Skip to content
PHP Logo

What are some common methods to prevent multiple votes in a PHP rating script?

To prevent multiple votes in a PHP rating script, one common method is to track users who have already voted by storing their IP address or user ID along with the rating they have given. This way, when a user tries to vote again, their previous vote can be retrieved and updated instead of allowing them to submit multiple votes.

php 
// Check if user has already voted
if(isset($_SESSION['user_id']) || isset($_SESSION['ip_address'])) {
    $user_id = $_SESSION['user_id'] ?? null;
    $ip_address = $_SESSION['ip_address'] ?? null;

    $previous_vote = // Retrieve previous vote from database using $user_id or $ip_address

    if($previous_vote) {
        // Update previous vote instead of allowing multiple votes
        // Update database with new rating value
    } else {
        // Allow user to submit new vote
    }
} else {
    // Allow user to submit new vote
}

Related questions