题解 | #有取消订单记录的司机平均评分#

select 
    driver_id 
    ,round(avg(grade) ,1) avg_grade
from 
    tb_get_car_order   
where 
    driver_id 
in (
        select 
    driver_id 
from 
    tb_get_car_order 
where 
    start_time is null 
and 
 substring(order_time,1,7)='2021-10'
    )
group by 
    driver_id
union all 
 select 
    '总体' as driver_id
    ,round(avg(grade),1) avg_grade
from 
    tb_get_car_order   
where 
    driver_id 
in (
        select 
    driver_id 
from 
    tb_get_car_order 
where 
    start_time is null 
and 
 substring(order_time,1,7)='2021-10'
    )