随着数据库的发展,如今的数据库可以储存大量的数据,内存也是越来越大,但是无论您的内存多大,内存总是显得不够用,这时就要涉及到分页,下文中将为大家带来详细的数据库分页操作。
1.Oracle:
select * from ( select row_.*,rownum rownum_ from ( query_sql ) row_
where rownum =< max) where rownum_ >= min
2.sql Server:
select top @pagesize * from tablename where id not in
(select top @pagesize*(@page-1) id from tablename order by id) order by id
3.MysqL
select * from tablename limit position,counter
4.DB2
select * from (select *,rownumber() as ROW_NEXT from tablename)
where ROW_NEXT between min and max
分页方案一:(利用Not In和SELECT TOP分页)效率次之
语句形式:
SELECT TOP 10 * FROM TestTable
WHERE
(ID NOT IN (SELECT TOP 20 id FROM TestTable ORDERBY id)) ORDERBYID
SELECT TOP 页大小 * FROM TestTable
WHERE( ID NOT IN (SELECT TOP 每页大小*(待查询页数-1) id FROM 表
ORDERBY id)) ORDERBYID
思路:先查询出待查询页之前的全部条数的id,查询ID不在这些ID中的指定数量条数。
分页方案二:(利用ID大于多少和SELECT TOP分页)效率最高
语句形式:
SELECT TOP 10 * FROM TestTable
WHERE(ID>(SELECT MAX(id) FROM(SELECT TOP20 id FROM TestTable ORDERBYid)
AS T))ORDERBY ID
SELECT TOP 页大小* FROM TestTable
WHERE(ID>(SELECT MAX(id) FROM(SELECT TOP 每页大小*待查询页数-1 id FROM 表
ORDERBY id)AS T)) ORDERBY ID
思路:先获得待查询页的之前全部条数id,获得它们当中最大的ID号,以此最大ID号为标志,查找比这个ID号大的指定条数。
分页方案三:
SELECT TOP PageSize * FROM
(SELECT TOP nPage*PageSize * from YOURTABLE order by id) as a order by id desc
SELECT TOP 每页条数 * FROM
(SELECT TOP 待查询页*每页条数) * from YOURTABLE order by id)as a order by id desc
思路:先正排序查询出待查询页之前(包括当前页)的全部条数,然后将其倒排序,取指定条数。
方案四:
Select * FROM ( ============================================= |
方案五
//对数据进行重新排序然后分页
USE [Mail]
GO
/****** Object: StoredProcedure [dbo].[pro_MailReceiverPagelist] Script Date: 08/24/2012 15:08:13 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- ======================================================
-- Author: james.moriarty
-- Create date: 2012.05.22
-- ======================================================
ALTER PROCEDURE [dbo].[pro_MailReceiverPagelist]
@mailLogID INT=0,
@FIdx INT=1,
@EIdx INT=20,
@IsCount INT=1
AS
--with子查询只执行一次,将结果存储在用户临时表空间中,可以引用多次,增强性能
WITH TEMP
AS (SELECT Row_number() OVER(ORDER BY receiverID DESC) rowID,
receiverID,
receiverAddress
FROM [dbo].[MailReceiver]
WHERE mailLogID = @mailLogID)
SELECT *
FROM TEMP
WHERE rowID BETWEEN @FIdx AND @EIdx;
IF @IsCount = 0
RETURN 0;
DECLARE @rowcount INT
SELECT @rowcount = COUNT(*)
FROM [MailReceiver]
WHERE mailLogID = @mailLogID
PRINT @rowcount
RETURN @rowcount