Hibernate version: 3

Hello,

I'm fairly new to Hibernate, so excuse me if I'm misinterpreting the functionality here.

I have a class Foo, with a subclass ExtendedFoo. I want both mapped to the same table using class/subclass tags in the hibernate-mapping. But I don't want to use a discriminator column (I don't need it)...I want the Hibernate to automatically instantiate Foo objects when I do a find(). But I still want it to accept ExtendedFoo objects for saves and updates. I've looked...but I can't seem to find an example of how to do this. Does anyone here know?

Hi leptogenesis

I don't understand why you don't want to use the discriminator column for this purpose. Its the ideal way to store multiple, closely related class definitions in the same table. Plus there's no requirement to expose the discriminator-value programatically.

>>I want the Hibernate to automatically instantiate Foo objects when I do a find().
If ExtendedFoo extends Foo then doing a find on anything Foo related will return Foo compatible instances.

>> But I still want it to accept ExtendedFoo objects for saves and updates
The mapping files will specify where/how ExtendedFoo is stored so hibernate will take care of it.

Mike

I don't want to modify the table. And considering what I'm trying to do, I don't think Hibernate should force me to put a dummy value in my table which forces it to always instantiate a Foo (in fact, if I insert an ExtendedFoo, I would prefer to get a regular Foo out...)



But if I only map the Foo class, an insert of ExtendedFoo will throw an exception.



Indeed, I could always write another mapping for the class ExtendedFoo...but that would add redundancy to my code.

Sorry to double-post, but I think this deserves an update.

I've tried the most elegant kludge I can think of - I wrote another mapping which maps ExtendedFoo to the same table. This lets me do inserts fine...but then when I do a find("from Foo ..."), Hibernate returns each found value twice - once as a Foo, and once as an ExtendedFoo. This does not seem to be reasonable behavior...is there something I'm doing wrong? My only other idea is to get rid of the second mapping convert all the ExtendedFoo objects into Foo objects before inserting them...but that's terrible because it makes my code run slower.

And please let me know if you think I should post more of my code...I'm still new to the forum and don't really know what the common practices are.