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,sum(1) sum from departments d join dept_emp de using(dept_no) join salaries s using(emp_no) group by d.dept_no order by d.dept_no