DataGrid和存储过程结合的分页，只读取当前页数据

时间：2005-05-19 来源：bandt

用到了DataGrid和存储过程，直接从数据库查询当前页数据，避免了DataGrid固有的返回全部记录的缺陷。
还有一个不完善的地方：需要执行两次数据库查询。把查询记录总数也集成到存储过程中就完美了。

<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Data" %>

<html>
<head><title>Paging.aspx</title></head>
<body>
<form Runat="Server">

<asp:DataGrid Runat="Server"
ID="dgrdProducts"
showheader="false"
AllowPaging="True"
AllowCustomPaging="True"
PageSize="10"
OnPageIndexChanged="dgrdProducts_PageIndexChanged"
PagerStyle-Mode="NumericPages"
AlternatingItemStyle-BackColor="#eeaaee"
HeaderStyle-BackColor="#aaFFdd"
Font-Size="10pt"
Font-Name="Verdana"
CellSpacing="0"
CellPadding="3"
GridLines="Both"
BorderWidth="1"
BorderColor="black"
PagerStyle-HorizontalAlign="Right">
<AlternatingItemStyle BackColor="#EEEEEE"></AlternatingItemStyle>
</asp:datagrid>
<asp:linkbutton id="btnFirst" onclick="PagerButtonClick" runat="server" Font-Name="verdana" Font-size="8pt" ForeColor="navy" CommandArgument="0"></asp:linkbutton> 
<asp:linkbutton id="btnPrev" onclick="PagerButtonClick" runat="server" Font-Name="verdana" Font-size="8pt" ForeColor="navy" CommandArgument="prev"></asp:linkbutton> 
<asp:linkbutton id="btnNext" onclick="PagerButtonClick" runat="server" Font-Name="verdana" Font-size="8pt" ForeColor="navy" CommandArgument="next"></asp:linkbutton> 
<asp:linkbutton id="btnLast" onclick="PagerButtonClick" runat="server" Font-Name="verdana" Font-size="8pt" ForeColor="navy" CommandArgument="last"></asp:linkbutton>
</form>
</html>
下面是存储过程：
CREATE PROCEDURE OrdersPaged
(
@PageIndex int,
@PageSize int
)
AS
BEGIN
DECLARE @PageLowerBound int
DECLARE @PageUpperBound int
DECLARE @RowsToReturn int

-- First set the rowcount
SET @RowsToReturn = @PageSize * (@PageIndex + 1)
SET ROWCOUNT @RowsToReturn

-- Set the page bounds
SET @PageLowerBound = @PageSize * @PageIndex
SET @PageUpperBound = @PageLowerBound + @PageSize + 1

-- Create a temp table to store the select results
CREATE TABLE #PageIndex
(
IndexId int IDENTITY (1, 1) NOT NULL,
OrderID int
)

-- Insert into the temp table
INSERT INTO #PageIndex (OrderID)
SELECT
    OrderID
FROM
    Orders
ORDER BY
    OrderID DESC

-- Return total count
--SELECT COUNT(OrderID) FROM Orders

-- Return paged results
SELECT
    O.*
FROM
    Orders O,
    #PageIndex PageIndex
WHERE
    O.OrderID = PageIndex.OrderID AND
    PageIndex.IndexID > @PageLowerBound AND
    PageIndex.IndexID < @PageUpperBound
ORDER BY
    PageIndex.IndexID

END
GO
参考资料：
《编写高性能 Web 应用程序的 10 个技巧》
《ASP.NET揭秘》