常用关系数据库分页SQL都是不相同的,不过大同小异
下面是Oracle分页简单事例图片以及代码:
1、普通查询:
select * from table_Name t order by active_count desc;
2、查询第一条记录:
select *
from (select * from table_Name order by active_count desc)
where rownum = 1;
3、查询前3条:类似Sqlserver中的TOP 3
select *
from (select * from table_Name order by active_count desc)
where rownum <= 3;
4、查询第2至第3条记录:
select *
from (select t.*, rownum as no
from (select * from table_Name order by active_count desc) t)
where no between 2 and 3
5、在TOP3条记录的基础上查询第2至第3条记录:
select *
from (select t.*, rownum as no
from (select * from table_Name order by active_count desc) t where rownum <= 3 )
where no between 2 and 3
6、查询第2条以后的记录:
select *
from (select t.*, rownum as no
from (select * from table_Name order by active_count desc) t)
where no >=2
解释:
rownum 是在已产生数据的基础上伪生成的编号,所以 使用rownum 必须在已有数据的基础上,因此Oracle分页才加入了多个子查询。