/* ** 2005 May 25 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the implementation of the sqlite3_prepare() ** interface, and routines that contribute to loading the database schema ** from disk. ** ** $Id: prepare.c,v 1.1.1.1 2006/02/03 20:35:11 hoganrobert Exp $ */ #include "sqliteInt.h" #include "os.h" #include /* ** Fill the InitData structure with an error message that indicates ** that the database is corrupt. */ static void corruptSchema(InitData *pData, const char *zExtra){ if( !sqlite3_malloc_failed ){ sqlite3SetString(pData->pzErrMsg, "malformed database schema", zExtra!=0 && zExtra[0]!=0 ? " - " : (char*)0, zExtra, (char*)0); } } /* ** This is the callback routine for the code that initializes the ** database. See sqlite3Init() below for additional information. ** This routine is also called from the OP_ParseSchema opcode of the VDBE. ** ** Each callback contains the following information: ** ** argv[0] = name of thing being created ** argv[1] = root page number for table or index. NULL for trigger or view. ** argv[2] = SQL text for the CREATE statement. ** argv[3] = "1" for temporary files, "0" for main database, "2" or more ** for auxiliary database files. ** */ int sqlite3InitCallback(void *pInit, int argc, char **argv, char **azColName){ InitData *pData = (InitData*)pInit; sqlite3 *db = pData->db; int iDb; assert( argc==4 ); if( argv==0 ) return 0; /* Might happen if EMPTY_RESULT_CALLBACKS are on */ if( argv[1]==0 || argv[3]==0 ){ corruptSchema(pData, 0); return 1; } iDb = atoi(argv[3]); assert( iDb>=0 && iDbnDb ); if( argv[2] && argv[2][0] ){ /* Call the parser to process a CREATE TABLE, INDEX or VIEW. ** But because db->init.busy is set to 1, no VDBE code is generated ** or executed. All the parser does is build the internal data ** structures that describe the table, index, or view. */ char *zErr; int rc; assert( db->init.busy ); db->init.iDb = iDb; db->init.newTnum = atoi(argv[1]); rc = sqlite3_exec(db, argv[2], 0, 0, &zErr); db->init.iDb = 0; if( SQLITE_OK!=rc ){ corruptSchema(pData, zErr); sqlite3_free(zErr); return rc; } }else{ /* If the SQL column is blank it means this is an index that ** was created to be the PRIMARY KEY or to fulfill a UNIQUE ** constraint for a CREATE TABLE. The index should have already ** been created when we processed the CREATE TABLE. All we have ** to do here is record the root page number for that index. */ Index *pIndex; pIndex = sqlite3FindIndex(db, argv[0], db->aDb[iDb].zName); if( pIndex==0 || pIndex->tnum!=0 ){ /* This can occur if there exists an index on a TEMP table which ** has the same name as another index on a permanent index. Since ** the permanent table is hidden by the TEMP table, we can also ** safely ignore the index on the permanent table. */ /* Do Nothing */; }else{ pIndex->tnum = atoi(argv[1]); } } return 0; } /* ** Attempt to read the database schema and initialize internal ** data structures for a single database file. The index of the ** database file is given by iDb. iDb==0 is used for the main ** database. iDb==1 should never be used. iDb>=2 is used for ** auxiliary databases. Return one of the SQLITE_ error codes to ** indicate success or failure. */ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){ int rc; BtCursor *curMain; int size; Table *pTab; char const *azArg[5]; char zDbNum[30]; int meta[10]; InitData initData; char const *zMasterSchema; char const *zMasterName = SCHEMA_TABLE(iDb); /* ** The master