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
http://www.nowcoder.com/practice/6a62b6c0a7324350a6d9959fa7c21db3
select departments.dept_no,departments.dept_name,count(salaries.emp_no) from departments left join dept_emp on departments.dept_no = dept_emp.dept_no right join salaries on dept_emp.emp_no = salaries.emp_no group by departments.dept_name order by departments.dept_no