hi,

i'm connecting to my database and placing the connection in a variable like so

<?php

$conn = mysql_connect("localhost", "*", "*");
$db = mysql_select_db("theuther_content", $conn);

$_SESSION['conn'] = $conn;

?>

and calling to it as normal.

However on one of my pages i am using session_unset(); to help a logout process...

<?
session_unset();
unset($_SESSION['blogger']);
unset($_SESSION['auth']);

if (empty($_SESSION['blogger'])) {
	echo "Logged Out";
}
else {
	echo "NOT Logged Out";
}
?>

and then when i call to $conn later in my page i get an error saying that the link identifier is invalid.

I assume that when $_SESSION['conn'] is unset the contents of it are unset (the $conn variable), but why does this happen?

    are you calling to $conn later on the same page where it was created?
    i have tried replicating this problem on 2 different servers but my $conn variable still lives even after unsetting the session and destroying the variable.

    p.s. as per the php manual, you should not use session_unset() if you are using $SESSION or $HTTP_SESSION_VARS.

    also the line
    if (empty($    SESSION['blogger'])) {
    would work better if it was
    if (!isset($_SESSION['blogger'])) {
    since you destroyed the variable 3 lines up.

      yeh i am calling to it through a normal query

      $qry = mysql_query($sql, $conn) or die(mysql_error());

      as for the session_unset i got rid of that so my problem has gone

      <? 

$_SESSION['blogger'] = "";
$_SESSION['auth'] = "";

unset($_SESSION['blogger']);
unset($_SESSION['auth']);

if (!isset($_SESSION['blogger'])) {
	echo "Logged Out";
}

else {
	echo "NOT Logged Out";
}

?>

      but why did $conn not work after i used session_unset ??

        if you are familiar with c++ and pointers, my original thought was that since $conn was a resource variable $SESSION['conn'] was a pointer to $conn so when you unset the session variable, it unset the $conn variable too. but that is what i tried testing on my own machines and it wasnt the case. somehow the two must have been linked together by doing $SESSION['conn'] = $conn;

        in c++ i thought it would be equivalent to
        _SESSION['conn'] = &conn;
        so the session var points to conn and any changes to the session var really change the conn var so closing the connection of the session var would close conn too.

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