Hi,

I've got to make the Hibernate mapping for an existing Oracle DB schema.
It contains a one-to-one relationship between the instances of the same type, however it's been done the way many-to-many relations are:

There's a table for the entity instances, let's call it ENTITY, it has an id field and several property fields. There's another table called ENTITY_REL which contains two fields for the two ends of the relation, so each of them is a foreign key if ENTITY's id field. ENTITY_REL has also some other properties.

Again this lineup looks like a basic many-to-many relation mapping however, I know it's one-to-one. I would like to know if it's possible to let Hibernate know, it's a one-to-one relation, i.e. to create the appropriate Hibernate mapping. I currently have a many-to-many mapping, but not too happy with it..

Regards,

Zoltan

As I understand one-to-one relations doe's not exist in databases, if you have it then put all attributes to the same table (declare nullable attributes last to save space if it was designed for this reason) and create two views for it, you can map this stuff as components too.

Hi,

I think I was unclear: the database schema is given (unmodifiable), and I have to act upon it. So what I'd like to know if it's possible to create a Hibernate mapping that handles this schema as a one-to-one relation

Regards,

Zoltan