My question references the example query <from eg.Cat cat where cat.class = eg.DomesticCat>, chapter 10.7, Hibernate2 Reference Documentation.

1.) Additionally to the query example, I would like to query also the name from DomesticCat, e.g. <and name = 'ALEX'>. How would it look like in the example? If I write <and cat.name = ?> I get an exception like 'property unknown'.

2.) How do I query, if I work with <joined-sublass>. Is there a way to query attributes on joined subclases, see the example above. Currently I'm not able to do so.

Note:
As already mentioned in different postings "class" doesn't work with <joined-subclass>, it works only with <subclass>

what about

query = from eg.DomesticCat cat where cat.name= ?
...

Cat myCat = (Cat)query.list().get(x);

* Thanks for your response, but my real situation is following construct. Topic <one-ton-many> Action <joined-subclass> Request, Reminder, Adjudication.

* Now, I would like to get all Topics having Actions (abstract class) where
Request.status = 'PENDING' or Reminder.number = 'LAST'.

* My query is now ...
List lList = HibernateUtil.currentSession().find(
"select distinct stu from Topic as top " +
"join top.actions act " +
// NOW, IF HAVE ALL ACTIONS BUT I WOULD LIKE
// TO GO ON WITH SOMETHING LIKE THIS ...
"where Request.status = ? "
"and Reminder.number = ?",
new Object[] {new String("PENDING"),
new String("LAST")},
new Typ[] {Hibernate.STRING, Hibernate.STRING}
);

* But this doesn't work. Therefore my question again: How can I query attributes of subclass using <joined-subclass>? In my situation how I query "where Request.status = ? and Reminder.number = ?" ...

casting in HQL is not possible today.

* Therefore the only way I can query on attributes of subclasses is to use nativ SQL queries see?

* To use one-to-one relations instead of joined sublasses or subclasses, what do you think about that approach?

my opinion is that your domain model does not have to depend on query problem, so if you're sure this domain model is the best way to deal with your business, don't change it and use sql queries

Now if a one to one is also ok for your domain model, go for it as HQL is very powerfull