题解 | #统计各岗位员工平均工作时长#

select post,
       avg(timestampdiff(minute,first_clockin,last_clockin)/60) as work_hours
from staff_tb a
right join attendent_tb b on a.staff_id=b.staff_id
where first_clockin is not null and last_clockin is not null
group by post
order by work_hours desc