BikeModel is an EJB that represents a particular model of motorcycle. It stores persistent information about the type, engine size, cost, and a general description. The name of the model is the primary key for this EJB.
The Bike EJB models an individual motorcycle of a particular model. In the case study, Bike has only one property: licenceNumber, that is, its license plate number (‘registration number’). In reality, of course, we may need to store more than this.
The relationship between BikeModel and Bike is one-to-many, navigable in the direction BikeModel to Bike (Figure 13.3).
In the design adopted, Bike is a dependent ...