Update sql table on logout

Question

I want to update a table field on successful logout. But my code doesnt seem to work.

Below is my code. It destroys the session but it doesnt update the table field.

<?php
session_start();
if (session_destroy()) {
    include "lib/session.php";
    include "lib/mysql.php"; 
    $session_id = $_SESSION['grammarly_sessid'];
    $q=mysqli_query("update online_status set status='OFF' where id = '$session_id'");
} else {
    exit;
}

unset($_SESSION['grammarly_sessid']);
session_start();
session_destroy();
header('location:../login.php')
?>

Please help.

Answer 1

You need to fetch the session ID before you destroy the session.

You also need to pass the MySQLi identifier to the first parameter of the mysqli_query() function if you are not using it as an OOP object.

<?php
session_start();
$session_id = $_SESSION['grammarly_sessid'];

$mysqli = mysqli_connect('localhost', 'mysql_user', 'mysql_pass');
mysqli_select_db($mysqli, 'database_name');

if(session_destroy())
{
include "lib/session.php";
include "lib/mysql.php"; 
$q=mysqli_query($mysqli, "update online_status set status='OFF' where id = '$session_id'");
}
 else{
exit;
}

header('location:../login.php')
?>

Answer 2

session_start();
include "lib/session.php";
include "lib/mysql.php"; 
$session_id = $_SESSION['grammarly_sessid'];
$q          = mysqli_query("update online_status set status='OFF' where id = '$session_id'");    
unset($_SESSION['grammarly_sessid']);
session_destroy();
header('location:../login.php');

here in this case, you don't have to add a condition..