Take a look in OpenJPA's FetchGroup construct to see if this meets your needs.
http://openjpa.apache.org/builds/2.4.0/apache-openjpa/docs/manual.html#ref_guide_fetch Albert On Wed, Feb 24, 2016 at 10:49 PM, Alejandro Abdelnur <tuc...@gmail.com> wrote: > Hello, > > I've spent quite a bit of time searching around without any luck. > > With OpenJPA 2.x, is it possible to get the foreign key of a OneToOne > relationship in the source without loading the target entity? > > For example: > > public class A { > @Id > private String id; > private String name; > @OneToOne(fetch = FetchType.LAZY) > private B b; > ...getters/setters > } > > public class B { > @Id > private String id; > private String name; > ...getters/setters > } > > Even if 'A a = em.find(A.class, "1")' loads the columns 'ID, NAME, B_ID' > from A if I do 'a.getB().getId()' this triggers a new query on B to get ID. > > The closest related thing I found is > > http://stackoverflow.com/questions/2593722/hibernate-one-to-one-getid-without-fetching-entire-object > , but this does not seem to apply to OpenJpa. > > Similarly for ManyToOne relationships? > > Thanks in advance. > > Alejandro > -- Albert Lee.
