checking session data using id, and changing id within a loop - php

Question

I'm doing a little server-side project, where I need to check if a session variable is set, using session id's that are stored in my database.
The problem I'm getting, is that I don't want to destroy the session after I've checked if the variable is set. So I need a way to either check the variable without having to start the session, or find a way to change to a different session id while the session is started,
or duplicate the session to a different session that I can destroy.
Here's what I have:
while(true) {
$stmt=$db->prepare("SELECT sessionid FROM sessions");
$stmt->execute();
while($row=$stmt->fetch(PDO::FETCH_ASSOC) {
session_id($row['sessionid']);
session_start();
if(!isset($_SESSION['value'])) {
$stmt=$db->prepare("DELETE FROM sessions WHERE sessionid=:sessionid");
$stmt->bindValue(':sessionid',$row['sessionid'],PDO::PARAM_STR);
$stmt->execute();
}
session_destroy();
}
sleep(5);
}

Answer 1

Done it Lol ...
while(true) {
$stmt=$db->prepare("SELECT sessionid FROM sessions");
$stmt->execute();
while($row=$stmt->fetch(PDO::FETCH_ASSOC) {
session_id($row['sessionid']);
session_start();
session_regenerate_id(false);
$newsessionid=session_id();
session_write_close();
session_id($newsessionid);
session_start();
if(!isset($_SESSION['value'])) {
$stmt=$db->prepare("DELETE FROM sessions WHERE sessionid=:sessionid");
$stmt->bindValue(':sessionid',$row['sessionid'],PDO::PARAM_STR);
$stmt->execute();
}
session_destroy();
}
sleep(5);
}
Reference: http://uk1.php.net/manual/en/function.session-regenerate-id.php