Use EdrawMax to create the online pizza ordering system entity-relationship diagram graphically. Online Pizza ordering system Entity-Relationship (ER) diagram can showcase all the entities that work together to make sure the ordering of any fast food is successful. There are entities like Customer, Order, Pizza, and Ingredients in an ER diagram for an online pizza ordering system. These entities have attributes like Customer_id, First_name, Last_name, House_Number, Order_id, order_date_time, delivery_date_time, total_price, order_status, pizza_id, ingredient_id, price_id, and non_pizza_id, among others. As the below online pizza ordering system ER diagram suggests, rectangles illustrate entity types, whereas ellipses represent attributes. On the other hand, lines link attributes to entity types and entity types with different relationship types.