Hi,
I have a problem putting together the right annotation syntax for creating a manytomany relation between two tables with composite primary keys, using annotations. I want hbm2ddl to generate the required assocaition table.

Hibernate version:
3.2.2 core / 3.2.1 annotations

Table1:
NationID (PK/FK)
CityID (PK/FK)
PersonID (PK)

Table2:
NationID (PK/FK)
CityID (PK/FK)
EventID (PK) Event

So I want a association table that looks like this:
NationID(FK/PK)
CityID(FK/PK)
PersonID(FK/PK)
EventID(FK/PK)

Is this kind of relation possible using annotations? When I try I get tables like this:

Table1_NationID
Table2_NationID
Table1_CityID
Table2_CityID
PersonID
EventID

What would be the way to tell hibernate that the Nation and city ID should be the same field in the two cases, using annotations? Is it possible? Or do I need to impose some constraints?

thanks in advance!

you want to share the NATION_ID across the 2 FKs, right?
This is not yet possible, this will be possible when the port of Hibernate Core formula for join columns will be done (no target time).

Yes, that was what I wanted. Thanks for clarifying that! You mention "port of Hibernate Core formula", does this mean that this functionality is actually present in Hibernate, but only through hmb.xml mappings?

yes, <formula/> inside <key/> or <many-to-one/>
Today @Formula is only usable for regular properties