题解 | 统计加班员工占比

select
    department,
    concat(
        cast(
            round(
                count(
                    if(
                        timestampdiff(minute, first_clockin, last_clockin) > 570,
                        1,
                        null
                    )
                ) / count(*) * 100,
                1
            ) as CHAR
        ),
        "%"
    ) as ratio
from
    staff_tb st
    inner join attendent_tb at on st.staff_id = at.staff_id
group by
    department
order by
    ratio desc