题解 | 统计快递运输时长
统计快递运输时长
https://www.nowcoder.com/practice/bb4196936f15424dbabe76a501186d91
-- 按快递种类聚合前各快递的运输时长(关联查询，时间函数)
with
t1 as (
select
exp_type,
timestampdiff (second, out_time, in_time) / 3600 ys_time
from
express_tb et
left join exp_action_tb ea on et.exp_number = ea.exp_number
)
-- 计算每种类型快递的平均运输时长（分组查询、聚合函数、排序）
select
exp_type,
round(avg(ys_time), 1) time
from
t1
group by
exp_type
order by
time
查看13道真题和解析
