删除重复列

DELETE FROM abc
      WHERE ROWID IN (SELECT r
                        FROM (SELECT t.ROWID r,
                                     ROW_NUMBER( )
                                     OVER ( PARTITION BY empno, ename, job
                                            ORDER BY empno, ename, job )
                                        id
                                FROM abc t)
                       WHERE id <> 1);


create   table abc2  as select empno,ename,job from abc group by empno,ename,job;