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 de.dept_no, dept_name, count(*) as `sum` from dept_emp de join departments d on de.dept_no=d.dept_no join salaries s on de.emp_no=s.emp_no group by de.dept_no order by dept_no;