Tutorial 2: (Configuration) Adding Custom Dependency

There are many systems which doesn't have proper foreign key relationship. In order to create relationship with other entities, random-jpa provides dependencies to be added to JPAContextFactory. Based on these provided custom dependencies and foreign key relationship, a JPAContext is created.

Adding custom dependency

Let us say that you want have a custom dependency between Person and Employee tables but you do not have any foreign key relationship between them. We will have create Dependencies for this using javax.persistence.metamodel.Attribute objects. (Here Person_ & Employee_ are SingularAttributes)

final Dependencies dependencies = Dependencies.newInstance();
dependencies.withLink(Link.newLink(Employee_.personId, Person_.id));

JPAContext jpaContext = JPAContextFactory.newInstance(Database.ORACLE, entityManager)
    .with(dependencies)
    .create();

Represents, Employee's personId has a foreign key relation to Person's id.