DECLARE @TB TABLE(NAME VARCHAR(100));
INSERT INTO @TB VALUES ('Red'),('Red'),('Green'),('Blue'),('White'),('White')
--**Delete by Rank**
;WITH CTE AS(SELECT NAME,DENSE_RANK() OVER (PARTITION BY NAME ORDER BY NEWID()) ID FROM @TB)
DELETE FROM CTE WHERE ID>1
SELECT NAME FROM @TB;
--**Delete by Row Number** 
;WITH CTE AS(SELECT NAME,ROW_NUMBER() OVER (PARTITION BY NAME ORDER BY NAME) ID FROM @TB)
DELETE FROM CTE WHERE ID>1;
SELECT NAME FROM @TB;

不使用CTE和ROW_NUMBER()，您可以通过使用group by和MAX函数删除记录，这里是一个例子

DELETE
FROM MyDuplicateTable
WHERE ID NOT IN
(
SELECT MAX(ID)
FROM MyDuplicateTable
GROUP BY DuplicateColumn1, DuplicateColumn2, DuplicateColumn3)

在尝试了上面建议的解决方案后，它适用于小型中型表。 我可以为非常大的表提出这个解决方案。因为它在迭代中运行。

Drop all dependency views of the LargeSourceTable you can find the dependecies by using sql managment studio, right click on the table and click "View Dependencies" Rename the table: sp_rename 'LargeSourceTable', 'LargeSourceTable_Temp'; GO Create the LargeSourceTable again, but now, add a primary key with all the columns that define the duplications add WITH (IGNORE_DUP_KEY = ON) For example: CREATE TABLE [dbo].[LargeSourceTable] ( ID int IDENTITY(1,1), [CreateDate] DATETIME CONSTRAINT [DF_LargeSourceTable_CreateDate] DEFAULT (getdate()) NOT NULL, [Column1] CHAR (36) NOT NULL, [Column2] NVARCHAR (100) NOT NULL, [Column3] CHAR (36) NOT NULL, PRIMARY KEY (Column1, Column2) WITH (IGNORE_DUP_KEY = ON) ); GO Create again the views that you dropped in the first place for the new created table Now, Run the following sql script, you will see the results in 1,000,000 rows per page, you can change the row number per page to see the results more often. Note, that I set the IDENTITY_INSERT on and off because one the columns contains auto incremental id, which I'm also copying

设置IDENTITY_INSERT LargeSourceTable ON 声明@PageNumber为INT， @RowspPage为INT 声明@TotalRows为INT 声明@dt varchar(19) SET @PageNumber = 0 SET @RowspPage = 1000000 select @TotalRows = count (*) from LargeSourceTable_TEMP

While ((@PageNumber - 1) * @RowspPage < @TotalRows )
Begin
    begin transaction tran_inner
        ; with cte as
        (
            SELECT * FROM LargeSourceTable_TEMP ORDER BY ID
            OFFSET ((@PageNumber) * @RowspPage) ROWS
            FETCH NEXT @RowspPage ROWS ONLY
        )

        INSERT INTO LargeSourceTable 
        (
             ID                     
            ,[CreateDate]       
            ,[Column1]   
            ,[Column2] 
            ,[Column3]       
        )       
        select 
             ID                     
            ,[CreateDate]       
            ,[Column1]   
            ,[Column2] 
            ,[Column3]       
        from cte

    commit transaction tran_inner

    PRINT 'Page: ' + convert(varchar(10), @PageNumber)
    PRINT 'Transfered: ' + convert(varchar(20), @PageNumber * @RowspPage)
    PRINT 'Of: ' + convert(varchar(20), @TotalRows)

    SELECT @dt = convert(varchar(19), getdate(), 121)
    RAISERROR('Inserted on: %s', 0, 1, @dt) WITH NOWAIT
    SET @PageNumber = @PageNumber + 1
End

SET IDENTITY_INSERT LargeSourceTable OFF

试着使用:

SELECT linkorder
    ,Row_Number() OVER (
        PARTITION BY linkorder ORDER BY linkorder DESC
        ) AS RowNum
FROM u_links

我喜欢CTE和ROW_NUMBER，因为两者结合起来可以让我们看到哪些行被删除(或更新)，因此只需更改DELETE FROM CTE…SELECT * FROM CTE:

WITH CTE AS(
   SELECT [col1], [col2], [col3], [col4], [col5], [col6], [col7],
       RN = ROW_NUMBER()OVER(PARTITION BY col1 ORDER BY col1)
   FROM dbo.Table1
)
DELETE FROM CTE WHERE RN > 1

DEMO(结果不同;我想这是由于你的打字错误。

COL1    COL2    COL3    COL4    COL5    COL6    COL7
john    1        1       1       1       1       1
sally   2        2       2       2       2       2

由于使用了PARTITION by col1，这个例子通过一个列col1来确定重复项。如果你想包含多个列，只需将它们添加到PARTITION BY:

ROW_NUMBER()OVER(PARTITION BY Col1, Col2, ... ORDER BY OrderColumn)

微软有一个关于如何删除重复文件的非常简洁的指南。查看http://support.microsoft.com/kb/139444

简而言之，当你只有几行要删除时，下面是删除重复项的最简单方法:

SET rowcount 1;
DELETE FROM t1 WHERE myprimarykey=1;

Myprimarykey是行标识符。

我将rowcount设置为1，因为我只有两行复制。如果我复制了3行，那么我就会将rowcount设置为2，这样它就会删除它看到的前两行，只在表t1中留下一行。