视图创建请教~

[leon4567001]

创建一个视图，查询的时候发现有两条数据都是学生A的，其中一个字段S_ID老的记录值为1，新纪录S_ID=2，如何写视图只查询到S_ID=2的那条记录？

[minitoy]

按s_id做个逆序,取序号为一得.

[minitoy]

select * from
(select t.*,row_number()over(partition by t.stu_num order by t.s_id desc) rn from view t) where rn=1;
或者用not exists
select * from view t where not exists(select 1 from view s
where t.stu_num=s.stu_num and t.s_id<s.stu_num)

[gelyon]

根据时间来降序排序，取最新的那条记录

[真的不知道取什么名]

select * from 
(select t.*,row_number() over(partition by stuid order by S_ID desc) rn
 from viewname)
where rn=1

[leon4567001]

OK，搞定，谢谢大家~