Question

我正在编写此查询以显示从外部源自动填充的表中的一组名称：

select MAX(UN_ID) as [ID] , MAX(UN_Name) from UnavailableNames group by (UN_Name)

我有很多名称重复，所以我使用“分组依据”

我想在执行此选择查询后立即删除所有重复项。（删除字段UN_Name可用两次，保留一次）

有什么办法吗？

Answer 1

这样的事情应该有效：

WITH CTE AS 
(
    SELECT rn = ROW_NUMBER() 
                OVER( 
                  PARTITION BY UN_Name
                  ORDER BY UN_ID ASC), * 
    FROM dbo.UnavailableNames
) 
DELETE FROM cte 
WHERE  rn > 1

您基本上在每个组中分配一个增加的“行号”，它们共享相同的“un_name”。

然后你只删除所有“行号”大于1的行，并保留所有首先出现的行。

Answer 2

With CTE As
(
Select uid,ROW_NUMBER() OVER( PARTITION BY uname order by uid) as rownum
From yourTable

)

Delete 
From yourTable
where uid in (select uid from CTE where rownum> 1 )

删除字段从同一个表中重复

2 个答案: