题解 | #查找在职员工自入职以来的薪水涨幅情况#

select t1.emp_no,(t1.salary-t2.salary) as growth
from (
    select s.emp_no,s.salary
    from salaries s
    where s.to_date='9999-01-01'
)t1
join (
    select s.emp_no,s.salary
    from salaries s
    join employees e on e.emp_no=s.emp_no
    where s.from_date=e.hire_date
)t2
on t1.emp_no=t2.emp_no
order by growth