题解 SQ3
查找当前薪水详情以及部门编号dept_no
http://www.nowcoder.com/practice/c63c5b54d86e4c6d880e4834bfd70c3b
-- select job|avg(1.0*score) from grade group by job ;
select job , round((1.0*sum(score)/count(id) ),3) as a from grade group by job order by a desc ;