Bi-directionnal recursive relation not refreshed in session

rkrol · **Joined:** Mon Jan 08, 2007 10:28 am **Posts:** 11

Hi,

I have a problem with a recursive bi directional relation :
- class A contains a collection of A (@OneToMany)
- class A contain a reference on the parent class A (@ManyToOne)
- in the same session :
* I persist an object A1
* I persist an other objet A2 with A1 as parent
* I make a find on the A1 id => PB : the A1.collection is not updated... it is empty (session cache version)
* It is OK if I make a refresh(A1) after the find

So my questions are :
- Am i supposed to do a refresh on A1 to force the database access and have the good version of my A1 entity (with the updated collection) ?
- Is there something wrong with the my ORM configuration ?
- Is it a hibernate bug ?

Hibernate version: 3.2.2.GA

Mapping documents:

Code:

@Entity
@Table(name = "T_SIGNALISATION")
public class Signalisation extends EntiteJpa {

    private static final long serialVersionUID = -6564628427466074308L;

    @Id
    @GeneratedValue(generator = "Signa")
    @SequenceGenerator(name = "Signa", sequenceName = "SIGNA_SEQ", allocationSize = 1)
    @Column(name = "ID", nullable = false, precision = 22, scale = 0)
    private Long id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "SIG_MERE_ID")
    private Signalisation signalisationMere;

    @Column(name = "LIBELLE", nullable = true)
    private String libelle;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "signalisationMere")
    private List<Signalisation> signalisationsFilles = new ArrayList<Signalisation>(0);

    public List<Signalisation> getSignalisationsFilles() {
        return signalisationsFilles;
    }
    ...

Code between sessionFactory.openSession() and session.close():

Code:

        // SIGNALISATION CREATION
        Signalisation sig = new Signalisation();
        sig.setLibelle("TestLibelle1");
        signalisationDao.persist(sig);
        signalisationDao.flush();

        // SIGNALISATION CREATION
        Signalisation sigFille = new Signalisation();
        sigFille.setLibelle("TestLibelleFille1");
        sigFille.setSignalisationMere(sig);
        signalisationDao.persist(sigFille);
        signalisationDao.flush();

        sig = signalisationDao.find(sig.getId());
        //signalisationDao.refresh(sig);    // test pass with this line (force the database access)
        List<Signalisation> l = sig.getSignalisationsFilles();
        assertNotNull(l);
        assertEquals("Liste des sig filles non complete", 1, l.size());
        assertEquals("Mauvaise Sig fille", l.get(0).getId(), sigFille.getId());

Best regards,
Rudy

schauder · **Joined:** Thu Jul 05, 2007 9:38 am **Posts:** 287

You are supposed to keep the references in sync yourself.

if a1 references a2, you have to make sure a2 references a1, before you save it in the database.

If you don't do that it actually is next to random which state (with or without) the referenc is stored in the database

This is one of the many reasons why I recommend to avoid bidirectional references if possible.

regards
Jens