题解 | 统计员工薪资扣除比例

select
    t1.staff_id,
    t1.staff_name,
    concat(round(sum(dock_salary) / sum(normal_salary)*100,1),"%") as dock_ratio
from
    (
        select
            staff_id,
            staff_name
        from
            staff_tb
        where
            department = "dep1"
    ) t1
    left join salary_tb using (staff_id)
group by
    t1.staff_id,
    t1.staff_name
order by dock_ratio desc