I have a in-table class hierarchy that consists of a Person as the base class and a Doctor as a subclass. When I try moving a Person up the hierarchy tree, the discriminator value does not update. Below is my hbm file for the classes.

Hibernate v2.1.2

<hibernate-mapping>
<class name="Person"
table="PERSON"
discriminator-value="1">
<id name="personId" type="java.lang.Long" column="PERSON_ID">
<generator class="sequence">
<param name="sequence">PERSON_ID_SEQ</param>
</generator>
</id>
<discriminator type="java.lang.Integer"
column="TYPE_OF_CONTACT"/>
...
<subclass
name="Doctor"
discriminator-value="2">
...
</sublcass>
</class>
</hibernate-mapping>

Person p = (Person)session.load(Person.class, personId);
Doctor d = new Doctor();
// copy person properties to the doctor
// remove Person from the cache
session.evict(p);
session.update(d);

I receive no errors at all. The doctor information gets saved, just the discriminator does not change. I'm probably overlooking something stupid. Any help is appreciated.

Mike R.

It is not possible to downcast a persisted instance.