转自:

**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(200))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,'猫猫小屋'),(1,'a'),(6,'b1'),(7,'C1'),(4,'d000'),(10,'maomao365.com')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 gotruncate table A drop table A go