Oracle, DB2 及 MySQL 分页查询写法

现在在WEB 应用中使用分页技术越来越普遍了，其中利用数据库查询分页是一种效率比较高的方法，

下面列出了Oracle, DB2 及 MySQL 分页查询写法。

一：Oracle
select * from (select rownum,name from table where rownum <=endIndex )
where rownum > startIndex

二：DB2
DB2分页查询
SELECT * FROM (Select 字段1,字段2,字段3,rownumber() over(ORDER BY 排序用的列名 ASC) AS rn from 表名) AS a1 WHERE a1.rn BETWEEN 10 AND 20

以上表示提取第10到20的纪录

select * from (select rownumber() over(order by id asc ) as rowid from table where rowid <=endIndex ) AS a1
where a1.rowid > startIndex

三：MySQL

select * from table limit start,pageNum

SELECT EVENTID , EVENTNAME , CREATETIME , ELAPSEDTIME , REPEATCOUNT , MESSAGE , LOCALINSTANCEID , STATUS , MEMO FROM(SELECT rownumber() OVER (ORDER BY CREATETIME ASC) AS rowid FROM MS_EVENT WHERE rowid <=20) as a1 WHERE a1.rowid >10

SELECT * FROM (SELECT EVENTID , EVENTNAME , CREATETIME , ELAPSEDTIME , REPEATCOUNT , MESSAGE , LOCALINSTANCEID , STATUS , MEMO,
ROWNUMBER() OVER (ORDER BY CREATETIME ASC) AS rn FROM MS_EVENT) AS a1 WHERE a1.rn BETWEEN 10 and 20

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1. 标准的rownum分页查询使用方法：

select *
from (select c.*, rownum rn from content c)
where rn >= 1
and rn <= 5

2. 但是如果, 加上order by addtime 排序则数据显示不正确

select *
from (select c.*, rownum rn from content c order by addtime)
where rn >= 1
and rn <= 5

解决方法，再加一层查询，则可以解决，

select *
from (select rownum rn, t.*
from (select title, addtime from content order by addtime desc) t)
where rn >= 1
and rn <= 5

如果要考虑到效率的问题，上面的还可以优化成（主要两者区别）

select *
from (select rownum rn, t.*
from (select title, addtime from content order by addtime desc) t
where rownum <= 10)
where rn >= 3

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如果查询结果需要分页,从效率上讲,下面的效率应该比较高(粉红色表示需要根据实际情况填充的地方)

三类数据库中进行分页查询的高效率方法(目前来看):

Oracle: SELECT * FROM (
SELECT MY_TABLE.*,ROWNUM AS MY_ROWNUM FROM (
/** 括号里写实际的需要查询的SQL语句**/
) AS MYTABLE WHERE ROWNUM <=200/**这里是一页中的最后一条记录**/
/) WHERE MY_ROWNUM>=10 /**这里是一页中的第一条记录**/

SQLServer: SELECT * FROM (
SELECT TOP 页面容量 * FROM (
SELECT TOP 页面容量*当前页码 * FROM
表 WHERE 条件 ORDER BY 字段A ASC
)AS TEMPTABLE1 ORDER BY 字段A DESC
) AS TEMPTABLE2 ORDER BY 字段A ASC

MYSQL: SELECT 语句 LIMIT 页面的第一条记录-1,页面容量