自用题解

select de.dept_no,a.emp_no,s.salary
from 
(select emp_no
from employees 
where emp_no not in (select emp_no
from dept_manager)
) a 
inner join dept_emp de on a.emp_no=de.emp_no
inner join salaries s on a.emp_no=s.emp_no
where s.to_date='9999-01-01'