oracle 分页总结

分页的几种写法：
--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 (
[真正的查询]    
//[]里面放我们需要写的查询语句
         AND ROWNUM <=  '每页条数'*‘第几页’
) TABLE_ALIAS
WHERE TABLE_ALIAS.ROWNO >= ‘每页条数’*(‘第几页’-1)+1;

例子：
SELECT ROWNO,MCOM_COUPON_ID,MCOM_COUPON_TITLE,DISCOUNT_RATE,POINTS,IS_BESTUNION_USER
  FROM (

select ROWNUM AS ROWNO,t.*,me.*  //这里我们需要的是两个表的数据所以，最上面的select 后面就需要给出实际的表所对应的字段
  from mcom_coupon t, MCOM_ENTERPRISES me
where (t.ent_addr like '%春熙路%' or t.mcom_coupon_title like '%春熙路%')
   and me.mcom_enterprises_sid = t.MCOM_ENTERPRISES_SID
  
   and ROWNUM <= '每页条数'*‘第几页’) TABLE_ALIAS
WHERE TABLE_ALIAS.ROWNO >= ‘每页条数’*(‘第几页’-1)+1;
//第1页，给的值就是1


--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.*
           from k_task T
          where Flight_date between to_date('20060501', 'yyyymmdd') and
                to_date('20060731', 'yyyymmdd')) TABLE_ALIAS
WHERE TABLE_ALIAS.ROWNO <= 20
   AND TABLE_ALIAS.ROWNO >= 10;
--TABLE_ALIAS.ROWNO  between 10 and 100;




--4:有ORDER BY排序的写法.(建议使用方法2代替)
--(此方法随着查询范围的扩大，速度会越来越慢哦！)
SELECT *
  FROM (SELECT TT.*, ROWNUM AS ROWNO
           FROM (Select *
                    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) TABLE_ALIAS
where TABLE_ALIAS.rowno BETWEEN 10 AND 20;

例如：
SELECT    *    FROM
(
SELECT A. * , ROWNUM RN
FROM (

Select ROWNUM AS ROWNO, T.*
           from mcom_coupon T
          where T.mcom_coupon_indu_id='27' ) A
        
)
WHERE RN BETWEEN ‘每页几条’*(‘第几页’-1)+1 AND ‘每页几条’*‘第几页’


--5另类语法。(有ORDER BY写法）
--(语法风格与传统的SQL语法不同，不方便阅读与理解，为规范与统一标准，不推荐使用。)
With partdata as(
  SELECT ROWNUM AS ROWNO, TT.*  FROM (Select *
                  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)
    Select * from partdata where rowno >= 10;

--6另类语法 。(无ORDER BY写法）
With partdata as(
  Select ROWNUM AS ROWNO, T.*
    From K_task T
   where Flight_date between to_date('20060501', 'yyyymmdd') and
         To_date('20060531', 'yyyymmdd')
     AND ROWNUM <= 20)
    Select * from partdata where Rowno >= 10;