2016-08-16 Oracle分页功能实现

来源：互联网发布：汉字域名编辑：程序博客网时间：2024/04/29 17:03

每天积累一点点，感觉自己又进步了

--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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