Putting nulls in hibernate 2 query

[John Landon]

Hi,
I am trying to do something like this:

String query = "from Buyer br where br.type= :type;
resList = hsess.createQuery(query).setParameter("type", null).list();  

the persistent object buyer DOES allow nulls. And there ARE nulls in the database. But when I try to run it it gives me:
"inconsistent datatypes: expected NUMBER got BINARY"

So how do I do what I want to do?