这样的事情：

Something like this:

WHILE ((SELECT TOP (1) [Stuid] FROM [MyTable] GROUP BY [Stuid] HAVING Count(*)>1) > 0)
BEGIN
	DELETE TOP (1) FROM MyTable
	WHERE ((Stuid) In (SELECT [Stuid] FROM [MyTable] As Tmp GROUP BY [Stuid] HAVING Count(*)>1 ))
END  

您将需要添加一个唯一的列到你的桌子，这样你就可以区分同一行的不同副本：

You're going to need to add a unique column to your table, so that you can distinguish between different copies of the same row:

ALTER TABLE YourTable
ADD TempRowNumber int IDENTITY(1, 1) NOT NULL;

然后你需要找到并删除重复的行。假设您只关心 Stuid 列：

Then you need to find and delete the duplicate rows. Assuming you only care about the Stuid column:

DELETE
FROM
    T1
FROM
    YourTable As T1
WHERE
    Exists
    (
        SELECT 1
        FROM YourTable As T2
        WHERE T2.Stuid = T1.Stuid
        And T2.TempRowNumber < T1.TempRowNumber
    )
;

如有必要，您可以删除临时唯一列，并添加适当的唯一约束：

If necessary, you can then drop the temporary unique column, and add a proper unique constraint:

ALTER TABLE YourTable
DROP COLUMN TempRowNumber;
GO
ALTER TABLE YourTable
WITH CHECK
ADD CONSTRAINT UX_YourTable_Stuid UNIQUE (Stuid);
GO

检查出来：https://support.microsoft.com/en-us/kb/139444 [ ^ ]