帮我看看这条select语句
select count(paper_deptid) as papercount,paper_deptid,dept_name
from papers,dept
where papers.paper_deptid=dept.dept_id
group by papers.paper_deptid

提示错误：列 'dept.dept_name' 在选择列表中无效，因为该列既不包含在聚合函数中，也不包含在 GROUP BY 子句中。
SQL
[解决办法]
Group by 没有包含 dept_name
[解决办法]
select count(paper_deptid) as papercount,paper_deptid,dept_name
from papers,dept
where papers.paper_deptid=dept.dept_id
group by papers.paper_deptid ,papercount,dept_name