转自:http://www.maomao365.com/?p=4942
下文主要讲述：重复数据只获取一条的方法
row_number函数在数据库中的功能是为每一行 按照一定的规则生成一个编号，
我们常常利用这一属性，对表进行分页操作，下文我们将讲述采用 row_number函数删除表中重复数据行
/*建表*/
create table A(keyId int,info varchar(20))
go
/*生成数据*/
insert into A(keyId,info)values
(1,'a'),(2,'b'),(3,'C'),(4,'d'),(5,'e'),
(1,'a'),(21,'b1'),(31,'C1'),(4,'d'),(51,'e'),
(1,'a'),(6,'b1'),(7,'C1'),(4,'d000'),(10,'e')
go /*删除 keyId重复数据 中的另外几条*/
delete [A2] from
(select row_number() over (Partition By keyId order by keyId) as keyId2,* from A ) as [A2]
where [A2].keyId2 >1 /*
/*删除 所有列都重复数据 中的另外几条*/
delete [A2] from
(select row_number() over (Partition By keyId,info order by keyId) as keyId2,* from A ) as [A2]
where [A2].keyId2 >1
*/ /*展示删除后的数据*/ select * from A
go truncate table A
drop table A
go