I am trying to get hibernate to generate the following sql query:

select count (*) from (select distinct msisdn, productid from PURCHASES)


I've managed to generate the sub-query

select distinct msisdn, productid from PURCHASES with the following code:

criteria.setProjection(Projections.distinct(Projections.projectionList()
.add(Projections.property("msisdn"))
.add(Projections.property("productId"))))


I've been looking at DetachedCriteria. Is this possible?

I'm using hibernate 3.0.