GridView自定义分页的四种存储过程

首先要说说为什么不用GridView的默认的分页功能，GridView控件并非真正知道如何获得一个新页面，它只是请求绑定的数据源控件返回适合规定页面的行，分页最终是由数据源控件完成。

1. 为什么不使用GridView的默认分页功能

首先要说说为什么不用GridView的默认的分页功能，GridView控件并非真正知道如何获得一个新页面，它只是请求绑定的数据源控件返回适合规定页面的行，分页最终是由数据源控件完成。当我们使用SqlDataSource或使用以上的代码处理分页时。每次这个页面被请求或者回发时，所有和这个SELECT语句匹配的记录都被读取并存储到一个内部的DataSet中，但只显示适合当前页面大小的记录数。也就是说有可能使用Select语句返回1000000条记录，而每次回发只显示10条记录。如果启用了SqlDataSource上的缓存，通过把EnableCaching设置为true，则情况会更好一些。在这种情况下，我们只须访问一次数据库服务器，整个数据集只加载一次，并在指定的期限内存储在ASP.NET缓存中。只要数据保持缓存状态，显示任何页面将无须再次访问数据库服务器。然而，可能有大量数据存储在内存中，换而言之，Web服务器的压力大大的增加了。因此，如果要使用SqlDataSource来获取较小的数据时，GridView内建的自动分页可能足够高效了，但对于大数据量来说是不合适的。

2. 分页的四种存储过程(分页+排序的版本请参考Blog里其他文章)

在大多数情况下我们使用存储过程来进行分页，今天有空总结了一下使用存储过程对GridView进行分页的4种写法(分别是使用Top关键字，临时表，临时表变量和SQL Server 2005 新加的Row_Number()函数)

后续的文章中还将涉及GridView控件使用ObjectDataSource自定义分页 + 排序，Repeater控件自定义分页 + 排序，有兴趣的朋友可以参考。
代码如下:

if exists(select 1 from sys.objects where name = 'GetProductsCount' and type = 'P') 
drop proc GetProductsCount 
go 
CREATE PROCEDURE GetProductsCount 
as 
select count(*) from products 
go 

--1.使用Top 
if exists(select 1 from sys.objects where name = 'GetProductsByPage' and type = 'P') 
drop proc GetProductsByPage 
go 
CREATE PROCEDURE GetProductsByPage 
@PageNumber int, 
@PageSize int 
AS 
declare @sql nvarchar(4000) 
set @sql = 'select top ' + Convert(varchar, @PageSize) 
+ ' * from products where productid not in (select top ' + Convert(varchar, (@PageNumber - 1) * @PageSize) + ' productid from products)' 
exec sp_executesql @sql 
go 

--exec GetProductsByPage 1, 10 
--exec GetProductsByPage 5, 10 

--2.使用临时表 
if exists(select 1 from sys.objects where name = 'GetProductsByPage' and type = 'P') 
drop proc GetProductsByPage 
go 
CREATE PROCEDURE GetProductsByPage 
@PageNumber int, 
@PageSize int 
AS 
-- 创建临时表 
CREATE TABLE #TempProducts 
( 
ID int IDENTITY PRIMARY KEY, 
ProductID int, 
ProductName varchar(40) , 
SupplierID int, 
CategoryID int, 
QuantityPerUnit nvarchar(20), 
UnitPrice money, 
UnitsInStock smallint, 
UnitsOnOrder smallint, 
ReorderLevel smallint, 
Discontinued bit 
) 
-- 填充临时表 
INSERT INTO #TempProducts 
(ProductID, ProductName, SupplierID, CategoryID, QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued) 
SELECT ProductID, ProductName, SupplierID, CategoryID, QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued 
FROM Products 

DECLARE @FromID int 
DECLARE @ToID int 
SET @FromID = ((@PageNumber - 1) * @PageSize) + 1 
SET @ToID = @PageNumber * @PageSize 

SELECT ProductID, ProductName, SupplierID, CategoryID, QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued 
FROM #TempProducts 
WHERE ID >= @FromID AND ID <= @ToID 
go 

