When a customer clicks this link, the server executes product.php , queries the database for the item matching id = 1 , populates the page template with that item's image, price, and description, and sends the completed HTML page to the user's browser. 2. How E-Commerce Platforms Use Database Queries
[User Browser] ---> (Clicks link: product.php?id=1) ---> [Web Server] | [HTML Page Result] <--- (Renders Template) <--- [PHP Engine] <+ (Executes: SELECT * FROM items WHERE id = 1) php id 1 shopping
Since product IDs are almost always integers, developers can explicitly force the input to be an integer before processing it. When a customer clicks this link, the server