database table has a structure like this */ static const char master_schema[] = "CREATE TABLE sqlite_master(\n" " type text,\n" " name text,\n" " tbl_name text,\n" " rootpage integer,\n" " sql text\n" ")" ; #ifndef SQLITE_OMIT_TEMPDB static const char temp_master_schema[] = "CREATE TEMP TABLE sqlite_temp_master(\n" " type text,\n" " name text,\n" " tbl_name text,\n" " rootpage integer,\n" " sql text\n" ")" ; #else #define temp_master_schema 0 #endif assert( iDb>=0 && iDbnDb ); /* zMasterSchema and zInitScript are set to point at the master schema ** and initialisation script appropriate for the database being ** initialised. zMasterName is the name of the master table. */ if( !OMIT_TEMPDB && iDb==1 ){ zMasterSchema = temp_master_schema; }else{ zMasterSchema = master_schema; } zMasterName = SCHEMA_TABLE(iDb); /* Construct the schema tables. */ sqlite3SafetyOff(db); azArg[0] = zMasterName; azArg[1] = "1"; azArg[2] = zMasterSchema; sprintf(zDbNum, "%d", iDb); azArg[3] = zDbNum; azArg[4] = 0; initData.db = db; initData.pzErrMsg = pzErrMsg; rc = sqlite3InitCallback(&initData, 4, (char **)azArg, 0); if( rc!=SQLITE_OK ){ sqlite3SafetyOn(db); return rc; } pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName); if( pTab ){ pTab->readOnly = 1; } sqlite3SafetyOn(db); /* Create a cursor to hold the database open */ if( db->aDb[iDb].pBt==0 ){ if( !OMIT_TEMPDB && iDb==1 ) DbSetProperty(db, 1, DB_SchemaLoaded); return SQLITE_OK; } rc = sqlite3BtreeCursor(db->aDb[iDb].pBt, MASTER_ROOT, 0, 0, 0, &curMain); if( rc!=SQLITE_OK && rc!=SQLITE_EMPTY ){ sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0); return rc; } /* Get the database meta information. ** ** Meta values are as follows: ** meta[0] Schema cookie. Changes with each schema change. ** meta[1] File format of schema layer. ** meta[2] Size of the page cache. ** meta[3] Use freelist if 0. Autovacuum if greater than zero. ** meta[4] Db text encoding. 1:UTF-8 3:UTF-16 LE 4:UTF-16 BE ** meta[5] The user cookie. Used by the application. ** meta[6] ** meta[7] ** meta[8] ** meta[9] ** ** Note: The hash defined SQLITE_UTF* symbols in sqliteInt.h correspond to ** the possible values of meta[4]. */ if( rc==SQLITE_OK ){ int i; for(i=0; rc==SQLITE_OK && iaDb[iDb].pBt, i+1, (u32 *)&meta[i]); } if( rc ){ sqlite3SetString(pzErrMsg, sqlite3ErrStr(rc), (char*)0); sqlite3BtreeCloseCursor(curMain); return rc; } }else{ memset(meta, 0, sizeof(meta)); } db->aDb[iDb].schema_cookie = meta[0]; /* If opening a non-empty database, check the text encoding. For the ** main database, set sqlite3.enc to the encoding of the main database. ** For an attached db, it is an error if the encoding is not the same ** as sqlite3.enc. */ if( meta[4] ){ /* text encoding */ if( iDb==0 ){ /* If opening the main database, set db->enc. */ db->enc = (u8)meta[4]; db->pDfltColl = sqlite3FindCollSeq(db, db->enc, "BINARY", 6, 0); }else{ /* If opening an attached database, the encoding much match db->enc */ if( meta[4]!