Hello,

i have the following "Table per Class" szenario: C extends B and B extends A (with C and B inheriting the primary key ("id") of A) .
Which basically means that when an Object of Type C is created. All basic properties will be stored in the superclass A where the primary key is generated, the subproperties will be stored in B, and the Type specific properties in C. With a join over all 3 Tables using the common primary key, i get the full object C.

B extends A is easy to implement in a hbm.xml file with the <joined-subclass> Tag.



But how can i implement "C extends B" , so that C inherits the primary key of B.

If there is an easier way with Annotations tell me. I am used to hbm.xml-files but its not working all the ways i tried it.

Many thx in advance!
Michael

nobody an idea ? I'm really lost!

M.

Subclasses can be nested as described below:

<class name="A">
<id name="id"><generator class="native" /></id>
<property name="..." />
<joined-subclass name="B" table="B">
<key column="id" />
<property name="..." />
< joined-subclass name="C" table="C">
<key column="id" />
<property name="..." />
</joined-subclass>
</joined-subclass>
</class>

Hello vijaybangy,

thx for your reply. But i think your example would reflect:

• B is subclass auf A
• C ist subclass of A.

What I need to describe is:

• B is subclass auf A
• C is subclass auf B

Of course this way C is also a sub-sub-class of A, you are right. But the way you put it, i would loose the relationships between B and C would I ?

Thx again for your help!

mweidlich,
In my reply above i have nested one of <joined> inside another <joined>. So it's C subclass of B.