有一个表格
id ord_id
1 10
2 10
3 20
4 20
5 20
现在想生成一个新表格，多一个列new_id，要求是：显示一样的ord_id里取最小的id
id new_id ord_id
1 1 10
2 1 10
3 3 20
4 3 20
5 3 20
------解决方案--------------------
- SQL code
--> 测试数据：[t1]if object_id('[t1]') is not null drop table [t1]create table [t1]([id] int,[ord_id] int)insert [t1]select 1,10 union allselect 2,10 union allselect 3,20 union allselect 4,20 union allselect 5,20select id,(select min(id) from t1 a where a.[ord_id]=b.[ord_id]) as [newid] ,[ord_id] from t1 bgroup by [ord_id],id/*id newid ord_id1 1 102 1 103 3 204 3 205 3 20*/