=db->enc ){ sqlite3BtreeCloseCursor(curMain); sqlite3SetString(pzErrMsg, "attached databases must use the same" " text encoding as main database", (char*)0); return SQLITE_ERROR; } } } size = meta[2]; if( size==0 ){ size = MAX_PAGES; } db->aDb[iDb].cache_size = size; if( iDb==0 ){ db->file_format = meta[1]; if( db->file_format==0 ){ /* This happens if the database was initially empty */ db->file_format = 1; } if( db->file_format==2 || db->file_format==3 ){ /* File format 2 is treated exactly as file format 1. New ** databases are created with file format 1. */ db->file_format = 1; } } /* ** file_format==1 Version 3.0.0. ** file_format==2 Version 3.1.3. ** file_format==3 Version 3.1.4. ** ** Version 3.0 can only use files with file_format==1. Version 3.1.3 ** can read and write files with file_format==1 or file_format==2. ** Version 3.1.4 can read and write file formats 1, 2 and 3. */ if( meta[1]>3 ){ sqlite3BtreeCloseCursor(curMain); sqlite3SetString(pzErrMsg, "unsupported file format", (char*)0); return SQLITE_ERROR; } sqlite3BtreeSetCacheSize(db->aDb[iDb].pBt, db->aDb[iDb].cache_size); /* Read the schema information out of the schema tables */ assert( db->init.busy ); if( rc==SQLITE_EMPTY ){ /* For an empty database, there is nothing to read */ rc = SQLITE_OK; }else{ char *zSql; zSql = sqlite3MPrintf( "SELECT name, rootpage, sql, '%s' FROM '%q'.%s", zDbNum, db->aDb[iDb].zName, zMasterName); sqlite3SafetyOff(db); rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0); sqlite3SafetyOn(db); sqliteFree(zSql); sqlite3BtreeCloseCursor(curMain); } if( sqlite3_malloc_failed ){ sqlite3SetString(pzErrMsg, "out of memory", (char*)0); rc = SQLITE_NOMEM; sqlite3ResetInternalSchema(db, 0); } if( rc==SQLITE_OK ){ DbSetProperty(db, iDb, DB_SchemaLoaded); }else{ sqlite3ResetInternalSchema(db, iDb); } return rc; } /* ** Initialize all database files - the main database file, the file ** used to store temporary tables, and any additional database files ** created using ATTACH statements. Return a success code. If an ** error occurs, write an error message into *pzErrMsg. ** ** After the database is initialized, the SQLITE_Initialized ** bit is set in the flags field of the sqlite structure. */ int sqlite3Init(sqlite3 *db, char **pzErrMsg){ int i, rc; if( db->init.busy ) return SQLITE_OK; assert( (db->flags & SQLITE_Initialized)==0 ); rc = SQLITE_OK; db->init.busy = 1; for(i=0; rc==SQLITE_OK && inDb; i++){ if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue; rc = sqlite3InitOne(db, i, pzErrMsg); if( rc ){ sqlite3ResetInternalSchema(db, i); } } /* Once all the other databases have been initialised, load the schema ** for the TEMP database. This is loaded last, as the TEMP database ** schema may contain references to objects in other databases. */ #ifndef SQLITE_OMIT_TEMPDB if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){ rc = sqlite3InitOne(db, 1, pzErrMsg); if( rc ){ sqlite3ResetInternalSchema(db, 1); } } #endif db->init.busy = 0; if( rc==SQLITE_OK ){ db->flags |= SQLITE_Initialized; sqlite3CommitInternalChanges(db); } if( rc!=SQLITE_OK ){ db->flags &= ~SQLITE_Initialized; } return rc; } /* ** This routine is a no-op if the database schema is already initialised. ** Otherwise, the schema is loaded. An error code is returned. */ int sqlite3ReadSchema(Parse *pParse){ int rc = SQLITE_OK; sqlite3 *db = pParse->db; if( !db->init.busy ){ if( (db->flags & SQLITE_Initialized)==0 ){ rc = sqlite3Init(db, &pParse->zErrMsg); } } assert( rc!=SQLITE_OK || (db->flags & SQLITE_Initialized)||db->init.busy ); if( rc!=SQLITE_OK ){ pParse->rc = rc; pParse->nErr++; } return rc; } /* ** Check schema cookies in all databases. If any cookie is out ** of date, return 0. If all schema cookies are current, return 1. */ static int schemaIsValid(sqlite3 *db){ int iDb; int rc; BtCursor *curTemp; int cookie; int allOk = 1; for(iDb=0; allOk && iDbnDb; iDb++){ Btree *pBt; pBt = db->aDb[iDb].pBt; if( pBt==0 ) continue; rc = sqlite3BtreeCursor(pBt, MASTER_ROOT, 0, 0, 0, &curTemp); if( rc==SQLITE_OK ){ rc = sqlite3BtreeGetMeta(pBt, 1, (u32 *)&cookie); if( rc==SQLITE_OK && cookie!