--exec GetProductsByPage 1, 10 
--exec GetProductsByPage 5, 10 

--3.使用表变量 
/* 
为要分页的数据创建一个table变量,这个table变量里有一个作为主健的IDENTITY列.这样需要分页的每条记录在table变量里就和一个row index(通过IDENTITY列)关联起来了.一旦table变量产生,连接数据库表的SELECT语句就被执行,获取需要的记录.SET ROWCOUNT用来限制放到table变量里的记录的数量. 
当SET ROWCOUNT的值指定为PageNumber * PageSize时,这个方法的效率取决于被请求的页数.对于比较前面的页来说– 比如开始几页的数据– 这种方法非常有效. 但是对接近尾部的页来说,这种方法的效率和默认分页时差不多 
*/ 
if exists(select 1 from sys.objects where name = 'GetProductsByPage' and type = 'P') 
drop proc GetProductsByPage 
go 
CREATE PROCEDURE GetProductsByPage 
@PageNumber int, 
@PageSize int 
AS 
DECLARE @TempProducts TABLE 
( 
ID int IDENTITY, 
productid int 
) 
DECLARE @maxRows int 
SET @maxRows = @PageNumber * @PageSize 
--在返回指定的行数之后停止处理查询 
SET ROWCOUNT @maxRows 

INSERT INTO @TempProducts (productid) 
SELECT productid 
FROM products 
ORDER BY productid 

SET ROWCOUNT @PageSize 

SELECT p.* 
FROM @TempProducts t INNER JOIN products p 
ON t.productid = p.productid 
WHERE ID > (@PageNumber - 1) * @PageSize 
SET ROWCOUNT 0 
GO 

--exec GetProductsByPage 1, 10 
--exec GetProductsByPage 5, 10 

--4.使用row_number函数 
--SQL Server 2005的新特性,它可以将记录根据一定的顺序排列,每条记录和一个等级相关 这个等级可以用来作为每条记录的row index. 
if exists(select 1 from sys.objects where name = 'GetProductsByPage' and type = 'P') 
drop proc GetProductsByPage 
go 
CREATE PROCEDURE GetProductsByPage 
@PageNumber int, 
@PageSize int 
AS 
select ProductID, ProductName, SupplierID, CategoryID, QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued 
from 
(select row_number() Over (order by productid) as row,ProductID, ProductName, SupplierID, CategoryID, QuantityPerUnit, UnitPrice, UnitsInStock, UnitsOnOrder, ReorderLevel, Discontinued 
from products) as ProductsWithRowNumber 
where row between (@PageNumber - 1) * @PageSize + 1 and @PageNumber * @PageSize 
go 

--exec GetProductsByPage 1, 10 
--exec GetProductsByPage 5, 10 
 
3. 在GridView中的应用 

 代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GridViewPaging.aspx.cs" Inherits="GridViewPaging" %> 

 

 
 
 
 
 
 
 
 
 
 代码如下:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GridViewPaging.aspx.cs" Inherits="GridViewPaging" %> 

 

 
 
 
 
 
 
 
 
 

 代码如下:

using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Data.SqlClient; 

public partial class GridViewPaging : System.Web.UI.Page 
{ 
//每页显示的最多记录的条数 
private int pageSize = 10; 
//当前页号 
private int currentPageNumber; 
//显示数据的总条数 
private static int rowCount; 
//总页数 
private static int pageCount; 

protected void Page_Load(object sender, EventArgs e) 
{ 
if (!IsPostBack) 
{ 
SqlConnection cn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString); 

SqlCommand cmd = new SqlCommand("GetProductsCount", cn); 
cmd.CommandType = CommandType.StoredProcedure; 
cn.Open(); 
rowCount = (int)cmd.ExecuteScalar(); 
cn.Close(); 
pageCount = (rowCount - 1) / pageSize + 1; 
currentPageNumber = 1; 
ViewState["currentPageNumber"] = currentPageNumber; 
lbtnPrevious.Enabled = false; 
lbtnFirst.Enabled = false; 

for (int i = 1; i <= pageCount; i++) 
{ 
dropPage.Items.Add(new ListItem(i.ToString(), i.ToString())); 
} 
dropPage.SelectedValue = dropPage.Items.FindByValue(currentPageNumber.ToString()).Value; 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 
} 

protected void SqlDataSource1_Selecting(object sender, SqlDataSourceSelectingEventArgs e) 
{ 
SqlDataSource1.SelectParameters["PageNumber"].DefaultValue = currentPageNumber.ToString(); 
SqlDataSource1.SelectParameters["PageSize"].DefaultValue = pageSize.ToString(); 
} 

protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e) 
{ 
lblMessage.Text = "共找到" + rowCount + "条记录, 当前第" + currentPageNumber + "/" + pageCount + "页"; 
} 

