SQLite

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.258 2004/02/10 13:41:52 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

  assert( pTos->flags==MEM_Int );
  pTos--;
  break;
}

/* Opcode: ListRewind * * *
**
** Rewind the temporary buffer back to the beginning.

*/
case OP_ListRewind: {
  /* What this opcode codes, really, is reverse the order of the
  ** linked list of Keylist structures so that they are read out
  ** in the same order that they were read in. */
  Keylist *pRev, *pTop;
  pRev = 0;
  while( p->pList ){
    pTop = p->pList;
    p->pList = pTop->pNext;
    pTop->pNext = pRev;
    pRev = pTop;
  }
  p->pList = pRev;
  break;
}

/* Opcode: ListRead * P2 *
**
** Attempt to read an integer from the temporary storage buffer
** and push it onto the stack.  If the storage buffer is empty, 

# 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 file is testing the UPDATE statement.
#
# $Id: update.test,v 1.15 2004/02/10 13:41:53 drh Exp $

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

# Try to update an non-existent table
#
do_test update-1.1 {

  execsql {
    UPDATE t1 SET e=e+1 WHERE a IN (SELECT a FROM t1);
    SELECT a,e FROM t1;
  }
} {1 15 2 8}

integrity_check update-12.1

# Ticket 602.  Updates should occur in the same order as the records
# were discovered in the WHERE clause.
#
do_test update-13.1 {
  execsql {
    BEGIN;
    CREATE TABLE t2(a);
    INSERT INTO t2 VALUES(1);
    INSERT INTO t2 VALUES(2);
    INSERT INTO t2 SELECT a+2 FROM t2;
    INSERT INTO t2 SELECT a+4 FROM t2;
    INSERT INTO t2 SELECT a+8 FROM t2;
    INSERT INTO t2 SELECT a+16 FROM t2;
    INSERT INTO t2 SELECT a+32 FROM t2;
    INSERT INTO t2 SELECT a+64 FROM t2;
    INSERT INTO t2 SELECT a+128 FROM t2;
    INSERT INTO t2 SELECT a+256 FROM t2;
    INSERT INTO t2 SELECT a+512 FROM t2;
    INSERT INTO t2 SELECT a+1024 FROM t2;
    COMMIT;
    SELECT count(*) FROM t2;
  }
} {2048}
do_test update-13.2 {
  execsql {
    SELECT count(*) FROM t2 WHERE a=rowid;
  }
} {2048}
do_test update-13.3 {
  execsql {
    UPDATE t2 SET rowid=rowid-1;
    SELECT count(*) FROM t2 WHERE a=rowid+1;
  }
} {2048}
do_test update-13.3 {
  execsql {
    UPDATE t2 SET rowid=rowid+10000;
    UPDATE t2 SET rowid=rowid-9999;
    SELECT count(*) FROM t2 WHERE a=rowid;
  }
} {2048}
do_test update-13.4 {
  execsql {
    BEGIN;
    INSERT INTO t2 SELECT a+2048 FROM t2;
    INSERT INTO t2 SELECT a+4096 FROM t2;
    INSERT INTO t2 SELECT a+8192 FROM t2;
    SELECT count(*) FROM t2 WHERE a=rowid;
    COMMIT;
  }
} 16384
do_test update-13.5 {
  execsql {
    UPDATE t2 SET rowid=rowid-1;
    SELECT count(*) FROM t2 WHERE a=rowid+1;
  }
} 16384

integrity_check update-13.6


finish_test