Doc #69730 [Com]: PDO: incorrect description of how to close the connection to the database

Edit report at https://bugs.php.net/bug.php?id=69730&edit=1 ID: 69730 Comment by: 37xzxz at gmail dot com Reported by: 37xzxz at gmail dot com Summary: PDO: incorrect description of how to close the connection to the database Status: Feedback Type: Documentation Problem Package: Documentation problem PHP Version: 5.6.9 Assigned To: cmb Block user comment: N Private report: N New Comment: I think documentation should be updated to actual state. cappytoi posted his note 1 year ago. I though that bug already exist somewhere here. But I failed to find it. I reproduced this issue on php-5.5.14-Win32-VC11-x86 and php-5.6.9-Win32-VC11-x86: I run php script and check MySQL using following query SELECT ID, USER, HOST, DB, COMMAND, TIME, STATE, LEFT(INFO, 51200) AS Info FROM information_schema.PROCESSLIST; I see connection from host with php script during 10 seconds. Previous Comments: ------------------------------------------------------------------------ [2015-05-29 14:31:14] cmb@php.net Actually, cappytoi's note shouldn't be there at all. It is explained that bug reports & missing documentation shall not be posted as user contributed note, but rather a respective bug report should be filed[1]. I'm reluctant to reject the note now, as it already has been upvoted by a lot of users, so seems to be important. Anyhow, I'm neither able to reproduce the mentioned behavior of your test script with PHP 5.5.25 nor 5.6.9. I can, however, reproduce it with PHP 5.4.19. Did you really test this with PHP 5.6.9? If not, please do, and report back (don't forget to set the status of this ticket to "open" after doing so) – there may actually be a bug. Otherwise "only" the documentation would have to be improved. The respective statement is misleading at best: | To close the connection, you need to destroy the object by | ensuring that all remaining references to it are deleted--you do | this by assigning NULL to the variable that holds the object. Actually, assigning NULL to the variable that references the PDO instance will not close the connection, if there are still other references to this very instance (such as from a PDOStatement instance, or from other variables referencing the same PDO instance). These have to be removed also (for instance, by assigning NULL to the variable that references the PDOStatement). Of course, this can be automated by encapsulating the query execution in a function (or method for that matter), in which case the PDOStatement will be freed when the function returns. [1] <https://php.net/manual/add-note.php?sect=pdo.connections.php#whatnottoenter> ------------------------------------------------------------------------ [2015-05-29 11:28:35] 37xzxz at gmail dot com Description: ------------ --- From manual page: http://www.php.net/pdo.connections --- I can't find bug about what cappytoi wrote in his comment https://php.net/manual/en/pdo.connections.php#114822 "You shouldn't expect that your connection is closed when you set $dbh = null unless all you do is just instantiating PDO class." $stmt = null; // doing this is mandatory for connection to get closed In fact this works if you use PDO::prepare and PDOStatement::execute. If you use direct PDO::query and query contain some error "$stmt = null;" also doesn't close the connection. Test script: --------------- <?php $pdo = new PDO( 'mysql:host=localhost;port=3306;dbname=world', 'user', 'password' ); try { $stmt = $pdo->query('SELECT * FROM city1nonexisttable'); } catch (PDOException $e) { $errorText = $e->getMessage(); var_dump($errorText); } $stmt = null; $pdo = null; sleep(10); ?> Expected result: ---------------- The connection to the database will be closed after $pdo = null; as described in documentation. Actual result: -------------- The connection to the database remains active after $pdo = null; and hangs 10 seconds. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=69730&edit=1