题解 | #有取消订单记录的司机平均评分#

with t1
    as(
    #1、2021年10月有过取消订单记录的司机的订单记录
    select 
    t1.driver_id,
    t2.grade
    from tb_get_car_order t1
    left join tb_get_car_order t2
    on t1.driver_id=t2.driver_id
    where t1.start_time is null  
    )
#2、获取有取消订单的司机的平均评分
select 
    driver_id,
    round(avg(grade),1) `avg_grade`
from t1
group by t1.driver_id
union 
#3、总体评分
select
    '总体' ,
    round(avg(grade) over(),1)
from t1
#一定要放在最后面哦
order by driver_id