请教下大佬我这个写法有什么问题呢？ select city , driver_id ,round(g,1),round(g/c,1),round(m/c,3) from( SELECT city, driver_id, count(a.order_time), sum(mileage) m, avg(grade) g, dense_rank () over ( PARTITION BY city ORDER BY avg(grade) DESC ) rk, count(distinct DATE_FORMAT(order_time,'%Y%m%d')) c FROM tb_get_car_order a LEFT JOIN tb_get_car_record b ON a.order_id = b.order_id GROUP BY city, driver_id) a where rk = 1 group by city , driver_id