题解 | 统计各个部门的工资记录数
统计各个部门的工资记录数
https://www.nowcoder.com/practice/6a62b6c0a7324350a6d9959fa7c21db3
select
d.dept_no ,
d.dept_name ,
count(s.salary) as sum
from departments d
join dept_emp de on d.dept_no = de.dept_no
join salaries s on de.emp_no = s.emp_no
group by d.dept_no ,d.dept_name
order by d.dept_no