=db->aDb[iDb].schema_cookie ){ allOk = 0; } sqlite3BtreeCloseCursor(curTemp); } } return allOk; } /* ** Compile the UTF-8 encoded SQL statement zSql into a statement handle. */ int sqlite3_prepare( sqlite3 *db, /* Database handle. */ const char *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const char** pzTail /* OUT: End of parsed string */ ){ Parse sParse; char *zErrMsg = 0; int rc = SQLITE_OK; if( sqlite3_malloc_failed ){ return SQLITE_NOMEM; } assert( ppStmt ); *ppStmt = 0; if( sqlite3SafetyOn(db) ){ return SQLITE_MISUSE; } memset(&sParse, 0, sizeof(sParse)); sParse.db = db; sqlite3RunParser(&sParse, zSql, &zErrMsg); if( sqlite3_malloc_failed ){ rc = SQLITE_NOMEM; sqlite3RollbackAll(db); sqlite3ResetInternalSchema(db, 0); db->flags &= ~SQLITE_InTrans; goto prepare_out; } if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK; if( sParse.rc!=SQLITE_OK && sParse.checkSchema && !schemaIsValid(db) ){ sParse.rc = SQLITE_SCHEMA; } if( sParse.rc==SQLITE_SCHEMA ){ sqlite3ResetInternalSchema(db, 0); } if( pzTail ) *pzTail = sParse.zTail; rc = sParse.rc; #ifndef SQLITE_OMIT_EXPLAIN if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){ sqlite3VdbeSetNumCols(sParse.pVdbe, 5); sqlite3VdbeSetColName(sParse.pVdbe, 0, "addr", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 1, "opcode", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 2, "p1", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 3, "p2", P3_STATIC); sqlite3VdbeSetColName(sParse.pVdbe, 4, "p3", P3_STATIC); } #endif prepare_out: if( sqlite3SafetyOff(db) ){ rc = SQLITE_MISUSE; } if( rc==SQLITE_OK ){ *ppStmt = (sqlite3_stmt*)sParse.pVdbe; }else if( sParse.pVdbe ){ sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe); } if( zErrMsg ){ sqlite3Error(db, rc, "%s", zErrMsg); sqliteFree(zErrMsg); }else{ sqlite3Error(db, rc, 0); } return rc; } #ifndef SQLITE_OMIT_UTF16 /* ** Compile the UTF-16 encoded SQL statement zSql into a statement handle. */ int sqlite3_prepare16( sqlite3 *db, /* Database handle. */ const void *zSql, /* UTF-8 encoded SQL statement. */ int nBytes, /* Length of zSql in bytes. */ sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ const void **pzTail /* OUT: End of parsed string */ ){ /* This function currently works by first transforming the UTF-16 ** encoded string to UTF-8, then invoking sqlite3_prepare(). The ** tricky bit is figuring out the pointer to return in *pzTail. */ char const *zSql8 = 0; char const *zTail8 = 0; int rc; sqlite3_value *pTmp; if( sqlite3SafetyCheck(db) ){ return SQLITE_MISUSE; } pTmp = sqlite3GetTransientValue(db); sqlite3ValueSetStr(pTmp, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC); zSql8 = sqlite3ValueText(pTmp, SQLITE_UTF8); if( !zSql8 ){ sqlite3Error(db, SQLITE_NOMEM, 0); return SQLITE_NOMEM; } rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8); if( zTail8 && pzTail ){ /* If sqlite3_prepare returns a tail pointer, we calculate the ** equivalent pointer into the UTF-16 string by counting the unicode ** characters between zSql8 and zTail8, and then returning a pointer ** the same number of characters into the UTF-16 string. */ int chars_parsed = sqlite3utf8CharLen(zSql8, zTail8-zSql8); *pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed); } return rc; } #endif /* SQLITE_OMIT_UTF16 */