In modern e-commerce development, the query string is a common way to handle product additions to a virtual shopping basket. However, its usage also reveals significant security considerations that every developer and store owner should understand. What is add-cart.php?num= ?
The search result add_cart.php?num= often refers to a common URL structure in older or custom PHP e-commerce scripts where num (or a similar parameter) is used to pass a or numeric ID to a cart-handling script. Usage in PHP Scripts add-cart.php num
The most common exploitation method for the num parameter involves or Logic Errors . "add-cart
0 && $num > 0 ) // Initialize cart if it doesn't exist if (! isset ($_SESSION[ 'cart' ])) $_SESSION[ 'cart' ] = []; // 3. Update quantity logic if ( isset ($_SESSION[ 'cart' ][$product_id])) // Increment if already present $_SESSION[ 'cart' ][$product_id] += $num; else // Add as new entry $_SESSION[ 'cart' ][$product_id] = $num; // Optional: Redirect to cart page after success header( "Location: cart.php?status=added" ); exit (); else // Handle error (invalid ID or quantity) header( "Location: products.php?error=invalid_request" ); exit (); ?> Use code with caution. Copied to clipboard Essential Features to Include Cart Functions and how to do them in PHP - DEV Community product identifier The search result add_cart
: It creates a new entry in the session array with the product's details. Technical Implementation Approaches
// Redirect the user back to the cart or product page 'Location: view-cart.php' Use code with caution. Copied to clipboard Security Note
CREATE TABLE cart_items ( id INT AUTO_INCREMENT PRIMARY KEY, user_id INT NOT NULL, product_id INT NOT NULL, quantity INT DEFAULT 1, created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP );