题解 | #查找在职员工自入职以来的薪水涨幅情况#

select b.emp_no,(b.salary-a.salary) growth from (select e.emp_no,s.salary from employees e left join salaries s on e.emp_no=s.emp_no and e.hire_date=s.from_date) a join (select e.emp_no,s.salary from employees e left join salaries s on e.emp_no=s.emp_no where s.to_date='9999-01-01') b on a.emp_no=b.emp_no order by growth