Using NHibernate Criteria with Join to get row count

Google for lot of places for using Criteria object having joins and get rowcount either by using Projections.RowCount or CriteriaTransformer.TransformToRowCount. Now I have started looking into NHibernate source code which does also provides with examples of how to use it. So the example is as follows :-

  public void TransformToRowCountTest()
  {
   ISession s = OpenSession();
   ITransaction t = s.BeginTransaction();

   ICriteria crit = s.CreateCriteria(typeof(Student));
   ICriteria subCriterium = crit.CreateCriteria("PreferredCourse");
   subCriterium.Add(Property.ForName("CourseCode").Eq("MCSD"));


   ICriteria countCriteria = CriteriaTransformer.TransformToRowCount(crit);

   int rowCount = (int)countCriteria.UniqueResult();

   t.Rollback();
   s.Close();
  }

This does the job of counting number of students who are enrolled for a course with code "MCSD" The real danger is not that computers will begin to think like men, but that men will begin to think like computers. ~Sydney J. Harris