--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.* ­
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; ­
­
­
--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; ­
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