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);#ifndef SQLITE_OMIT_ANALYZE    if( rc==SQLITE_OK ){      sqlite3AnalysisLoad(db, iDb);    }#endif    sqlite3BtreeCloseCursor(curMain);  }  if( sqlite3MallocFailed() ){    /* 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 a database is initialized, the DB_SchemaLoaded bit is set** bit is set in the flags field of the Db structure. If the database** file was of zero-length, then the DB_Empty flag is also set.*/int sqlite3Init(sqlite3 *db, char **pzErrMsg){  int i, rc;  int called_initone = 0;    if( db->init.busy ) return SQLITE_OK;  rc = SQLITE_OK;  db->init.busy = 1;  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;    rc = sqlite3InitOne(db, i, pzErrMsg);    if( rc ){      sqlite3ResetInternalSchema(db, i);    }    called_initone = 1;  }  /* 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);    }    called_initone = 1;  }#endif  db->init.busy = 0;  if( rc==SQLITE_OK && called_initone ){    sqlite3CommitInternalChanges(db);  }  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 ){    rc = sqlite3Init(db, &pParse->zErrMsg);  }  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 && iDb<db->nDb; 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].pSchema->schema_cookie ){        allOk = 0;      }      sqlite3BtreeCloseCursor(curTemp);    }  }  return allOk;}/*** Convert a schema pointer into the iDb index that indicates** which database file in db->aDb[] the schema refers to.**** If the same database is attached more than once, the first** attached database is returned.*/int sqlite3SchemaToIndex(sqlite3 *db, Schema *pSchema){  int i = -1000000;  /* If pSchema is NULL, then return -1000000. This happens when code in   ** expr.c is trying to resolve a reference to a transient table (i.e. one  ** created by a sub-select). In this case the return value of this   ** function should never be used.  **  ** We return -1000000 instead of the more usual -1 simply because using  ** -1000000 as incorrectly using -1000000 index into db->aDb[] is much   ** more likely to cause a segfault than -1 (of course there are assert()  ** statements too, but it never hurts to play the odds).  */  if( pSchema ){    for(i=0; i<db->nDb; i++){      if( db->aDb[i].pSchema==pSchema ){        break;      }    }    assert( i>=0 &&i>=0 &&  i<db->nDb );  }  return i;}/*** 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;  int i;  /* Assert that malloc() has not failed */  assert( !sqlite3MallocFailed() );  assert( ppStmt );  *ppStmt = 0;  if( sqlite3SafetyOn(db) ){    return SQLITE_MISUSE;  }  /* If any attached database schemas are locked, do not proceed with  ** compilation. Instead return SQLITE_LOCKED immediately.  */  for(i=0; i<db->nDb; i++) {    Btree *pBt = db->aDb[i].pBt;    if( pBt && sqlite3BtreeSchemaLocked(pBt) ){      const char *zDb = db->aDb[i].zName;      sqlite3Error(db, SQLITE_LOCKED, "database schema is locked: %s", zDb);      sqlite3SafetyOff(db);      return SQLITE_LOCKED;    }  }    memset(&sParse, 0, sizeof(sParse));  sParse.db = db;  if( nBytes>=0 && zSql[nBytes]!=0 ){    char *zSqlCopy = sqlite3StrNDup(zSql, nBytes);    sqlite3RunParser(&sParse, zSqlCopy, &zErrMsg);    sParse.zTail += zSql - zSqlCopy;    sqliteFree(zSqlCopy);  }else{    sqlite3RunParser(&sParse, zSql, &zErrMsg);  }  if( sqlite3MallocFailed() ){    sParse.rc = SQLITE_NOMEM;  }  if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;  if( 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 ){    if( sParse.explain==2 ){      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC);    }else{      sqlite3VdbeSetNumCols(sParse.pVdbe, 5);      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC);      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC);    }  } #endif  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);  }  rc = sqlite3ApiExit(db, rc);  sqlite3ReleaseThreadData();  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 *zSql8;  const char *zTail8 = 0;  int rc = SQLITE_OK;  if( sqlite3SafetyCheck(db) ){    return SQLITE_MISUSE;  }  zSql8 = sqlite3utf16to8(zSql, nBytes);  if( zSql8 ){    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);  }  sqliteFree(zSql8);   return sqlite3ApiExit(db, rc);}#endif /* SQLITE_OMIT_UTF16 */