etl.py 文件源码

def get_last_departure_time(self):
        query = """ SELECT MAX(departuretime) FROM connection """

        with connect(self.connection_string) as con:
            con.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT)
            with con.cursor() as cur:
                cur.execute(query)
                result = cur.fetchone()
                if result is not None:
                    last_departure_time = result[0]
                    return last_departure_time
                return None