protected void lbtnPage_Command(object sender, CommandEventArgs e) 
{ 
switch (e.CommandName) 
{ 
case "First": 
currentPageNumber = 1; 
break; 
case "Previous": 
currentPageNumber = (int)ViewState["currentPageNumber"] - 1 > 1 ? (int)ViewState["currentPageNumber"] - 1 : 1; 
break; 
case "Next": 
currentPageNumber = (int)ViewState["currentPageNumber"] + 1 < pageCount ? (int)ViewState["currentPageNumber"] + 1 : pageCount; 
break; 
case "Last": 
currentPageNumber = pageCount; 
break; 
} 
dropPage.SelectedValue = dropPage.Items.FindByValue(currentPageNumber.ToString()).Value; 
ViewState["currentPageNumber"] = currentPageNumber; 
SetButton(currentPageNumber); 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 

private void SetButton(int currentPageNumber) 
{ 
lbtnFirst.Enabled = currentPageNumber != 1; 
lbtnPrevious.Enabled = currentPageNumber != 1; 
lbtnNext.Enabled = currentPageNumber != pageCount; 
lbtnLast.Enabled = currentPageNumber != pageCount; 
} 

protected void dropPage_SelectedIndexChanged(object sender, EventArgs e) 
{ 
currentPageNumber = int.Parse(dropPage.SelectedValue); 
ViewState["currentPageNumber"] = currentPageNumber; 
SetButton(currentPageNumber); 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 
} 
 
[/code] 
using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Data.SqlClient; 

public partial class GridViewPaging : System.Web.UI.Page 
{ 
//每页显示的最多记录的条数 
private int pageSize = 10; 
//当前页号 
private int currentPageNumber; 
//显示数据的总条数 
private static int rowCount; 
//总页数 
private static int pageCount; 

protected void Page_Load(object sender, EventArgs e) 
{ 
if (!IsPostBack) 
{ 
SqlConnection cn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["NorthwindConnectionString"].ConnectionString); 

SqlCommand cmd = new SqlCommand("GetProductsCount", cn); 
cmd.CommandType = CommandType.StoredProcedure; 
cn.Open(); 
rowCount = (int)cmd.ExecuteScalar(); 
cn.Close(); 
pageCount = (rowCount - 1) / pageSize + 1; 
currentPageNumber = 1; 
ViewState["currentPageNumber"] = currentPageNumber; 
lbtnPrevious.Enabled = false; 
lbtnFirst.Enabled = false; 

for (int i = 1; i <= pageCount; i++) 
{ 
dropPage.Items.Add(new ListItem(i.ToString(), i.ToString())); 
} 
dropPage.SelectedValue = dropPage.Items.FindByValue(currentPageNumber.ToString()).Value; 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 
} 

protected void SqlDataSource1_Selecting(object sender, SqlDataSourceSelectingEventArgs e) 
{ 
SqlDataSource1.SelectParameters["PageNumber"].DefaultValue = currentPageNumber.ToString(); 
SqlDataSource1.SelectParameters["PageSize"].DefaultValue = pageSize.ToString(); 
} 

protected void SqlDataSource1_Selected(object sender, SqlDataSourceStatusEventArgs e) 
{ 
lblMessage.Text = "共找到" + rowCount + "条记录, 当前第" + currentPageNumber + "/" + pageCount + "页"; 
} 

protected void lbtnPage_Command(object sender, CommandEventArgs e) 
{ 
switch (e.CommandName) 
{ 
case "First": 
currentPageNumber = 1; 
break; 
case "Previous": 
currentPageNumber = (int)ViewState["currentPageNumber"] - 1 > 1 ? (int)ViewState["currentPageNumber"] - 1 : 1; 
break; 
case "Next": 
currentPageNumber = (int)ViewState["currentPageNumber"] + 1 < pageCount ? (int)ViewState["currentPageNumber"] + 1 : pageCount; 
break; 
case "Last": 
currentPageNumber = pageCount; 
break; 
} 
dropPage.SelectedValue = dropPage.Items.FindByValue(currentPageNumber.ToString()).Value; 
ViewState["currentPageNumber"] = currentPageNumber; 
SetButton(currentPageNumber); 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 

private void SetButton(int currentPageNumber) 
{ 
lbtnFirst.Enabled = currentPageNumber != 1; 
lbtnPrevious.Enabled = currentPageNumber != 1; 
lbtnNext.Enabled = currentPageNumber != pageCount; 
lbtnLast.Enabled = currentPageNumber != pageCount; 
} 

protected void dropPage_SelectedIndexChanged(object sender, EventArgs e) 
{ 
currentPageNumber = int.Parse(dropPage.SelectedValue); 
ViewState["currentPageNumber"] = currentPageNumber; 
SetButton(currentPageNumber); 
SqlDataSource1.Select(DataSourceSelectArguments.Empty); 
} 
} 
[/code] 
4.分页效果图: