@UniqueConstraint check multiple tables in JPA

Question

On campus, the @OneToMany Building Building has @OneToMany Rooms. Room names must be unique on campus (e.g., campus-A, block-A, room-A and campus-B, block-A, room-A must be saved)

Is it possible to define such a unique constraint for the Room object?

Answer 1

Maybe I'm missing something, but they don’t build names that are unique on campus? Therefore, you need to make sure that the room names are unique within the given building:

@Entity @Table(name="rooms", uniqueConstraints = {@UniqueConstraint(columnNames={"building_id","name"})} ) public class Room { ... @ManyToOne @JoinColumn(name = "building_id") private Building building; ... } 

If you are now doing the same for the Building names inside Campus , you should be good to go.