 " name text,\n" 139 " tbl_name text,\n" 140 " rootpage integer,\n" 141 " sql text\n" 142 ")" 143 ; 144 #ifndef SQLITE_OMIT_TEMPDB 145 static const char temp_master_schema[] = 146 "CREATE TEMP TABLE sqlite_temp_master(\n" 147 " type text,\n" 148 " name text,\n" 149 " tbl_name text,\n" 150 " rootpage integer,\n" 151 " sql text\n" 152 ")" 153 ; 154 #else 155 #define temp_master_schema 0 156 #endif 157 158 assert( iDb>=0 && iDb<db->nDb ); 159 assert( db->aDb[iDb].pSchema ); 160 161 /* zMasterSchema and zInitScript are set to point at the master schema 162 ** and initialisation script appropriate for the database being 163 ** initialised. zMasterName is the name of the master table. 164 */ 165 if( !OMIT_TEMPDB && iDb==1 ){ 166 zMasterSchema = temp_master_schema; 167 }else{ 168 zMasterSchema = master_schema; 169 } 170 zMasterName = SCHEMA_TABLE(iDb); 171 172 /* Construct the schema tables. */ 173 sqlite3SafetyOff(db); 174 azArg[0] = zMasterName; 175 azArg[1] = "1"; 176 azArg[2] = zMasterSchema; 177 azArg[3] = 0; 178 initData.db = db; 179 initData.iDb = iDb; 180 initData.pzErrMsg = pzErrMsg; 181 rc = sqlite3InitCallback(&initData, 3, (char **)azArg, 0); 182 if( rc ){ 183 sqlite3SafetyOn(db); 184 return initData.rc; 185 } 186 pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName); 187 if( pTab ){ 188 pTab->readOnly = 1; 189 } 190 sqlite3SafetyOn(db); 191 192 /* Create a cursor to hold the database open 193 */ 194 pDb = &db->aDb[iDb]; 195 if( pDb->pBt==0 ){ 196 if( !OMIT_TEMPDB && iDb==1 ){ 197 DbSetProperty(db, 1, DB_SchemaLoaded); 198 } 199 return SQLITE_OK; 200 } 201 rc = sqlite3BtreeCursor(pDb->pBt, MASTER_ROOT, 0, 0, 0, &curMain); 202 if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){ 203 sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0); 204 return rc; 205 } 206 207 /* Get the database meta information. 208 ** 209 ** Meta values are as follows: 210 ** meta[0] Schema cookie. Changes with each schema change. 211 ** meta[1] File format of schema layer. 212 ** meta[2] Size of the page cache. 213 ** meta[3] Use freelist if 0. Autovacuum if greater than zero. 214 ** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE 215 ** meta[5] The user cookie. Used by the application. 216 ** meta[6] 217 ** meta[7] 218 ** meta[8] 219 ** meta[9] 220 ** 221 ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to 222 ** the possible values of meta[4]. 223 */ 224 if( rc==SQLITE_OK ){ 225 int i; 226 for(i=0; rc==SQLITE_OK && i<sizeof(meta)/sizeof(meta[0]); i++){ 227 rc = sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]); 228 } 229 if( rc ){ 230 sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0); 231 sqlite3BtreeCloseCursor(curMain); 232 return rc; 233 } 234 }else{ 235 memset(meta, 0, sizeof(meta)); 236 } 237 pDb->pSchema->schema_cookie = meta[0]; 238 239 /* If opening a non-empty database, check the text encoding. For the 240 ** main database, set sqlite3.enc to the encoding of the main database. 241 ** For an attached db, it is an error if the encoding is not the same 242 ** as sqlite3.enc. 243 */ 244 if( meta[4] ){ /* text encoding */ 245 if( iDb==0 ){ 246 /* If opening the main database, set ENC(db). */ 247 ENC(db) = (u8)meta[4]; 248 db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0); 249 }else{ 250 /* If opening an attached database, the encoding much match ENC(db) */ 251 if( meta[4]!