#先找出有取消订单记录的司机 with a as( select distinct driver_id from tb_get_car_record tr join tb_get_car_order too on tr.order_id = too.order_id where date(too.order_time) between '2021-10-01' and '2021-10-31' and fare is null) #主查询——求每个司机 select IFNULL(driver_id, "总体") as driver_id, round(avg(grade),1) as avg_grade from tb_get_car_record tr join tb_get_car_order too on tr.order_id = too.order_id where driver_id in (select * from a) and grade is not null group by driver_id WITH ROLLUP
学到了一种求总体