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--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 emp t WHERE hire_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 emp t WHERE hire_date BETWEEN TO_DATE (‘20060501‘, ‘yyyymmdd‘) AND TO_DATE (‘20060731‘, ‘yyyymmdd‘) ORDER BY create_time DESC, emp_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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原文地址：http://www.cnblogs.com/tingbogiu/p/5703529.html