=ENC(db) ){ 252 sqlite3BtreeCloseCursor(curMain); 253 sqlite3SetString(pzErrMsg, "attached databases must use the same" 254 " text encoding as main database", (char*)0); 255 return SQLITE_ERROR; 256 } 257 } 258 }else{ 259 DbSetProperty(db, iDb, DB_Empty); 260 } 261 pDb->pSchema->enc = ENC(db); 262 263 size = meta[2]; 264 if( size==0 ){ size = MAX_PAGES; } 265 pDb->pSchema->cache_size = size; 266 sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); 267 268 /* 269 ** file_format==1 Version 3.0.0. 270 ** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN 271 ** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults 272 ** file_format==4 Version 3.3.0. // DESC indices. Boolean constants 273 */ 274 pDb->pSchema->file_format = meta[1]; 275 if( pDb->pSchema->file_format==0 ){ 276 pDb->pSchema->file_format = 1; 277 } 278 if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){ 279 sqlite3BtreeCloseCursor(curMain); 280 sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0); 281 return SQLITE_ERROR; 282 } 283 284 285 /* Read the schema information out of the schema tables 286 */ 287 assert( db->init.busy ); 288 if( rc==SQLITE_EMPTY ){ 289 /* For an empty database, there is nothing to read */ 290 rc = SQLITE_OK; 291 }else{ 292 char *zSql; 293 zSql = sqlite3MPrintf( 294 "SELECT name, rootpage, sql FROM '%q'.%s", 295 db->aDb[iDb].zName, zMasterName); 296 sqlite3SafetyOff(db); 297 rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0); 298 if( rc==SQLITE_ABORT ) rc = initData.rc; 299 sqlite3SafetyOn(db); 300 sqliteFree(zSql); 301 #ifndef SQLITE_OMIT_ANALYZE 302 if( rc==SQLITE_OK ){ 303 sqlite3AnalysisLoad(db, iDb); 304 } 305 #endif 306 sqlite3BtreeCloseCursor(curMain); 307 } 308 if( sqlite3MallocFailed() ){ 309 /* sqlite3SetString(pzErrMsg, "out of memory", (char*)0); */ 310 rc = SQLITE_NOMEM; 311 sqlite3ResetInternalSchema(db, 0); 312 } 313 if( rc==SQLITE_OK ){ 314 DbSetProperty(db, iDb, DB_SchemaLoaded); 315 }else{ 316 sqlite3ResetInternalSchema(db, iDb); 317 } 318 return rc; 319 } 320 321 /* 322 ** Initialize all database files - the main database file, the file 323 ** used to store temporary tables, and any additional database files 324 ** created using ATTACH statements. Return a success code. If an 325 ** error occurs, write an error message into *pzErrMsg. 326 ** 327 ** After a database is initialized, the DB_SchemaLoaded bit is set 328 ** bit is set in the flags field of the Db structure. If the database 329 ** file was of zero-length, then the DB_Empty flag is also set. 330 */ 331 int sqlite3Init(sqlite3 *db, char **pzErrMsg){ 332 int i, rc; 333 int called_initone = 0; 334 335 if( db->init.busy ) return SQLITE_OK; 336 rc = SQLITE_OK; 337 db->init.busy = 1; 338 for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 339 if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue; 340 rc = sqlite3InitOne(db, i, pzErrMsg); 341 if( rc ){ 342 sqlite3ResetInternalSchema(db, i); 343 } 344 called_initone = 1; 345 } 346 347 /* Once all the other databases have been initialised, load the schema 348 ** for the TEMP database. This is loaded last, as the TEMP database 349 ** schema may contain references to objects in other databases. 