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 st.post , round(avg(timestampdiff(minute,at.first_clockin,at.last_clockin))/60,3) as work_hours from staff_tb as st left outer join attendent_tb as at on st.staff_id=at.staff_id group by st.post order by work_hours desc
