code: def get_query(self):
          
  
          assert self.model is not None, (
              "'{}' should include a `model` attribute, or override the `get_query()` method."
                  .format(self.__class__.__name__)
          )
  
          return self.request.dbsession.query(self.model)
docs: Get the list of items for this view.
          You may want to override this if you need to provide different query  depending on the incoming request.
          (Eg. return a list of items that is specific to the user)
  
          :return: ``sqlalchemy.orm.query.Query``