oracle 分页

 

1、常用分页：    只有通过伪列ROWNUM来实现       越到后面记录查询越慢！对于千万数据很慢！

SELECT *
  FROM (SELECT T.*, ROWNUM AS R
          FROM (SELECT * FROM TABLENAME) T
         WHERE ROWNUM <= 10)
 WHERE R >= 1

 

2、高效分页：

SELECT *
  FROM (SELECT T.*, ROW_NUMBER() OVER(ORDER BY N_COUNT DESC) R
          FROM T_NEWS T) T
 WHERE R BETWEEN 4 AND 6

--通用语法： 解析函数() over(partition by 字段 order by 字段)
-- partition by 分组
-- order by  排序