题解 | 统计各岗位员工平均工作时长
统计各岗位员工平均工作时长
https://www.nowcoder.com/practice/b7220791a95a4cd092801069aefa1cae
select
# s.staff_id,
post,
# first_clockin,
# last_clockin,
# avg(TIMESTAMPDIFF(minute, first_clockin,last_clockin)/60) as work_hours
avg((UNIX_TIMESTAMP(last_clockin ) - UNIX_TIMESTAMP(first_clockin)) / 3600 ) as work_hours
from staff_tb s
join attendent_tb a on s.staff_id = a.staff_id
where first_clockin is not null and last_clockin is not null
group by post
order by work_hours desc
两种方法：
（1）
TIMESTAMPDIFF(minute, first_clockin, last_clockin)/60
（2）
(UNIX_TIMESTAMP(last_clockin ) - UNIX_TIMESTAMP(first_clockin)) / 3600
