select 
d.dept_no as dept_no,
d.emp_no as emp_no ,
s.salary as maxSalary

from dept_emp d
inner join salaries s
on d.emp_no=s.emp_no

where s.salary in(
 select max(salary) from
 dept_emp d2 inner join
 salaries s2
 on
 d2.emp_no=s2.emp_no

where d2.dept_no=d.dept_no

 group by 
 d2.dept_no


)

order by  d.dept_no