题解 | #汇总各个部门当前员工的title类型的分配数目#
汇总各个部门当前员工的title类型的分配数目
https://www.nowcoder.com/practice/4bcb6a7d3e39423291d2f7bdbbff87f8
select d.dept_no,d.dept_name,t.title,count(t.title) count from departments d inner join dept_emp de on d.dept_no=de.dept_no inner join titles t on de.emp_no=t.emp_no where t.to_date='9999-01-01' and de.to_date='9999-01-01' group by d.dept_no,t.title order by d.dept_no,t.title
考察表连接,以及分组依据可以有多个值