When there is a uni- or bi-directional relationship of type one-to-one and many-to-one, the owner of the relationship can derive identity from the target entity.
In the Derived Identifiers list of Palette, choose a relationship type.
Click on the source entity of the relationship or press ESCAPE to cancel.
Click on the target entity of the relationship or press ESCAPE to cancel.
The Eclipse IDE creates and visualizes the relationship, as well as the relevant relationship attributes of the entities, depending on the type of relation.
To remove a particular relationship, select the relation on the JPA diagram and press DELETE , or choose Delete from the context menu.
Removing a relationship via the JPA diagram also removes it from the application data model and deletes the relationship attributes of the two related entities.