Application Developer supports three mapping strategies for entity beans and relationships:
Top-down— From entity beans to new tables
Bottom-up— From existing tables to new entity beans
Meet-in-the-middle— Map entity beans to existing tables
Figure 12-1 summarizes the three approaches.
Figure 12-1. Mapping strategies for CMPs
In the sections that follow, we look at the three strategies in detail.
The top-down approach is the easiest to handle, because no legacy database is imposed on you (Figure 12-2). You have full freedom to design the entity beans.
Figure 12-2. EJB mapping: top-down approach
The top-down approach ...