select a1.emp_no,a2.emp_no,s1.salary,s2.salary
from (select * from dept_emp where emp_no not in (select emp_no from dept_manager)) as a1
join (select * from dept_emp where emp_no in (select emp_no from dept_manager)) as a2
on a1.dept_no = a2.dept_no
join (select * from salaries where emp_no not in (select emp_no from dept_manager)) as s1
on a1.emp_no = s1.emp_no
join (select * from salaries where emp_no in (select emp_no from dept_manager)) as s2
on a2.emp_no = s2.emp_no
where s1.salary > s2.salary;