Bug #73299 [NEW]: Cannot change db with "use another_db" sql query

From: lubomir dot cvrk at webnode dot com Operating system: Linux, Windows PHP version: 5.6.26 Package: PDO MySQL Bug Type: Bug Bug description:Cannot change db with "use another_db" sql query Description: ------------ When \PDO::ATTR_EMULATE_PREPARES == false, and the initial connection is created with "some_db" context, the PDO is unable to run the query for changing the database (use another_db) and returns an error: Array ( [0] => HY000 [1] => 2014 [2] => 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. ) Test script: --------------- function test_pdo($prepares) { echo 'Testing PDO with \PDO::ATTR_EMULATE_PREPARES=' . ($prepares ? 'true' : 'false') . "\n\n"; $options[\PDO::ATTR_EMULATE_PREPARES] = $prepares; $db = new PDO('mysql:host=some.host.net;dbname=some_db;charset=utf8','user','password',$options); $result = $db->query('use ms_system'); echo 'After PDO::query(use another_db): '; echo $result === false ? 'PDO ERROR' : 'PDO is OK'; echo "\n"; $stmt = $db->prepare('use ms_system'); $result = $stmt->execute(); echo 'After PDO::prepare(use another_db); PDO::execute(): '; if ($result === false) { echo 'PDO ERROR - ' . print_r($stmt->errorInfo(), true); } else { echo 'PDO is OK'; } echo "\n---------------------------------------------------\n\n"; } echo '<xmp>'; test_pdo(true); test_pdo(false); Expected result: ---------------- <xmp>Testing PDO with \PDO::ATTR_EMULATE_PREPARES=true After PDO::query(use another_db): PDO is OK After PDO::prepare(use another_db); PDO::execute(): PDO is OK --------------------------------------------------- Testing PDO with \PDO::ATTR_EMULATE_PREPARES=false After PDO::query(use another_db): PDO is OK After PDO::prepare(use another_db); PDO::execute(): PDO is OK --------------------------------------------------- -- Edit bug report at https://bugs.php.net/bug.php?id=73299&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=73299&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=73299&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=73299&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=73299&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=73299&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=73299&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=73299&r=needscript Try newer version: https://bugs.php.net/fix.php?id=73299&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=73299&r=support Expected behavior: https://bugs.php.net/fix.php?id=73299&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=73299&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=73299&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=73299&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=73299&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=73299&r=dst IIS Stability: https://bugs.php.net/fix.php?id=73299&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=73299&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=73299&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=73299&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=73299&r=mysqlcfg