Hibernate version: 3.0.5

I would like to have "mapped" polymorphism AND explicit polymorphism, but after much research, can not figure out how to do this, or if it is possible.

I want "mapped" polymorphism for polymorphic associations, for updates.

I do not want implicit polymorphism for polymorphic queries, because I have a superclass and 70+ immediate subclasses, so polymorphic queries would not be practical. I will only need to query for superclass instances, OR a specific subclass instance.

For example, using table per subclass:
superclass:
public class SuperClass {
private Long id;
private String name;
//constructor,getters/setters
}
<hibernate-mapping>
<class name="SuperClass" table="SuperClass" polymorphism="explicit">
<id name="id" type="long">
<column name="id" not-null="true"/>
<generator class="identity"/>
</id>
<property name="name" type="string"/>
</class>
</hibernate-mapping>

example of one of 70+ subclasses:
public class SubClass extends SuperClass {
private Long id;
private Integer value;
// constructor, getters,setters
}
<hibernate-mapping>
<joined-subclass name="SubClass" table="SubClass" extends="SuperClass">
<key column="id"/>
<property name="value" type="integer"
</joined-subclass>
</hibernate-mapping>


If i use this HQL query, Hibernate will join SuperClass to all <joined-subclass> subclasses, which is not practical given the number of subclasses.
<query name="SomeQuery">
from SuperClass sc
where sc.name = :name
</query>

Is there a way to use HQL to query on just the SuperClass without joins to all subclasses ? Or any design suggestions ?

Have you tried what you're talking about using just polymorphism="implicit" ?

I'm pretty sure that if you select on the SuperClass, you'll get all of them, and if you select on any of the subclasses, you'll get only the subclass(es)

When updating, polymorphism shouldn't be an issue.

Thanks. Yes, I first tried implicit and that resulted in the problem, so I changed to explicit polymorphism to try to solve it.

I found another post which addresses my problem. What I am trying to do is not consistent with OO approach.

http://forum.hibernate.org/viewtopic.ph ... lymorphism

For my purposes, I was able to get around the problem by just selected the individual properities I needed (a report query), e.g.

<query name="SomeQuery">
select sc.id, sc.name
from SuperClass sc
where sc.name = :name
</query>

With this query, Hibernate does not join to the subclass tables, and given that I have 70 subclasses, this is the behavior I want.

Thanks for suggestion.