This is a good way to do things, but what happens if you want to persist the details of that users cart across multiple sessions? I.e., if they close the web browser and come back the next day. You could setup a login system where users register and confirm their details by replying to a confirmation email, but more often you'd like to keep your checkout as simple as possible by just letting the user enter their address and payment method and continue right through to the confirmation page.
By persisting a cookie on the users machine and by using some PHP, we can make a simple shopping cart that will store the details of what the user wants to buy. These details will remain intact, even after the user closes the browser.
So, in this article we will build a simple persistent shopping cart. We will be using PHP and MySQL to do so, so you should have intermediate knowledge of both PHP and MySQL. You will be able to take the code that we will use and adapt it to create your own simple shopping cart for your web site.