1、 时间计算使用 timestampdiff(second,event_time,order_time)/60
才准确
2、注意要求的是工作日

select 
case when hour(event_time) >=7 and hour(event_time) <9 then "早高峰"
 when  hour(event_time) >=9 and hour(event_time) <17 then "工作时间"
 when  hour(event_time) >=17 and hour(event_time) <20 then "晚高峰"
 else "休息时间" end as period,
count(t.order_id) as get_car_num,
round(avg(timestampdiff(second,event_time,order_time)/60),1) as avg_wait_time ,
round(avg(timestampdiff(second,order_time,start_time)/60),1) as avg_dispatch_time
from tb_get_car_order t join tb_get_car_record t1 using(order_id)
where date_format(event_time,"%w") between 1 and 5
group by period
order by get_car_num