Mapping multi-Level inheritance in Hibernate

Currently I have a structure like this:

A
|
+--B
|
+--C

It's mapped with one table per subclass using joined tables. For historic reasons I also use a discriminator, so the current situation is as described in Section 9.1.3 of the Hibernate manual.

Question: How do I extend the mapping for a structure like this:

A
|
+--B
|  |
|  D
|
+--C

Can I <subclass> a <subclass> in the hibernate mapping? What <key>s do I need?

From stackoverflow

• not tested but, according to the link you posted if you are using hibernate3

  <hibernate-mapping>
    <class name="A" table="A">
      <id name="id" type="long" column="a_id">
        <generator class="native"/>
      </id>
      <discriminator column="discriminator_col" type="string"/>
      <property name="" type=""/>
      <!-- ... -->
    </class>
    <subclass name="B" extends="A" discriminator-value="B">
      <!-- ... -->
    </subclass>
    <subclass name="D" extends="B" discriminator-value="D">
      <!-- ... -->
    </subclass>
    <subclass name="C" extends="A" discriminator-value="C">
      <!-- ... -->
    </subclass>
  </hibernate-mapping>
  

  Henning : Seems to work. Thank you very much!

• How would this be done with annotations?

• See here - the hibernate team says: "impossible" :)

  Michal Bachman : that's an answer to the annotation question...