350 */ 351 #ifndef SQLITE_OMIT_TEMPDB 352 if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){ 353 rc = sqlite3InitOne(db, 1, pzErrMsg); 354 if( rc ){ 355 sqlite3ResetInternalSchema(db, 1); 356 } 357 called_initone = 1; 358 } 359 #endif 360 361 db->init.busy = 0; 362 if( rc==SQLITE_OK && called_initone ){ 363 sqlite3CommitInternalChanges(db); 364 } 365 366 return rc; 367 } 368 369 /* 370 ** This routine is a no-op if the database schema is already initialised. 371 ** Otherwise, the schema is loaded. An error code is returned. 372 */ 373 int sqlite3ReadSchema(Parse *pParse){ 374 int rc = SQLITE_OK; 375 sqlite3 *db = pParse->db; 376 if( !db->init.busy ){ 377 rc = sqlite3Init(db, &pParse->zErrMsg); 378 } 379 if( rc!=SQLITE_OK ){ 380 pParse->rc = rc; 381 pParse->nErr++; 382 } 383 return rc; 384 } 385 386 387 /* 388 ** Check schema cookies in all databases. If any cookie is out 389 ** of date, return 0. If all schema cookies are current, return 1. 390 */ 391 static int schemaIsValid(sqlite3 *db){ 392 int iDb; 393 int rc; 394 BtCursor *curTemp; 395 int cookie; 396 int allOk = 1; 397 398 for(iDb=0; allOk && iDb<db->nDb; iDb++){ 399 Btree *pBt; 400 pBt = db->aDb[iDb].pBt; 401 if( pBt==0 ) continue; 402 rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp); 403 if( rc==SQLITE_OK ){ 404 rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie); 405 if( rc==SQLITE_OK && cookie!=db->aDb[iDb].pSchema->schema_cookie ){ 406 allOk = 0; 407 } 408 sqlite3BtreeCloseCursor(curTemp); 409 } 410 } 411 return allOk; 412 } 413 414 /* 415 ** Convert a schema pointer into the iDb index that indicates 416 ** which database file in db->aDb[] the schema refers to. 417 ** 418 ** If the same database is attached more than once, the first 419 ** attached database is returned. 420 */ 421 int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){ 422 int i = -1000000; 423 424 /* If pSchema is NULL, then return -1000000. This happens when code in 425 ** expr.c is trying to resolve a reference to a transient table (i.e. one 426 ** created by a sub-select). In this case the return value of this 427 ** function should never be used. 428 ** 429 ** We return -1000000 instead of the more usual -1 simply because using 430 ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much 431 ** more likely to cause a segfault than -1 (of course there are assert() 432 ** statements too, but it never hurts to play the odds). 433 */ 434 if( pSchema ){ 435 for(i=0; i<db->nDb; i++){ 436 if( db->aDb[i].pSchema==pSchema ){ 437 break; 438 } 439 } 440 assert( i>=0 &&i>=0 && i<db->nDb ); 441 } 442 return i; 443 } 444 445 /* 446 ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. 447 */ 448 int sqlite3Prepare( 449 sqlite3 *db, /* Database handle. */ 450 const char *zSql, /* UTF-8 encoded SQL statement. */ 451 int nBytes, /* Length of zSql in bytes. */ 452 int saveSqlFlag, /* True to copy SQL text into the sqlite3_stmt */ 453 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 454 const char **pzTail /* OUT: End of parsed string */ 455 ){ 456 Parse sParse; 457 char *zErrMsg = 0; 458 int rc = SQLITE_OK; 459 int i; 460 461 /* Assert that malloc() has not failed */ 462 assert( !sqlite3MallocFailed() ); 463 464 assert( ppStmt ); 465 *ppStmt = 0; 466 if( sqlite3SafetyOn(db) ){ 467 return SQLITE_MISUSE; 468 } 469 470 /* If any attached database schemas are locked, do not proceed with 471 ** compilation. Instead return SQLITE_LOCKED immediately. 