删除重复数据

WITH C1

AS

(

SELECT [MachineName]

      ,[EnvironmentID]

      ,[MachineFunction]

      ,[InsertDate]

      ,[APFlag]

      ,ROW_NUMBER() OVER(PARTITION BY [MachineName] ORDER BY [InsertDate]) AS RowNum

  FROM [BingAdsMachines].[dbo].[MachineHistoryDistinct]

  WHERE InsertDate > '2013-07-31'

  )

DELETE *

FROM C1

WHERE RowNum > 1

笨方法：

INSERT INTO TEMP FROM  SELECT DISTINCT * from TABLE

TRUNCATE TABLE [TABLE]

INSERT INTO TABLE FROM SELECT * FROM TEMP