Am creating a website where people can leave their opinions on releases by rating them and this gets stored into a MySQL database which is driven by PHP.
I have a feedback form for one particular release, which (lets say in this example) has the ID of 35. When I send a user another one which has the ID of 36 and the user has both windows open, the PHP processing code stores the responses from ID 35 but with ID 36. The page redirects to the previous page when the database already has a 'reaction_reacted' value of '1'.
Is there a way to solve this?
Here is an example of my code. The $promo_id, reaction_id and username are passed to it from the previous page when submission occurs.
session_start();
include 'connect.php';
mysql_connect($host,$db_user,$db_password);
mysql_select_db($database);
$promo_id = $_SESSION['promo_id'];
$reaction_id = $_SESSION[reaction_id];
$username = $_SESSION['username'];
if(isset($_SESSION['username']))
{
// Check to see if Receipt and DJID values are entered
$queryb = "select reaction_ID from reactiondata where reaction_ID='$reaction_id' AND reaction_username='$username' AND reaction_promoID='$promo_id' and reaction_reacted='1'";
$result2 = mysql_query($queryb) or die(mysql_error());
while($row = mysql_fetch_array($result2)){
header('Location: ' . $_SERVER['HTTP_REFERER']);
// session_destroy();
// exit;
}
if ($reaction_id && $promo_id != null)
{
$p4support = $_POST['DJsupport'];
$p4favouritemix = $_POST['FavMix'];
$p4score = $_POST['score'];
$p4comment = $_POST['DJcomment'];
$query = "UPDATE reactiondata SET reaction_username='$username', reaction_promoID='$promo_id', reaction_support='$p4support', reaction_favouritemix='$p4favouritemix', reaction_score='$p4score', reaction_comment='".mysql_real_escape_string($p4comment)."', reaction_reacted='1' WHERE reaction_ID='$reaction_id'";
mysql_query($query) or die('Error in MySQL query. Here is the error message: '.mysql_error());
$query7 = "UPDATE reactiondata SET reaction_time=NOW() WHERE reaction_ID='$reaction_id'";
mysql_query($query7) or die('Error in MySQL query. Here is the error message: '.mysql_error());
}
Thanks
CP
P.S I know I am using depreciated mysql_query methods, I just want the page to function properly before I start preventing SQL Injection attacks.
The easiest solution (one of the...) is to add the reaction_id as a hidden form field to the form instead of using a session. That way the reaction is always linked to the correct ID when the form is posted.
You should not use a session for that as the session will span all open windows and tabs in the browser so it is not suitable to maintain the state of a specific tab.