I'm sure I am missing something in the documentation to solve this problem but I need a push in the right direction. At this juncture, I seem to have part of the problem licked but not all... more on the exact problem after setting the context.
I have a class that has multiple sub-classes. I want to create a class that contains references to these various sub-classses:
class Container {
PartA partA;
PartB partB;
}
class Part {
String name;
}
class PartA extends Part {
}
class PartB extends Part {
}
I have created a mapping that looks like this:
<class name="Container" table="CONTAINER">
<id name="id" column="ID" type="long">
<generator class="identity"/>
</id>
<many-to-one name="partA" column="PARTA" class="PartA" not-null="false" cascade="all"/>
<many-to-one name="partB" column="PARTB" class="PartB" not-null="false" cascade="all"/>
</class>
<class name="Part" table="PART">
<id name="id" column="ID" type="long">
<generator class="identity"/>
</id>
<discriminator column="class" type="string"/>
<property name="name" column="NAME" type="string" length="128" not-null="true"/>
...
<subclass name="PartA"/>
<subclass name="PartB"/>
</class>
The way my application needs to work, you can have a Container in existence before any parts are added. My code to add a Part to an existing Container looks like:
// while in Hibernate session:
PartA partA; // assume valid PartA
container.setPartA(partA);
hibSession.update(container);
What I am experiencing is that I am able to save the Part sub-classes successfully, but the reference from the Container to PartA or PartB is always null. It's as if the relationship does not exist to Hibernate.
What am I missing? I have not worked with subclasses in this way before.
Thanks in advance,
-Andre'
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