net.sf.hibernate.QueryException: in expected:

I am getting the above exception when i am accessing the data when composite keys are there. Anyone can u give give an idea how to fetch data when composite keys are there

Have a read of the manual:
http://www.hibernate.org/hib_docs/reference/en/html/mapping.html#mapping-declaration-compositeid

and

http://www.hibernate.org/hib_docs/reference/en/html/components.html#components-compositeid

In summary, depending on your approach; you must instantiate an instance of the persistent class itself or the key class and populate its identifier properties before you can load() the persistent state associated with a composite key.