mapping table not populated

medotin · **Joined:** Sun Jan 13, 2008 1:13 pm **Posts:** 9

The entities on both sides of the relationship get data in their tables, but the mapping table remains empty. I don't see anything wrong, so I'm hoping someone here will.

The entities are Person and Circle and can be found here:
http://gifttracker.googlecode.com/svn/t ... ircle.java
http://gifttracker.googlecode.com/svn/t ... erson.java

If nothing is wrong with the entities, perhaps something is wrong with how they get persisted. That place, which correctly saves the entities but not their mapping, is here:
http://gifttracker.googlecode.com/svn/t ... eImpl.java

If you look at createAndJoinCircle, that is where the relevant code is. Here is the snippet which does the work:
Circle c = inner.get().createCircle(loggedInUser, name, password);
inner.get().joinCircle(loggedInUser, c);

If I step through in debug mode, the Person does have the circle instance in its 'circles' set right before it's merged. I've also tried adding the person to the circle, but that didn't help.

Thanks for any ideas,
Brian

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

Could you post the mapping file, to see if the many-to-many relationship is generated correctly?

medotin · **Joined:** Sun Jan 13, 2008 1:13 pm **Posts:** 9

What do you mean? The relationship is defined in the classes, with annotations. Perhaps Hibernate can generate some "mapping file" I'm not aware of? Explain further please.

gonzao_diaz · **Joined:** Mon Nov 26, 2007 2:29 pm **Posts:** 443

No, I am sorry. With annotations you don't need the mapping files. It is not like XDoclet.
Unfortunately I can't help you here, until I learn a little more about annotations myself.

andydale · **Posted:** Tue Jan 15, 2008 6:54 am

Hi,

Do you have any CASCADE attribute set on the @ManyToMany annotation, like below ?

Code:

 
    @ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE})
    @JoinTable(name = "course_student",
                joinColumns = @JoinColumn(name = "course_id", referencedColumnName = "course_id"),
                inverseJoinColumns = @JoinColumn(name = "student_id", referencedColumnName = "student_id"))   
    public Set<Student> getStudents() {        
        return mEnrolledStudents;
    }

Cheers,

Andy

medotin · **Joined:** Sun Jan 13, 2008 1:13 pm **Posts:** 9

No, I have no cascade attributes. However, in my case I first make sure both entities are persisted and only then do I merge the entity which references the other in its collection. That is, by persisting each entity myself, cascade isn't needed, no?

damnhandy · **Posted:** Mon Jan 21, 2008 11:49 am

Hi Brian,

I am seeing the same problem with my application as well. My annotation mappings are similar to yours, and I am not seeing the join tables populated. Oddly enough, when I load the entity, the related entities load just fine, even though there's not data in the join table. I'm stumped.

Ryan-

medotin · **Joined:** Sun Jan 13, 2008 1:13 pm **Posts:** 9

I tried upgrading to the latest versions of hibernate (core, annotations, entity manager), and this problem seems to be fixed. I hope you have the same experience.