Bug #67004 [NEW]: Executing PDOStatement::fetch() more than once prevents releasing resultset

From: php_bugs at multiwebinc dot com Operating system: Ubuntu PHP version: 5.5.10 Package: PDO MySQL Bug Type: Bug Bug description:Executing PDOStatement::fetch() more than once prevents releasing resultset Description: ------------ When executing PDOStatement::fetch() more than once on the same statement, the resultset is not released and subsequent calls to PDO::prepare() produce the error: "Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.'" My PHP is PHP 5.5.3-1ubuntu2.2 and MySQL 5.5.35 on Ubuntu 13.10, however this bug doesn't appear to affect all versions since someone else tested it using the same code and was unable to produce the error unless PDO::MYSQL_ATTR_USE_BUFFERED_QUERY was set to false. See this thread I started here: http://stackoverflow.com/questions/22803938/what-is-causing-pdo-error-cannot-execute-queries-while-other-unbuffered-queries#22805988 Test script: --------------- The following works, however uncommenting the two lines that are commented produces the error above. <?php $dbh->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); $dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true); $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $stmt = $dbh->prepare("SELECT ?"); $stmt->execute([0]); $result = $stmt->fetch(); // $stmt->execute([0]); // Uncomment these lines for error // $result = $stmt->fetch(); $stmt = $dbh->prepare("SELECT ?"); $stmt->execute([0]); $result = $stmt->fetch(); Expected result: ---------------- I would expect that executing a prepared statement more than once would not have any effect on whether the unbuffered queries are released or not. It should perform just like the first time. -- Edit bug report at https://bugs.php.net/bug.php?id=67004&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=67004&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=67004&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=67004&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=67004&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=67004&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=67004&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=67004&r=needscript Try newer version: https://bugs.php.net/fix.php?id=67004&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=67004&r=support Expected behavior: https://bugs.php.net/fix.php?id=67004&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=67004&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=67004&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=67004&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=67004&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=67004&r=dst IIS Stability: https://bugs.php.net/fix.php?id=67004&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=67004&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=67004&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=67004&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=67004&r=mysqlcfg