09查询各科成绩前三名的记录
--查询各科成绩前三名的记录selecta.Cid,a.Sid,a.score,count(b.score)+1from(select*fromSCgroupbyCid,Sid,score)aleftjoin(select*fromSCgroupbyCid,Sid,score)bona.Cid=b.Cidanda.score<b.scoregroupbya.Cid,a.Sid,a.scorehavingcount(b.score)<3orderbya.Cidasc,a.scoredesc;
来自:数据库基础-数据库数据类型