using discriminator with joined-subclass

aranganath · **Joined:** Tue Feb 17, 2004 3:09 pm **Posts:** 2

Is there anyway to use a discriminator with a joined subclass? In our situation, we have a poorly designed legacy schema, where each flavor of our base domain object has it's unique properties in their own table. For example, we have a Automobile table and then a Car and Truck table. The Automobile table holds the common properties, and the Car and Truck tables hole the properties unique to cars and trucks.

Ideally, I'd like to be able to ask hibernate for an automobile by primary key, and it will return the corresponding car or truck object. I can put a type code on in the Automobile table to assist it, but major changes to the schema can't be made for legacy reasons.

Any ideas?

tcollins · **Posted:** Tue Feb 17, 2004 3:23 pm

Why do you need to use a discriminator? It seems like just using a <joined-subclass> will solve your problem. Check out chaper 16.1 in the docs.

Code:

<class name="Automobile table="AUTOMOBILE">
<id name="id" type="long" column="AUTO_ID">
<generator class="native"/>
</id>
...
<joined-subclass name="Car" table="CAR">
<key column="AUTO_ID"/>
...
</subclass>
<joined-subclass name="Truck" table="TRUCK">
<key column="AUTO_ID"/>
...
</subclass>
</class>

emmanuel · **Posted:** Tue Feb 17, 2004 3:31 pm

and

Code:

session.load(Automobile.class, myId);

will do the job

aranganath · **Joined:** Tue Feb 17, 2004 3:09 pm **Posts:** 2

Well what do you know, no need for the discriminator. I'm not sure why I thought I needed it. We've had the if/then statement from hell to deal with this.[/code]