472 */ 473 for(i=0; i<db->nDb; i++) { 474 Btree *pBt = db->aDb[i].pBt; 475 if( pBt && sqlite3BtreeSchemaLocked(pBt) ){ 476 const char *zDb = db->aDb[i].zName; 477 sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb); 478 sqlite3SafetyOff(db); 479 return SQLITE_LOCKED; 480 } 481 } 482 483 memset(&sParse, 0, sizeof(sParse)); 484 sParse.db = db; 485 if( nBytes>=0 && zSql[nBytes]!=0 ){ 486 char *zSqlCopy = sqlite3StrNDup(zSql, nBytes); 487 sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg); 488 sParse.zTail += zSql - zSqlCopy; 489 sqliteFree(zSqlCopy); 490 }else{ 491 sqlite3RunParser(&sParse, zSql, &zErrMsg); 492 } 493 494 if( sqlite3MallocFailed() ){ 495 sParse.rc = SQLITE_NOMEM; 496 } 497 if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK; 498 if( sParse.checkSchema && !schemaIsValid(db) ){ 499 sParse.rc = SQLITE_SCHEMA; 500 } 501 if( sParse.rc==SQLITE_SCHEMA ){ 502 sqlite3ResetInternalSchema(db, 0); 503 } 504 if( sqlite3MallocFailed() ){ 505 sParse.rc = SQLITE_NOMEM; 506 } 507 if( pzTail ){ 508 *pzTail = sParse.zTail; 509 } 510 rc = sParse.rc; 511 512 #ifndef SQLITE_OMIT_EXPLAIN 513 if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){ 514 if( sParse.explain==2 ){ 515 sqlite3VdbeSetNumCols(sParse.pVdbe, 3); 516 sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC); 517 sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC); 518 sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC); 519 }else{ 520 sqlite3VdbeSetNumCols(sParse.pVdbe, 5); 521 sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC); 522 sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC); 523 sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC); 524 sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC); 525 sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC); 526 } 527 } 528 #endif 529 530 if( sqlite3SafetyOff(db) ){ 531 rc = SQLITE_MISUSE; 532 } 533 if( rc==SQLITE_OK ){ 534 if( saveSqlFlag ){ 535 sqlite3VdbeSetSql(sParse.pVdbe, zSql, sParse.zTail - zSql); 536 } 537 *ppStmt = (sqlite3_stmt*)sParse.pVdbe; 538 }else if( sParse.pVdbe ){ 539 sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe); 540 } 541 542 if( zErrMsg ){ 543 sqlite3Error(db, rc, "%s", zErrMsg); 544 sqliteFree(zErrMsg); 545 }else{ 546 sqlite3Error(db, rc, 0); 547 } 548 549 rc = sqlite3ApiExit(db, rc); 550 sqlite3ReleaseThreadData(); 551 assert( (rc&db->errMask)==rc ); 552 return rc; 553 } 554 555 /* 556 ** Rerun the compilation of a statement after a schema change. 557 ** Return true if the statement was recompiled successfully. 558 ** Return false if there is an error of some kind. 559 */ 560 int sqlite3Reprepare(Vdbe *p){ 561 int rc; 562 Vdbe *pNew; 563 const char *zSql; 564 sqlite3 *db; 565 566 zSql = sqlite3VdbeGetSql(p); 567 if( zSql==0 ){ 568 return 0; 569 } 570 db = sqlite3VdbeDb(p); 571 rc = sqlite3Prepare(db, zSql, -1, 0, (sqlite3_stmt**)&pNew, 0); 572 if( rc ){ 573 assert( pNew==0 ); 574 return 0; 575 }else{ 576 assert( pNew!=0 ); 577 } 578 sqlite3VdbeSwapOps(pNew, p); 579 sqlite3_finalize((sqlite3_stmt*)pNew); 580 return 1; 581 } 582 583 584 /* 585 ** Two versions of the official API. Legacy and new use. In the legacy 586 ** version, the original SQL text is not saved in the prepared statement 587 ** and so if a schema change occurs, SQLITE_SCHEMA is returned by 588 ** sqlite3_step(). In the new version, the original SQL text is retained 589 ** and the statement is automatically recompiled if an schema change 590 ** occurs. 