Question

I have a hql query like this:

  return (long)Session.CreateQuery (" select count(*) " +
                                      "   from Files p " +
                                      "   join fetch p.Application a " +
                                      "  where a.Name = :AppName")
                        .SetParameter("AppName", application)                            
                        .UniqueResult();

Hibernate creates sql query like this:

   select field1, field2, field3, count(*)

That’s why it cannot be executed.

Why select count(*) makes hibernate to list all fields and how to prevent it?

Thanks

Answer 1

In my opinion, the problem comes with the use of ‘FETCH‘, which is normally used to get the dependencies of a given entity from the database. So Hibernate queries the fields of Application to create the objects.

If you only want to count the files associated to an application, change ‘JOIN FETCH‘ for ‘INNER JOIN‘ (or simply ‘JOIN‘). The only queried field should be count(*) then.