JPA: Foreign key that is also a primary key mapping

Question

I have been trying to solve this for whole day but no luck! Also i tried to read most of the tutorials on the net but as you all know they all are full of useless examples t

Answer 1

I know this is very old qs, but for completeness of your case you can just have (jpa 2.0)

@Entity
@Data
public class Vehicle implements Serializable{
   @Id
   @GeneratedValue
   private long vehicleId;
   .. //other props
}

@Entity
@Data
public class VehicleExtras implements Serializable{
         @Id
         @OneToOne (cascade = CASCADE.ALL)
         @MapsId
         @JoinColumn(name ="vehicleId")
         private Vehicle vehicle;

         @Column  
         private boolean allowSmoke; 
         ..// other props.
}

should share same pk/fk for VehicleExtra table