linq to sql checking for null -


my database field int_parentid consist of null value . how check null in linq query . not working 

  return _db.categories.where(m => m.int_parentid==null);

have mapped int_parentid database field int? type (e.g. <column name="int_parentid" type="system.int32" dbtype="int" canbenull="true" />)? if yes, both:

return _db.categories.where(m => m.int_parentid == null);

and

return _db.categories.where(m => m.int_parentid.hasvalue);

should work.


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