补充另一种做法： select distinct emp_no, (max(salary)-min(salary)) growth from salaries where emp_no in ( select emp_no from salaries where to_date='9999-01-01' ) and salary in ( select salary from employees e join salaries s on e.emp_no =s.emp_no where hire_date=from_date or to_date='9999-01-01' ) group by emp_no order by growth