--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') ) table_alias ; --2:有ORD
--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_
--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_DAT
已知有两种方法效率上貌似第一种更优: 1. select * from( select t1.*, rownum n from (select * from cm_log order by oper_time desc) t1 where rownum <= 5000) b where b.n >5; 注:rownum 和 order by 同时出现在where 语句中时除非 order by 的主键否则都是按先执行rownum后排序,所以这里用了先子查询排序在执行rownum条件, 还有个用
1. select * from ( select t.*, rownum RN from TABLE_NAME t ) where RN > 0 and RN <= 15 2. select * from ( select t.*, rownum RN from TABLE_NAME t ) where RN between 1 and 15
Oracle分页(limit方式的运用) Oracle不支持类似于 MySQL 中的 limit. 但你还是可以rownum来限制返回的结果集的行数. 第一种 select * from a_matrix_navigation_map where rowid not in(select rowid from a_matrix_navigation_map where rownum<=0) and rownum<=10 第二种: SELECT * FROM ( SELECT A.*, rownu
作者: kent鹏 转载请注明出处: http://www.cnblogs.com/xieyupeng/p/7289451.html --oracle分页(Pageing Query) select * from (select rownum r,e1.* from (select * from emp order by sal) e1 ) ; SQL SQL> --查询工资比SCOTT高的员工信息 SQL> --1. SCOTT的工资 SQL> select sal from emp
撰写过程:网上搜集测试了好多的Oracle分页存储过程代码,经整理后终于通过测试,特分享给大家 测试步骤:1.运行创建包命令;2.运行创建存储过程命令;3.运行调用分页存储过程语句 测试环境:windows2003+Oracle11g+PLSQL Developer --1.创建包命令 create or replace package mypackage as type cursor_page is ref cursor; Procedure myprocdure(