[hibernate-dev] Natural ids and inheritance

[Emmanuel Bernard]

On 28 févr. 2012, at 17:59, Steve Ebersole wrote:

> Another discrepancy between hbm.xml and annotations currently is the 
> definition of natural ids.  hbm.xml only allows natural ids to be 
> defined on the root entity, annotations allow it to be defined on any 
> level of the hierarchy, even across classes.
> 
> We need to decide what we want to support.  2 things to consider here are:
> 1) whether we limit @NaturalId to only root entity meta (and maybe 
> @MappedSuperclass for root entities)
> 2) if we do not limit, what @NaturalId spread across a hierarchy "means"
> 
> In the second point, consider:
> class A
>     @NaturalId
>     key1
> 
> class AA extends A
>     @NaturalId
>     key2
> 
> Personally I vote for limiting @NaturalId to the root entity.  This 
> allows caching to work just like it does for identifiers.

I agree with you.