SQLite

**    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 1.122 2009/06/16 17:49:36 drh Exp $
*/
#include "sqliteInt.h"

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/
static void corruptSchema(
  InitData *pData,     /* Initialization context */
  const char *zObj,    /* Object being parsed at the point of error */
  const char *zExtra   /* Error information */
){
  sqlite3 *db = pData->db;
  if( !db->mallocFailed && (db->flags & SQLITE_RecoveryMode)==0 ){
    if( zObj==0 ) zObj = "?";
    sqlite3SetString(pData->pzErrMsg, pData->db,
       "malformed database schema (%s)", zObj);
    if( zExtra ){
      *pData->pzErrMsg = sqlite3MAppendf(pData->db, *pData->pzErrMsg, "%s - %s",
                                  *pData->pzErrMsg, zExtra);
    }
  }
  pData->rc = db->mallocFailed ? SQLITE_NOMEM : SQLITE_CORRUPT;
}

/*
** 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.
**

  assert( argc==3 );
  UNUSED_PARAMETER2(NotUsed, argc);
  assert( sqlite3_mutex_held(db->mutex) );
  DbClearProperty(db, iDb, DB_Empty);
  if( db->mallocFailed ){
    corruptSchema(pData, argv[0], 0);
    return 1;
  }

  assert( iDb>=0 && iDb<db->nDb );
  if( argv==0 ) return 0;   /* Might happen if EMPTY_RESULT_CALLBACKS are on */
  if( argv[1]==0 ){
    corruptSchema(pData, argv[0], 0);
  }else if( argv[2] && argv[2][0] ){

    rc = sqlite3_exec(db, argv[2], 0, 0, &zErr);
    db->init.iDb = 0;
    assert( rc!=SQLITE_OK || zErr==0 );
    if( SQLITE_OK!=rc ){
      pData->rc = rc;
      if( rc==SQLITE_NOMEM ){
        db->mallocFailed = 1;
      }else if( rc!=SQLITE_INTERRUPT ){
        corruptSchema(pData, argv[0], zErr);
      }
      sqlite3DbFree(db, zErr);
    }
  }else if( argv[0]==0 ){
    corruptSchema(pData, 0, 0);
  }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 ){
      /* 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 if( sqlite3GetInt32(argv[1], &pIndex->tnum)==0 ){
      corruptSchema(pData, argv[0], "invalid rootpage");
    }
  }
  return 0;
}

/*
** Attempt to read the database schema and initialize internal

  sqlite3InitCallback(&initData, 3, (char **)azArg, 0);
  (void)sqlite3SafetyOn(db);
  if( initData.rc ){
    rc = initData.rc;
    goto error_out;
  }
  pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName);
  if( ALWAYS(pTab) ){
    pTab->tabFlags |= TF_Readonly;
  }

  /* Create a cursor to hold the database open
  */
  pDb = &db->aDb[iDb];
  if( pDb->pBt==0 ){
    if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){
      DbSetProperty(db, 1, DB_SchemaLoaded);
    }
    return SQLITE_OK;
  }
  curMain = sqlite3MallocZero(sqlite3BtreeCursorSize());
  if( !curMain ){
    rc = SQLITE_NOMEM;

  if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){
    db->flags &= ~SQLITE_LegacyFileFmt;
  }

  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );




  {
    char *zSql;
    zSql = sqlite3MPrintf(db, 
        "SELECT name, rootpage, sql FROM '%q'.%s",
        db->aDb[iDb].zName, zMasterName);
    (void)sqlite3SafetyOff(db);
#ifndef SQLITE_OMIT_AUTHORIZATION
    {

** file was of zero-length, then the DB_Empty flag is also set.
*/
int sqlite3Init(sqlite3 *db, char **pzErrMsg){
  int i, rc;
  int commit_internal = !(db->flags&SQLITE_InternChanges);
  
  assert( sqlite3_mutex_held(db->mutex) );

  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);
    }
  }

  /* 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 && ALWAYS(db->nDb>1)
                    && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
    rc = sqlite3InitOne(db, 1, pzErrMsg);
    if( rc ){
      sqlite3ResetInternalSchema(db, 1);
    }
  }
#endif

  *ppStmt = 0;
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE;
  }
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
  if( rc==SQLITE_SCHEMA ){
    sqlite3_finalize(*ppStmt);
    rc = sqlite3Prepare(db, zSql, nBytes, saveSqlFlag, ppStmt, pzTail);
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Rerun the compilation of a statement after a schema change.

# 2001 September 15
#
# 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 implements regression tests for SQLite library.  The
# focus of this script is database locks.
#
# $Id: lock.test,v 1.40 2009/06/16 17:49:36 drh Exp $


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Create an alternative connection to the database
#

do_test lock-1.13 {
  execsql {CREATE TABLE t2(x int, y int)}
  execsql {INSERT INTO t2 VALUES(8,9)}
  execsql {SELECT * FROM t2}
} {8 9}
do_test lock-1.14.1 {
  catchsql {SELECT * FROM t2} db2
} {0 {8 9}}
do_test lock-1.14.2 {
  catchsql {SELECT * FROM t1} db2
} {0 {2 1}}
do_test lock-1.15 {
  catchsql {SELECT * FROM t2} db2
} {0 {8 9}}

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for temporary tables and indices.
#
# $Id: temptable.test,v 1.21 2009/06/16 17:49:36 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

ifcapable !tempdb {
  finish_test
  return

    SELECT * FROM temp.t2;
  } db2
} {0 {10 20}}
do_test temptable-4.4.2 {
  catchsql {
    SELECT * FROM main.t2;
  } db2
} {0 {9 8 7}}
#do_test temptable-4.4.3 {
#  catchsql {
#    SELECT name FROM main.sqlite_master WHERE type='table';
#  } db2
#} {1 {database schema has changed}}
do_test temptable-4.4.4 {
  catchsql {