postgres.py 文件源码

def query_cursor(self, q, lazy_fetch=False, commit=True):
        """Execute a query and yield a cursor.

        All execution performed by the Postgres object uses this method.

        Args:
            q (str): SQL query
            lazy_fetch (bool): whether to use a server-side cursor (lazily fetches results).
        """
        self.cursors_opened += 1

        if self.verbose:
            logging.debug(q)

        if self.debug:
            empty_cursor = Bunch()
            empty_cursor.fetchmany = lambda size: []
            empty_cursor.fetchall = lambda: []
            yield empty_cursor
            return

        cursor_name = 'server_side_{}'.format(self.cursors_opened) if lazy_fetch else None
        with self.connection.cursor(cursor_name, cursor_factory=RealDictCursor) as cursor:
            cursor.execute(q)
            yield cursor

        if commit:
            self.commit()