题解 | #汇总各个部门当前员工的title类型的分配数目#

select
emp.dept_no,ts.dept_name,t.title,count(t.title) as countno
from
departments ts 
join dept_emp emp on ts.dept_no=emp.dept_no
join titles t on emp.emp_no=t.emp_no
group by emp.dept_no,ts.dept_name,t.title order by emp.dept_no,t.title