Bug #74584 [Opn->Dup]: Error about active unbuffered queries triggered unexpectedly

Edit report at https://bugs.php.net/bug.php?id=74584&edit=1 ID: 74584 Updated by: nikic@php.net Reported by: love at sickpeople dot se Summary: Error about active unbuffered queries triggered unexpectedly -Status: Open +Status: Duplicate Type: Bug Package: PDO MySQL PHP Version: 7.1.5 Block user comment: N Private report: N New Comment: Same root cause as bug #70066. Previous Comments: ------------------------------------------------------------------------ [2019-10-08 16:03:09] hadrien dot sibboni at gmail dot com Simpler : just doing the $PDO->query ('lock table foo write'); creates the same bug for me (if you have a table). (no need to $PDO->exec ('create temporary table foo (bar int)');) Isnt it the same as https://bugs.php.net/bug.php?id=70066 ? ------------------------------------------------------------------------ [2019-07-24 20:18:08] love at sickpeople dot se The main difference between exec() and query() is that exec() sends a QUERY command while query() sends PREPARE + EXECUTE + CLOSE commands. Possibly related to that? ------------------------------------------------------------------------ [2019-07-24 14:42:42] yardsoftware at gmail dot com Note : Using $PDO->exec() resolves this issue. Also make sure you do not have a semicolon when using this method. ------------------------------------------------------------------------ [2017-05-12 19:11:41] love at sickpeople dot se Version of Mysqlnd is 5.0.12-dev. ------------------------------------------------------------------------ [2017-05-12 19:07:40] love at sickpeople dot se Description: ------------ An exception is thrown in the test case below. - Emulated prepares must be OFF - "LOCK TABLE" triggers the error, eg "set @foo='bar'" does NOT I see no reason why the error occurs in this case. Test script: --------------- // Please fill in $host = ''; $db = ''; $user = ''; $pass = ''; $options = []; $options[PDO::ATTR_EMULATE_PREPARES] = false; /* required */ $options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION; $PDO = new PDO ( "mysql:host=$host;dbname=$db;charset=utf8mb4", $user, $pass, $options ); $PDO->exec ('create temporary table foo (bar int)'); $PDO->query ('lock table foo write'); Expected result: ---------------- No exception thrown. Actual result: -------------- Exception thrown. SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOState ment::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. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74584&edit=1