Bug #70066 [Ver->Csd]: Unexpected "Cannot execute queries while other unbuffered queries"

Edit report at https://bugs.php.net/bug.php?id=70066&edit=1 ID: 70066 Updated by: nikic@php.net Reported by: david at grudl dot com Summary: Unexpected "Cannot execute queries while other unbuffered queries" -Status: Verified +Status: Closed Type: Bug Package: PDO MySQL PHP Version: 5.6.11 Block user comment: N Private report: N New Comment: Automatic comment on behalf of nikita.ppv@gmail.com Revision: http://git.php.net/?p=php-src.git;a=commit;h=106e7e4bca7c0fd975eb219b18e3c34957ba8657 Log: Fixed bug #70066 Previous Comments: ------------------------------------------------------------------------ [2020-12-09 16:06:55] nikic@php.net The relevant part here is that "USE" is not supported by prepared statements. MySQL returns error 1295 and PDO checks for that and falls back to emulated prepared statements. But presumably that doesn't work correctly. ------------------------------------------------------------------------ [2018-06-06 17:30:44] kbenton at activecampaign dot com kbenton@localhost  ~  php --version PHP 7.2.6 (cli) (built: May 22 2018 16:22:08) ( NTS ) Copyright (c) 1997-2018 The PHP Group Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies kbenton@localhost  ~  php testme.php Exception caught: 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. Here! kbenton@localhost  ~  cat testme.php <?php try { $pdo = new PDO('mysql:host=127.0.0.1', 'aql_app', '@ql_@pp'); $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, 0); $pdo->query('USE aql_db'); } catch ( Exception $e ) { echo "Exception caught: {$e->getMessage()}\n"; } echo "Here!\n"; kbenton@localhost  ~  ------------------------------------------------------------------------ [2015-07-13 18:32:11] david at grudl dot com Description: ------------ This code throws "SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active" on line 4. The solution is to use exec() instead of query(), but I think that it is bug since there is no other active query. Test script: --------------- $pdo = new PDO('mysql:host=127.0.0.1', '...', '...'); $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, 0); $pdo->query('USE nette_test'); ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70066&edit=1