In topic 925219 I asked about a query on subtype attributes using HQL and got a great answer. This is with a base class of Event with subclasses AlarmEvent and ManageEvent.

In HQL the query is something like:

select event from Event event, AlarmEvent alarm, ManageEvent manage
where (event = alarm and alarm.acknowledged = false) or
(event = manage and manage.confirmed = false)

Is it possible to accomplish the same type of query using the Criteria API?

I've searched thru the forum and haven't seen anything like this and
have looked at the examples and some of the test case code too.
The MultiTableTest shows lots of HQL but nothing much using the API.

No, the query above results in a table join. HQL does not support typecasts.