oracle分页查询

 

分页查询

数据库表结构及记录如下：

1.根据rowid来分：

16:31:48 SQL> select * from passvehicleinfo p where rowid in ( select rid from (select rownum rn,rid from (select p.rowid rid,p.passvehicleid from passvehicleinfo p order by p.passvehicleid desc) view1 where rownum<10000) view2 where rn >9980) order by p.passvehicleid asc;

2.按分析函数来分

17:02:42 SQL> select * from (select p.*,row_number() over (order by p.passvehicleid desc ) rk from passvehicleinfo p) where rk>9980 and rk<10000;

3.按rownum来分

17:07:38 SQL> select * from (select view1.*,rownum rn from (select p.* from passvehicleinfo p order by p.passvehicleid desc) view1 where rownum<10000) view2 where rn>9980;

下面最主要介绍第三种：按rownum来分

 

1. rownum 分页

SELECT * FROM emp;

2. 显示rownum[oracle分配的]

SELECT e.*, ROWNUM rn FROM (SELECT * FROM emp) e;

rn相当于Oracle分配的行的ID号

 

3.挑选出6—10条记录

先查出1-10条记录

SELECT e.*, ROWNUM rn FROM (SELECT * FROM emp) e WHERE ROWNUM <= 10;

如果后面加上rownum>=6是不行的，

4. 然后查出6-10条记录

SELECT * FROM (SELECT e.*, ROWNUM rn FROM (SELECT * FROM emp) e WHERE ROWNUM <= 10) WHERE rn >= 6;

5. 几个查询变化

a. 指定查询列，只需要修改最里层的子查询

只查询雇员的编号和工资

SELECT * FROM (SELECT e.*, ROWNUM rn FROM (SELECT ename, sal FROM emp)

e WHERE ROWNUM <= 10) WHERE rn >= 6;

b. 排序查询，只需要修改最里层的子查询

工资排序后查询6-10条数据

SELECT * FROM (SELECT e.*, ROWNUM rn FROM (SELECT ename, sal FROM emp ORDER

by sal) e WHERE ROWNUM <= 10) WHERE rn >= 6;