题解 | #考试分数(二)#
考试分数(二)
http://www.nowcoder.com/practice/f456dedf88a64f169aadd648491a27c1
1、求解平均分
select b.job,avg(b.score) as pp from grade b group by b.job
2、查找所有的id,job,以及分数
select a.id ,a.job,a.score from grade a
3、左连接+筛选(高于平均值)
select a.id ,a.job,a.score from grade a left join (select b.job,avg(b.score) as pp from grade b group by b.job ) as c on a.job = c.job where a.score > c.pp
4、升序
select a.id ,a.job,a.score from grade a left join (select b.job,avg(b.score) as pp from grade b group by b.job ) as c on a.job = c.job where a.score > c.pp order by a.id