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 t.dept_no, t.dept_name, count(1) as cnt from (select s.emp_no,s.salary,d.dept_no,dd.dept_name from salaries s left join dept_emp d on s.emp_no = d.emp_no left JOIN departments dd on dd.dept_no = d.dept_no) t group by t.dept_no, t.dept_name order by t.dept_no asc