Manually specify the value of a primary key in JPA @GeneratedValue column

Question

I\'m having an Entity which has a primary key / id field like the following:

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
         


        

Answer 1

Using GenerationType.SEQUENCE with PostgreSQL and EclipseLink worked for me.

1) Change

@GeneratedValue(strategy = GenerationType.IDENTITY) 

by

@GeneratedValue(strategy=GenerationType.SEQUENCE, generator="step_id_seq")
@SequenceGenerator(name="step_id_seq", sequenceName="step_id_seq")

Now, you can call sequence using NativeQuery:

return ((Vector) em.createNativeQuery("select nextval('step_id_seq')::int").getSingleResult()).get(0);

and set the returned Id to your Entity before call EntityManager.persist() method.

Hope it's not too late!