select c.dept_no,d.emp_no,c.maxSalary from
(select p.dept_no,max(p.salary) as maxSalary
from
(select dept_no,a.emp_no,salary
from dept_emp a join salaries b
on a.emp_no=b.emp_no
order by salary desc)p
group by dept_no
)c
left join
(select dept_no,a.emp_no,salary
from dept_emp a join salaries b
on a.emp_no=b.emp_no)d
on c.dept_no=d.dept_no
where c.maxSalary=d.salary
order by c.dept_no