select
        sftb.staff_id,
        sftb.staff_name,
        concat(round(sltb.dock_salary / sltb.normal_salary * 100,1),'%') as dock_ratio
from
        staff_tb as sftb
left join 
        salary_tb as sltb
on 
        sftb.staff_id = sltb.staff_id
where 
        sftb.department = 'dep1'
order by 
        dock_ratio desc