lazy many-to-many gets reset after merge?

[Pawel Veselov]

Hi.

I just noticed that I loose associated lazy loaded many-to-many collection
if I merged an updated entity. Am I missing something? I can't quite figure
exactly how cascading works...

OpenJPA 2.1.1, enhanced by PCEnhancer. Nothing funny in persistence.xml
(listerally, just list of classes), no orm file.

code:

        E_App app = em.find(E_App.class, key);
        app.setDescription(desc);
        app.setPurchased(false);
        // if I add app.getCategories() here, they don't get removed.
        em.merge(app);
        // transaction commits
        // after this point "app", when reloaded, has empty "categories"
        // I expect them to not get reset, since they are LAZY, and I'm not
touching them.

entity:

@Entity
@Table(name = "apps")
@Access(AccessType.FIELD)
public class E_App {
    @Id @Column(name="package_name")
    private String packageName;
// ...
    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinTable(name = "app_cat_map", joinColumns = @JoinColumn(name =
"package_name"), inverseJoinColumns = @JoinColumn(name = "category_id"))
    private Collection<E_Category> categories;
// ...
}

@Entity
@Table(name="categories")
public class E_Category {

    @Id
    @GeneratedValue(generator = "categoriesSeq",
            strategy = GenerationType.SEQUENCE)
    private long id;

    @ManyToMany(fetch = FetchType.LAZY, mappedBy = "categories")
    private Collection<E_App> apps;

// ...
}


Any help is greatly appreciated.

Thanks,
  Pawel.