Creating relationships for EJB 2.x beans

Use the Add Relationship wizard to specify the relationship between two enterprise beans in your EJB project or module. The appropriate finder methods are generated to support any relationships that you create.

Note: If a relationship exists between one or more CMP beans, changing the key shape of one CMP may result in the related CMPs being regenerated.

The following image shows the Add Relationship wizard with the Registration_To_Address relationship being created. A single registered user can have multiple shipping addresses on record, so the multiplicity is [0..*]. On the other hand, a shipping address has a [0..1] relationship with the registered user, and the fk_shipaddress role is added to the foreign key.


Screen capture of the Add Relationship wizard.

To create a relationship between two enterprise beans (EJB 2.x):

  1. In the Project Explorer view of the J2EE perspective, open the EJB Deployment Descriptor editor for the EJB module that includes the enterprise beans that you want to associate.

  2. On the Overview page of the editor, scroll down to the Relationships 2.0 section, and click Add. The Add Relationship wizard appears.
    Tip: When you open the wizard from the Overview page, the beans for both sides of the relationship can be edited. The wizard can also be opened from the Bean page of the editor with a bean selected.

  3. In each of the lists of beans, select one enterprise bean.

  4. In the Relationship name field accept the suggested name or type a new name for the relationship.

  5. Modify or accept the generated Role names.

  6. Specify the multiplicity for each part of the relationship.

  7. Hover your mouse pointer over either half of the diagram to specify additional role information for each role:

    • Navigable means that instances of the other bean in the association can be retrieved using this role

    • Cascade delete means that deletions will cascade to the other relationship role.

    • Foreign Key means that the specified enterprise bean of the relationship holds a foreign key for the other relationship role.

  8. Click Finish.

The following image shows the Registration_To_Address relationship in the Relationships section of the EJB deployment descriptor editor:


Screen capture of the Add Relationship wizard.

After you create a relationship, you can select the relationship in the deployment descriptor editor and click the Edit button to modify it, or click the Remove button to remove the relationship. Deleting the relationship role also deletes the relationship.

 

Related concepts

EJB relationships

 

Related tasks

Defining bean relationships