This chapter not only introduces container-managed persistence (CMP), but it also stresses the importance of relationships between entity beans. Entity bean structure is similar, whether you're using CMP or BMP. However, with CMP, the container generates code based on abstract access methods and declarative information provided by the bean developer during deployment.
Here are the key points from this chapter.
Entity beans model business data. Each entity bean in general maps to a corresponding row in a database.
Entity beans have a unique primary key that maps to the underlying database primary key.
If CMP entity beans are related (for example, the Customer EJB is related to zero or more Order EJBs), then we use container-managed ...