题解 | #SQL26 汇总各个部门当前员工的title类型的分配数目#

select dp.dept_no, ds.dept_name, tt.title, count(dp.emp_no) from dept_emp dp 
left join titles tt on dp.emp_no = tt.emp_no
left join departments ds on ds.dept_no = dp.dept_no
group by dp.dept_no, tt.title
order by dp.dept_no