Hello,

First of all i'd like to say i'm not any Hibernate guru, so it might be that i'm moaning about the proper behaviour :)

I want to have two one-to-many unidirectional associations, but both mapped to the same join table, for instance:

in one class:

@OneToMany
@JoinTable(
table=@Table(name="TableName"),
joinColumns={ @JoinColumn(name="some_fk", nullable=true)},
inverseJoinColumns={ @JoinColumn(name="some_id") }
)
public Collection<Stuff> getStuff();

and in second:

@OneToMany
@JoinTable(
table=@Table(name="TableName"),
joinColumns={ @JoinColumn(name="other_fk", nullable=true)},
inverseJoinColumns={ @JoinColumn(name="some_id") }
)
public Collection<Stuff> getStuff();

The problem is Hibernate refuses to create columns with nullable set to true, even if i explicitly declare it. I traced through the code a bit and i found the following in org.hibernate.cfg.AnnotationBuilder buildAssociationTableJoinColumns() method:

currentJoinColumn.setNullable(false); //I break the spec, but it's for good

So if i understood this correctly, that "spec violation" is to make sure the column with foreign key is never null, right?
That's probably the proper behaviour for most of the cases, but in above (rare) situation it would be nice to have a few nulls here and there :)

What do you guys think about it? Maybe it should be wise to allow users override the Hibernate's default?

Thanks for the reply.

Do you have a concrete good usage? I don't.

Sorry, I did not read the begining of your post. Forget what I've said.

Do you have to use the same table for your association?
This is incredibly unintuitive, and I think Hibernate core will delete the line when you remove the relationship, so, in your case, it will remove the other one at the same time...

Not really, i'm just exploring Hibernate, thus my stubbornness :) I just wanted to make sure it's not a bug, since the 3.1 version is still under development.

Thanks for your time.

The core of Hibernate has not chagned between H3 and H3.1
We've added significant new features which add some APIs, hence the .1