how to delete session associated data .

Question

say i store some data associated with a session id in a database . how do i delete the data when the session is timeout in php(i do not want to fill my file sever with all junk data.)?

is there any call back function to call in php ?

Answer 1

Have the user with the session report back to your database every time he makes a request. (not a new row but update his row so you wont fill your db).

Then have a cronjob or something similar clean up all sessions that have a last report timestamp older than your session timeout value.

Answer 2

I don't know if this qualifies as a callback per se, but maybe you could leverage the destroy handler to remove the stale database information upon explicit session termination?

http://php.net/manual/en/function.session-set-save-handler.php

Answer 3

You can write php script

<?php
session_start();
$query = "DELETE FROM session_data WHERE session_id = '{$_SESSION['session_id']}'";
// in case you want to read this from ajax as json response
echo mysq_query($query) ? "true" : "false";
session_destroy();
?>

and access this script with ajax on uload event with JQuery

$(window).unload(function() {
    $.get('destroy_session.php', null, function(data, status) {
       // ignore result
    });
});