题解 | #汇总各个部门当前员工的title类型的分配数目#

select de.dept_no

    ,ds.dept_name

    ,ts.title

    ,count(de.emp_no)over(partition by de.dept_no,ts.title) as count

from dept_emp de

join titles ts using(emp_no)

join departments ds using(dept_no)

where  de.to_date="9999-01-01"

and ts.to_date="9999-01-01"