题解 | #有取消订单记录的司机平均评分#

select driver_id, round(avg(grade), 1) as avg_grade from tb_get_car_order where driver_id in ( select driver_id from tb_get_car_order where start_time is null ) group by driver_id

union

select '总体' as driver_id, round(avg(grade), 1) as avg_grade from tb_get_car_order where driver_id in ( select driver_id from tb_get_car_order where start_time is null )

order by driver_id ASC