select d.dept_no, dept_name, title, count
from departments as d
right outer join
(select dept_no, title, count(title) as count
from titles as t left outer join dept_emp as d
on t.emp_no = d.emp_no
group by dept_no,title) as dt
on d.dept_no = dt.dept_no
order by dept_no, title;

这一题最后的结果很迷，

题目中说了按照dept_no升序排序，

可是并没有说还要按照title升序排序，

最后结果可能会出现错误。

需要自己添加一个title排序才好。