Oracle分页总汇

Oracle分页总汇

 

select * from

(select a.*,rownum row_num from

(select * from mytable t order by t.id desc) a

where rownum<=10

) b where b.row_num >= 1 order by u_age desc;    

 

select * from 

 

(select a.*,rownum row_num from 

 

(select * from mytable t order by t.id desc) a

 

) b where b.row_num between 1 and 10 

 

.1.根据ROWID来分

 

select * from t_xiaoxi where rowid in(select rid from (select rownum rn,rid from(select rowid rid,cid from 

 

t_xiaoxi  order by cid desc) where rownum<10000) where rn>9980) order by cid desc;

执行时间0.03秒

 

2.按分析函数来分

 

select * from (select t.*,row_number() over(order by cid desc) rk from t_xiaoxi t) where rk<10000 and rk>9980;

执行时间1.01秒

 

3.按ROWNUM来分

 

select * from(select t.*,rownum rn from(select * from t_xiaoxi order by cid desc) t where rownum<10000) where rn>9980;

执行时间0.1秒

其中t_xiaoxi为表名称，cid为表的关键字段，取按CID降序排序后的第9981-9999条记录，t_xiaoxi表有70000多条记录

个人感觉1的效率最好，3次之，2最差

 

--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！) 

--4:有ORDER BY排序的写法.(建议使用方法2代替)

 

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; 

 

--(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; 

 

--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;