too long

Question

I know this question has many duplicates, but I tried several of them and none of those have been answered.

Here is my code for logout.php:

<?php
    session_start();
    require './codefiles/dbhelper.php';
    $dbh = new DbHelper();
    $dbh->Execute('UPDATE surveyors SET LoggedIn=\'0\', SessionID=\'\' WHERE Username=\''.$_SESSION['username'].'\'');
    session_unset();
    session_abort();
    session_destroy();
    $_SESSION = array();
    unset($_SESSION['username']);
    unset($dbh);
    header('location:index.php');
?>

But the session variables are just too "stubborn" to be removed. Neither session values are being cleared not the session variables are being removed. Object $dbh is being unset but not $_SESSION['username'];

Another unrelated problem, despite I am setting the LoggedIn = 0, in my SQL query, it just stays as 1 in database. LoggedIn field is of type 'bit'. SessionID field is set to blank though.

Any solutions please?

EDIT:

Removed echo $dbh->error as it was unnecessary.

EDIT 2:

Added session_destroy() as suggested by Hossam Magdy.

Answer 1

I don't know why, but the code for destroying the sessions was somehow not working in logout.php. It worked in index.php and other files, but will all sorts of unpredictable behavior.

Found a workaround to circumvent the problem. The logout.php has code as below:

<?php
    session_start();
    $_SESSION['logout'] = TRUE;
    header('location:index.php');
?>

And add this code to index.php:

# Implement logout functionality
<?php
    session_start();
    if(isset($_SESSION['logout']) && $_SESSION['logout'] == TRUE){
        foreach($_SESSION as $var => $value){
            unset($_SESSION[$var]);
        }
        session_destroy();
        session_unset();
    }
?>

It may not be a standardized solution, but the code works for me every time, with no unpredictable behavior.

Thanks everyone for sharing their ideas.