I'm pretty new at Hibernate, and I was comparing it to JDO. One of the things I liked about JDO compared to Hibernate was that in the mapping file, when you mapped the child, you specified the parent, rather than the Hibernate way of having to map all the subclasses in the same file as the parent. Any reason why Hibernate did the inheritance mapping this way?

Thanks.

Use <subclass extends="SuperClass"> in a new file with Hibernate. JDO doesn't define any mappings, by the way, you must have used a product that has proprietary object/relational mapping.

Ahhh, from reading this doc:
http://www.hibernate.org/hib_docs/refer ... tance.html
I didn't realize that the <subclass> tag didn't have to be inside the parent <class> tag, but now looking at the hibernate dtd, I see that I can :)




I don't understand what you mean when you asy that JDO doesn't define any mappings? Doesn't this dtd define (to a limited extent) how the mappings work?

http://java.sun.com/dtd/jdo_1_0.dtd

I realize that JDO leaves a lot up to whoever implements the JDO spec. But isn't the persistence-capable-superclass attribute of the class tag pretty much defined by Sun?

Thanks again for pointing out the subclass thing, I think it's much cleaner if it's in another file.

Thats not mapping metadata schema, but a simple object metadata schema that has no direct practical uses.

Ah, I see what you mean. In my head, I was just looking at the metadata as a mapping, since that's what they use to figure out what fields get stored where.

Thanks again for the help.