code: def _execute_simple_query(self, query):
          
          self._logger.info(u'Execute simple query: [{}]'.format(query))
  
          # All of the statements in the query are sent here in a single message
          self.connection.write(messages.Query(query))
  
          # The first response could be a number of things:
          #   ErrorResponse: Something went wrong on the server.
          #   EmptyQueryResponse: The query being executed is empty.
          #   RowDescription: This is the "normal" case when executing a query.
          #                   It marks the start of the results.
          #   CommandComplete: This occurs when executing DDL/transactions.
          self._message = self.connection.read_message()
          if isinstance(self._message, messages.ErrorResponse):
              raise errors.QueryError.from_error_response(self._message, query)
          elif isinstance(self._message, messages.RowDescription):
              self.description = [Column(fd, self.unicode_error) for fd in self._message.fields]
              self._message = self.connection.read_message()
              if isinstance(self._message, messages.ErrorResponse):
                  raise errors.QueryError.from_error_response(self._message, query)
docs: Send the query to the server using the simple query protocol.
          Return True if this query contained no SQL (e.g. the string "--comment")