code: def objects(self, json_result=False):
          
          self.rows_num = 0
          query = self.query()
          if not isinstance(query, (orm.Result, list, dict)):
              query = do_(query)
          for record in query:
              self.rows_num += 1
              r = self.object(record, json_result)
              self._cal_sum(record)
              yield r
          total = self._render_sum(True)
          if total:
              yield total
docs: Return a generator of all processed data, it just like render
          but it'll not return a table or json format data but just
          data. And the data will be processed by fields_convert_map if passed.