[hibernate-dev] Natural ids and inheritance

[John Verhaeg]

I probably don't understand the complexities with this, but wouldn't the ID values in AA have to be completely independent of the values in A?

> 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.

JPAV