Question

我有以下模式的学区，Tehsil，学校代码和学校名称：

District Tehsil  SchCode        SchName
A          AA    11111111       AA1
A          AA    11111111       AA2
A          AA    11111111       AA3
B          BB    22222222       BB1
B          BB    22222222       BB2
B          BB    22222222       BB3

我想检查SchCode中的重复是否将相同的SchCode分配给具有相同或不同SchName的任何其他学校。

请为此建议SQL Server查询。我正在使用SQL Server 2008 Exp

Answer 1

您可以加入按该列分组的相关子查询：

SELECT t1.District, t1.Tehsil, t1.SchCode, t1.SchName
FROM dbo.TableName t1
INNER JOIN (SELECT SchCode 
            FROM dbo.TableName 
            GROUP BY SchCode HAVING COUNT(*) > 1) dup
ON t1.SchCode = dup.SchCode

Sql-fiddle返回所有行，因为它们都是另一行的重复。

如果您只是想知道某条记录是否有重复内容，则可以使用此查询：

SELECT t1.District, t1.Tehsil, t1.SchCode, t1.SchName, 
       hasDuplicate = CASE WHEN dup.SchCode IS NULL THEN 'no' ELSE 'yes' END
FROM dbo.TableName t1
LEFT OUTER JOIN (SELECT SchCode 
                 FROM dbo.TableName 
                 GROUP BY SchCode HAVING COUNT(*) > 1) dup
ON t1.SchCode = dup.SchCode

Sql-fiddle已修改数据以获得非重复数据。

Answer 2

试试这个

;WITH cte AS 
(SELECT   Row_number() OVER (partition BY schcode ORDER BY schname) id,* 
 FROM     tablename ) 
SELECT * 
FROM   tablename a 
JOIN   (SELECT   id,schcode ,count(1)
        FROM     cte 
        GROUP BY id,schcode 
        HAVING   Count(1) > 1)) B 
ON     a.schcode = b.schcode

或

SELECT * 
FROM   tablename a 
JOIN   (SELECT   schname,schcode ,count(1)
        FROM     tablename 
        GROUP BY schname,schcode 
        HAVING   Count(1) > 1)) B 
ON     a.schcode = b.schcode

检查重复数据的重复

2 个答案: