题解 | #有取消订单记录的司机平均评分#

select driver_id,round(avg(grade),1)
from tb_get_car_order o left join tb_get_car_record r using(order_id)
where driver_id in(select driver_id from tb_get_car_order where fare is null)
group by  driver_id
union 
SELECT "总体"as driver_id,round(avg(grade),1)
from tb_get_car_order o left join tb_get_car_record r using(order_id)
where driver_id in(select driver_id from tb_get_car_order where fare is null)