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.post, avg(timestampdiff(minute, a.first_clockin , a.last_clockin)/60) as work_hours from staff_tb s left join attendent_tb a USING (staff_id) group by post order by work_hours desc