GridView自定义分页的四种存储过程

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。

复制代码代码如下:

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

复制代码代码如下:

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

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

<html xmlns=”http://www.w3.org/1999/xhtml” >

<head runat=”server”>

<title>Paging</title>

</head>

<body>

<form id=”form1″ runat=”server”>

<div>

<asp:LinkButton id=”lbtnFirst” runat=”server” CommandName=”First” OnCommand=”lbtnPage_Command”>|<</asp:LinkButton>

<asp:LinkButton id=”lbtnPrevious” runat=”server” CommandName=”Previous” OnCommand=”lbtnPage_Command”><<</asp:LinkButton>

<asp:Label id=”lblMessage” runat=”server” />

<asp:LinkButton id=”lbtnNext” runat=”server” CommandName=”Next” OnCommand=”lbtnPage_Command”>>></asp:LinkButton>

<asp:LinkButton id=”lbtnLast” runat=”server” CommandName=”Last” OnCommand=”lbtnPage_Command”>>|</asp:LinkButton>

转到第<asp:DropDownList ID=”dropPage” runat=”server” AutoPostBack=”True” OnSelectedIndexChanged=”dropPage_SelectedIndexChanged”></asp:DropDownList>页

<asp:GridView ID=”GridView1″ runat=”server” AutoGenerateColumns=”False” DataKeyNames=”ProductID” DataSourceID=”SqlDataSource1″>

<Columns>

<asp:BoundField DataField=”ProductID” HeaderText=”ProductID” InsertVisible=”False” ReadOnly=”True” />

<asp:BoundField DataField=”ProductName” HeaderText=”ProductName” />

<asp:BoundField DataField=”SupplierID” HeaderText=”SupplierID” />

<asp:BoundField DataField=”CategoryID” HeaderText=”CategoryID” />

<asp:BoundField DataField=”QuantityPerUnit” HeaderText=”QuantityPerUnit” />

<asp:BoundField DataField=”UnitPrice” HeaderText=”UnitPrice” />

<asp:BoundField DataField=”UnitsInStock” HeaderText=”UnitsInStock” />

<asp:BoundField DataField=”UnitsOnOrder” HeaderText=”UnitsOnOrder” />

<asp:BoundField DataField=”ReorderLevel” HeaderText=”ReorderLevel” />

<asp:CheckBoxField DataField=”Discontinued” HeaderText=”Discontinued” />

</Columns>

</asp:GridView>

<asp:SqlDataSource ID=”SqlDataSource1″ runat=”server” ConnectionString=”Data Source=.\sqlexpress;Initial Catalog=Northwind;Integrated Security=True” ProviderName=”System.Data.SqlClient” SelectCommand=”GetProductsByPage” SelectCommandType=”StoredProcedure” OnSelecting=”SqlDataSource1_Selecting” OnSelected=”SqlDataSource1_Selected”>

<SelectParameters>

<asp:Parameter Name=”PageNumber” Type=”Int32″ />

<asp:Parameter Name=”PageSize” Type=”Int32″ />

</SelectParameters>

</asp:SqlDataSource>

</div>

</form>

</body>

</html>

复制代码代码如下:

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

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

复制代码代码如下:

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;

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