ORACLE分页查询SQL语法

--1:无ORDER BY排序的写法。(效率最高) ­
--(经过测试，此方法成本最低，只嵌套一层，速度最快！即使查询的数据量再大，也几乎不受影响，速度依然！) ­
SELECT * ­
  from (Select ROWNUM AS ROWNO, T.* ­
           from k_task T ­
          where Flight_date between to_date('20060501', 'yyyymmdd') and ­
                to_date('20060731', 'yyyymmdd') ­
            AND ROWNUM <= 20) TABLE_ALIAS ­
WHERE TABLE_ALIAS.ROWNO >= 10; ­
­
--2:有ORDER BY排序的写法。(效率最高) ­
--(经过测试，此方法随着查询范围的扩大，速度也会越来越慢哦！) ­
SELECT * ­
  from (SELECT TT.*, ROWNUM AS ROWNO ­
           from (Select t.* ­
                    from k_task T ­
                   where flight_date between to_date('20060501', 'yyyymmdd') and ­
                         to_date('20060531', 'yyyymmdd') ­
                   ORDER BY FACT_UP_TIME, flight_no) TT ­
          WHERE ROWNUM <= 20) TABLE_ALIAS ­
where TABLE_ALIAS.rowno >= 10; ­
­
--3:无ORDER BY排序的写法。(建议使用方法1代替) ­
--(此方法随着查询数据量的扩张，速度会越来越慢哦！) ­
SELECT * ­
  from (Select ROWNUM AS ROWNO, T.* ­