The example database supports the operation of a pizza and fast food delivery company. It contains information about the products (relation ProductType) and their deliverables (relation Product). A product may have many deliverables, for example, a small, medium and a large one, distinguished by the ModelID attribute. The products belong to categories that are to be listed in a specified order in a price list. This order is defined in the relation Category. The database contains also information about the materials (relation Material) and their usage in products (relation Contents). Some of the materials are also available as add-ons for an extra fee given by the attribute AddOnPrice. All the prices are in euros.
The database supports the production of a multi-lingual price list. The names of the products, product categories and materials in different languages are stored in the relation ObjectName. The relation Object contains the identifiers for products, product categories and materials, and guarantees that the same identifier is used for only one object. Customer data is stored in the relation Customer. Relation Order contains the orders the customers have made. It contains both undelivered and already delivered orders. Relations ItemOrdered and AddOn specify what has been ordered. After an order has been made its delivery is assigned to one of delivery boys. This assignment is registered in the relation Delivery. The relation DeliveryBoy contains information about delivery boys or girls. In each Delivery-tuple the attribute DeliveredBy may not contain null values. DateDelivered and TimeDelivered are assigned values after the delivery has taken place.
The database contains also data about the company cars used by delivery boys and girls. Car specific information is stored in relation Car. The Driver relation describes the usage of cars. If a delivery boy has been in an accident with a car, this is registered in the relation Accident. The attribute Role in this relation indicates whether the delivery boy was a victim or to be blamed of the accident. Cars are inspected annually. Inspections are registered in the relation Inspection. Problems found in these inspections are registered in the relation Problem.