This ERD for Online Shopping Cart can assist you in searching for data patterns in your database. An ERD like this will help track customers, orders, and deliveries if you have a large shopping database. You can follow a customer's or an inventory item's purchase history through this graphical representation of your data. Creating a database for an online shopping system can present several challenges. One of the most difficult aspects of developing the shopping system is keeping all the constraints in mind. These constraints should ensure that a customer can easily log in and pay the listed price for items.