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

先子查询筛选出部门领导

再用not in筛选出非部门领导