Re: Mapping hierarchy in one table problem

Just having a first superficial look.

I see in your code

GenericDAOApacheOJB<GrandChildObject, Long> grandChildProjectDao

I didn't see GrandChildObject anywere else in your mapping, but maybe I'm
not seeing well.



Shouldn't it be GenericDAOApacheOJB<GrandChildProject, Long> ?


On 2/11/08, Schmidt <[email protected]> wrote:
>
>
> Hi Armin,
>
> Thanks again.
> In order to query the database for GrandChildProject objects, I use a
> generic class that extends PersistenceBrokerDaoSupport:
>
> public class GenericDAOApacheOJB<T, PK> extends
> PersistenceBrokerDaoSupport
> {
>
>    private Class<T> persistentClass;
>
>    public T getById(PK id) throws DataAccessException{
>        return (T)
> this.getPersistenceBrokerTemplate().getObjectById(persistentClass, id);
>    }
>
> }
>
> And this is how I use the generic class:
>
> GenericDAOApacheOJB<GrandChildObject, Long> grandChildProjectDao;
> grandChildProjectDao.getById(1245L);
>
> The project identified by the id 1245 is a GrandChildProject
> (className="br.com.xxx.model.GrandChildProject"). The persistentClass
> attribute points to the correct class (GrandChildProject) but somehow OJB
> returns a ChildProject reference. I'm really stuck.
>
> One more doubt regarding mapping class hierarchy in one table. Is it
> necessary to declare all subclasses of Project in the extents section or
> just the "direct subclass"?
> Ex:
> <class-descriptor table="PROJECT_TABLE" class="br.com.xxx.model.Project">
>    <extent-class class-ref="br.com.xxx.model.ChildProject" />
>
> or
>
> <class-descriptor table="PROJECT_TABLE" class="br.com.xxx.model.Project">
>    <extent-class class-ref="br.com.xxx.model.ChildProject" />
>    <extent-class class-ref="br.com.xxx.model.GrandChildProject" />
>
> Thanks in advance!
>
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