oracle数据去重

 数据去重，仅供参考

--方法一
DELETE
  FROM SCOTT.EMP T
 WHERE T.ROWID IN (SELECT ROWID
                     FROM (SELECT T.EMPNO,
                                  ROW_NUMBER() OVER(PARTITION BY T.EMPNO ORDER BY T.EMPNO) RID
                             FROM SCOTT.EMP T)
                    WHERE RID > 1);
 --方法二                   
 DELETE
   FROM SCOTT.EMP T
  WHERE T.ROWID NOT IN
        (SELECT MAX(ROWID) FROM SCOTT.EMP T1 WHERE T.EMPNO = T1.EMPNO);