In Hibernate reference chapter 10.6:
a query like " from eg.Cat as cat " returns not only Cat , it returns also subclasses of Cat.

and :

http://forum.hibernate.org/viewtopic.ph ... hism+query

How to use these subclasses that are returned base on polymorphism ? If type cast cannot be used in HQL.

There must be a way to use them, I will like to know "HOW".

I have a case here:
Class Parent
set = children : a collection of Child

Class Child

joined subclass Person

joined subclass Company

my incomplete query:

Select parent.key
from Parent parent
inner join fetch parent.children child
==>here, how to address Person that is returned by polymorphism ?
where parent.property1 = 100 and
child.property2 = 200 and
==>here, how to include only Person with property3 = 300

Please help and I am happy for any ideas and response.

/Kwan

It is me again.
Perhaps it is not possible to use the classed returned automatically based on polymorphism ?

Or am I not clear in the case description. I do not need a tailored fit answer, I need some pointers/ideas.

/Kwan

I found a solution:

Select parent.key
from Parent parent
inner join fetch parent.children child
==>here, how to address Person that is returned by polymorphism ?
Person person // get a fresh reference

where parent.property1 = 100 and
child.property2 = 200 and
==>here, how to include only Person with property3 = 300
child.id = person.id and
person.property3=100

I think so.

/Kwan