在SQL Server中查找并删除重复的朋友连接

我需要一个脚本来查找有多个朋友连接的会员，因此它不会在网站上多次显示他们的友谊。在SQL Server中查找并删除重复的朋友连接

的MemberConnection表如下：

+----------------------+------------+----------------+ 
| MemberConnectionID | MemberID | ConnMemberID | 
+----------------------+------------+----------------+ 
| 25     | 33  | 43    | 
| 26     | 43  | 33    | 
| 27     | 13  | 143   | 
| 28     | 143  | 13    | 
| 29     | 33  | 43    | 
+----------------------+------------+----------------+

正如你可以看到行25和29是相同的，我需要找到这些重复这样他们就可以被删除。

如何为此编写脚本？

任何人都可以提供的帮助将不胜感激。

提前

neojakey

来源

2013-02-01 neojakey

你想同时删除它吗？ –

是否要删除一行或两行？另外，你有什么尝试？ – LukeHennerley

你如何在'MemberID，ConnMemberID'上创建'UNIQUE'约束？ – Kermit

，如果你要离开一个连接试试这个：

使用此功能选择连接：

;WITH CTE 
AS 
(
    SELECT 
     MemberConnectionID, 
     ROW_NUMBER() OVER (PARTITION BY MemberID, ConnMemberID ORDER BY MemberConnectionID) RN 
    FROM MemberConnection 
) 
SELECT 
     MemberConnectionID 
FROM CTE 
WHERE RN > 1

或使用该从表中删除：

;WITH CTE 
AS 
(
    SELECT 
     ROW_NUMBER() OVER (PARTITION BY MemberID, ConnMemberID ORDER BY MemberConnectionID) RN 
    FROM MemberConnection 
) 
DELETE 
FROM CTE 
WHERE RN > 1

来源

2013-02-01 15:56:56

非常感谢这个脚本工作出色.. +1为你.. – neojakey

非常感谢你可以这样做：

SELECT * FROM 
(SELECT MemberID,ConnMemberID ,count(MemberID,ConnMemberID) as c FROM MemberConnection group by MemberID,ConnMemberID) x 
WHERE x.c >1

这将显示所有的重复行。

来源

2013-02-01 15:56:25

以此为测试：

DECLARE @Table AS TABLE 
    (
     MemberConnectionID INT , 
     MemberID INT , 
     ConMemberID INT 
    ) 

INSERT INTO @Table 
     SELECT 1 , 
       2 , 
       3 
INSERT INTO @Table 
     SELECT 2 , 
       3 , 
       4 
INSERT INTO @Table 
     SELECT 3 , 
       2 , 
       3

成员连接

SELECT COUNT(MemberConnectionID) AS Occurence , 
      MemberID , 
      ConMemberID 
FROM  @Table 
GROUP BY MemberID , 
      ConMemberID

DELETE语句的选择occurence

DELETE FROM @Table 
FROM @Table t 
     INNER JOIN (SELECT MemberID , 
          ConMemberID 
        FROM (SELECT COUNT(MemberConnectionID) AS Occurence , 
             MemberID , 
             ConMemberID 
           FROM  @Table 
           GROUP BY MemberID , 
             ConMemberID 
          ) t2 
        WHERE t2.Occurence > 1 
        ) t3 ON t3.MemberID = T.MemberID 
          AND t3.ConMemberID = t.ConMemberID

来源

2013-02-01 16:06:25 LukeHennerley

我总是用这个小查询（更改以满足您的表）。

Delete MemberConnection 
from MemberConnection 
join 
(select max(MemberConnectionId)as CountIt, MemberId, ConnMemberId 
    from #MemberConnection 
    group by MemberId, ConnMemberId 
    having count(1) > 1 
) as derived 
on MemberConnection.MemberId = derived.MemberId 
and MemberConnection.ConnMemberId = derived.ConnMemberId 
and CountIt > MemberConnectionId

来源

2013-02-01 16:07:05 SandSnark

在SQL Server中查找并删除重复的朋友连接

回答

相关问题