**row_number函數在數據庫中的功能是為每一行 按照一定的規則生成一個編號，

我們常常利用這一屬性，對表進行分頁操作，

下文我們將講述采用 row_number函數刪除表中重復數據行**

/*建表*/
create table A(keyId int,info varchar(200))
go 
/*生成數據*/
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,‘貓貓小屋‘),
(1,‘a‘),(6,‘b1‘),(7,‘C1‘),(4,‘d000‘),(10,‘maomao365.com‘)
go

/*刪除 keyId重復數據 中的另外幾條*/
delete [A2] from 
(select row_number() over (Partition By keyId order by keyId) as keyId2,* from A ) as [A2]
where [A2].keyId2  >1 

/*
/*刪除 所有列都重復數據 中的另外幾條*/
delete [A2] from 
(select row_number() over (Partition By keyId,info order by keyId) as keyId2,* from A ) as [A2]
where [A2].keyId2  >1 
 */

/*展示刪除後的數據*/

select * from A 
go

truncate table A 
drop table A 
go
 

MSSQL sql server 2005/2008 row_number()函數應用之–刪除表中重