I need to map the same table to 2 different classes where there is no discriminator. I've tried this

<class name="com.abc.Recoverer" table="RSASRECV" >
....


<class name="com.abc.FinancialAdjuster" table="RSASRECV">
.......


but it fails on the instanceAlreadyLoaded() method of Loader with WrongClassException.



I have been using the Jaxor O/R tool up until now and that lets me achieve the above.

Can I do the same in Hibernate?

In HB2.x, you can't have two objects representing the same row associated with a session at the same time. I actually changed this in HB3, after thinking about it some more.

OK, but what about the case of Lightweight versions of heavywiehgt classes?

In the reference manual it says:

"Explicit polymorphism is useful when two different classes are
mapped to the same table (this allows a "lightweight" class that contains a subset of the table columns)."


Are you saying that the above is not really achievable?

No of course not. Re-read what I wrote (difference between "object" and "class").

Thanks for your help. This is how I understand it:
If I attempt to load a lightweight object and a heavyweight object from the same table, that works fine UNLESS they both happen to point to the same row in that table in which case I'll get the WrongClassException.

Therefore I'm free to map Lightweight and Heavyweight classes to the same table but I run the risk of getting a WrongClassException at runtime.

I guess you sort of can:)

I have managed to use Lightweight versions of heavywiehgt by using native query to get Lightweight.

My solution is:
1 I have defined
<class name="Lightweight " table="aTable">
</class>
<class name="Heavywiehgt " table="aTable">
</class>

2. use native sql query "select {co.*} from aTable" to get Lightweight

So far it works fine - but still this is workaround.

Does anyone have better idea?