--1:無ORDER BY排序的寫法。 (效率最高) ­
--(經過測試，此方法成本最低，只嵌套一層，速度最快！即使查詢的資料量再大，也幾乎不受影響，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排序的寫法。 (效率最高) ­
--(經過測試，此方法隨著查詢範圍的擴大，速度也會越來越慢哦！) ­
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:無ORDER BY排序的寫法。 (建議使用方法1代替) ­
--(此方法隨著查詢資料量的擴張，速度會越來越慢喔！) ­
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排序的寫法.(建議使用方法2代替) ­
--(此方法隨著查詢範圍的擴大，速度會越來越慢哦！) ­
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另類語法。 (有ORDER BY寫法） ­
--(文法風格與傳統的SQL文法不同，不方便閱讀與理解，為規範與統一標準，不建議使用。) ­
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另類語法。 (無ORDER BY寫法） ­
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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