1.找出含有重复项的id
2.保留各组第一条记录
DELETE FROM dbo.CJB WHERE OBJECT_ID IN ( SELECT t.OBJECT_ID oid FROM ( SELECT OBJECT_ID,ROW_NUMBER() OVER(PARTITION BY CJB.YJZH ORDER BY YJZH) xh FROM dbo.CJB WHERE YJZH IN ( SELECT YJZH FROM dbo.CJB GROUP BY YJZH HAVING COUNT(*)>1 ) )t WHERE t.xh<>1 )
