#40869 [NEW]: Mysql gives incorrect result, using subqueries and variables

From: robert dot allen at unearthtravel dot com Operating system: PHP version: 5.2.1 PHP Bug Type: MySQL related Bug description: Mysql gives incorrect result, using subqueries and variables Description: ------------ Hi We are getting an odd result when submitting a query to a mysql server (4.1.10), we get a different result when performing the query through php (an incorrect result) as opposed to straight in to a mysql client. It seems to have performed the sub-query twice, so the variable @j has been incremented twice. A simplified version of our code is shown below and reproduces the problem, I have also included a sample table. I have seen it on both windows and linux. Reproduce code: --------------- mysql_query("SET @j=0;"); $sql = "select offset from (select @j:=@j+1 as offset, if(element_id=2,1,0) as result from element) as t1 WHERE t1.result=1 "; $result = mysql_query($sql); $row = mysql_fetch_row($result); echo $row[0]; /******************DATABASE****************/ CREATE TABLE element ( element_id int(10) unsigned NOT NULL auto_increment, element_type_id int(10) unsigned NOT NULL default '0', lock_level int(10) unsigned NOT NULL default '0', PRIMARY KEY (element_id), KEY new_index (element_type_id) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; /*Data for the table element */ insert into element(element_id,element_type_id,lock_level) values (1,1,0); insert into element(element_id,element_type_id,lock_level) values (2,10,0); insert into element(element_id,element_type_id,lock_level) values (3,2,0); insert into element(element_id,element_type_id,lock_level) values (4,10,1); insert into element(element_id,element_type_id,lock_level) values (5,2,0); Expected result: ---------------- 2 Actual result: -------------- 7 -- Edit bug report at http://bugs.php.net/?id=40869&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=40869&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=40869&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=40869&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=40869&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=40869&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=40869&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=40869&r=needscript Try newer version: http://bugs.php.net/fix.php?id=40869&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=40869&r=support Expected behavior: http://bugs.php.net/fix.php?id=40869&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=40869&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=40869&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=40869&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=40869&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=40869&r=dst IIS Stability: http://bugs.php.net/fix.php?id=40869&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=40869&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=40869&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=40869&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=40869&r=mysqlcfg