591 */ 592 int sqlite3_prepare( 593 sqlite3 *db, /* Database handle. */ 594 const char *zSql, /* UTF-8 encoded SQL statement. */ 595 int nBytes, /* Length of zSql in bytes. */ 596 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 597 const char **pzTail /* OUT: End of parsed string */ 598 ){ 599 return sqlite3Prepare(db,zSql,nBytes,0,ppStmt,pzTail); 600 } 601 int sqlite3_prepare_v2( 602 sqlite3 *db, /* Database handle. */ 603 const char *zSql, /* UTF-8 encoded SQL statement. */ 604 int nBytes, /* Length of zSql in bytes. */ 605 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 606 const char **pzTail /* OUT: End of parsed string */ 607 ){ 608 return sqlite3Prepare(db,zSql,nBytes,1,ppStmt,pzTail); 609 } 610 611 612 #ifndef SQLITE_OMIT_UTF16 613 /* 614 ** Compile the UTF-16 encoded SQL statement zSql into a statement handle. 615 */ 616 static int sqlite3Prepare16( 617 sqlite3 *db, /* Database handle. */ 618 const void *zSql, /* UTF-8 encoded SQL statement. */ 619 int nBytes, /* Length of zSql in bytes. */ 620 int saveSqlFlag, /* True to save SQL text into the sqlite3_stmt */ 621 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 622 const void **pzTail /* OUT: End of parsed string */ 623 ){ 624 /* This function currently works by first transforming the UTF-16 625 ** encoded string to UTF-8, then invoking sqlite3_prepare(). The 626 ** tricky bit is figuring out the pointer to return in *pzTail. 627 */ 628 char *zSql8; 629 const char *zTail8 = 0; 630 int rc = SQLITE_OK; 631 632 if( sqlite3SafetyCheck(db) ){ 633 return SQLITE_MISUSE; 634 } 635 zSql8 = sqlite3utf16to8(zSql, nBytes); 636 if( zSql8 ){ 637 rc = sqlite3Prepare(db, zSql8, -1, saveSqlFlag, ppStmt, &zTail8); 638 } 639 640 if( zTail8 && pzTail ){ 641 /* If sqlite3_prepare returns a tail pointer, we calculate the 642 ** equivalent pointer into the UTF-16 string by counting the unicode 643 ** characters between zSql8 and zTail8, and then returning a pointer 644 ** the same number of characters into the UTF-16 string. 645 */ 646 int chars_parsed = sqlite3utf8CharLen(zSql8, zTail8-zSql8); 647 *pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed); 648 } 649 sqliteFree(zSql8); 650 return sqlite3ApiExit(db, rc); 651 } 652 653 /* 654 ** Two versions of the official API. Legacy and new use. In the legacy 655 ** version, the original SQL text is not saved in the prepared statement 656 ** and so if a schema change occurs, SQLITE_SCHEMA is returned by 657 ** sqlite3_step(). In the new version, the original SQL text is retained 658 ** and the statement is automatically recompiled if an schema change 659 ** occurs. 660 */ 661 int sqlite3_prepare16( 662 sqlite3 *db, /* Database handle. */ 663 const void *zSql, /* UTF-8 encoded SQL statement. */ 664 int nBytes, /* Length of zSql in bytes. */ 665 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 666 const void **pzTail /* OUT: End of parsed string */ 667 ){ 668 return sqlite3Prepare16(db,zSql,nBytes,0,ppStmt,pzTail); 669 } 670 int sqlite3_prepare16_v2( 671 sqlite3 *db, /* Database handle. */ 672 const void *zSql, /* UTF-8 encoded SQL statement. */ 673 int nBytes, /* Length of zSql in bytes. */ 674 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ 675 const void **pzTail /* OUT: End of parsed string */ 676 ){ 677 return sqlite3Prepare16(db,zSql,nBytes,1,ppStmt,pzTail); 678 } 679 680 #endif /* SQLITE_OMIT_UTF16 */ 681