Paging GridView with ROW_NUMBER()

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Introduction

Searching on the web, I found a lot of useful articles about this new feature of SQL Server 2005 and among them I mention the Jason Witty�s article - that was a starting point for me. We have been waiting for a long time for this new feature of SQL Server 2005. I don�t want to compare this new kind of ASP .NET paging with the well-known paging using temporary table, RowCount method or Cursor method, used with SQL Server 2000, but rather how simple is to paging a GridView in this way and to customize it. I don't use the built-in mechanism for paging of GridView web control.

I wrote this sample, because I needed to add custom paging for a grid view that allows easily changing the page size and go directly to a page number without passing throughout each page, one by one. In the past, I already used this kind of paging with data grid. To change it from datagrid to gridview I cut and paste the code and the job is done. Code behind is really a rudimentary one and is very easily to understand.

Code

In the Size button click event, we set the current page number and the page size and the we bind the GridView to display the data:

PageNum = 1;
PageSize = Convert.ToInt16(PageSizeTxt.Text);
BindGridView();

In the Go button event click, where we go to a page number:

        if (GoToPageTxt.Text != "")
        {
            int maxPage  = Convert.ToInt32(TotalPages.Text);
            int goToPage = Convert.ToInt32(GoToPageTxt.Text);

            if (goToPage <= maxPage)
            {
                PageNum = goToPage;
                BindGridView();
            }
        }

Here is the GridView HTML code:

<asp:GridView  ID="GridView1" runat="server" AutoGenerateColumns="False" >
       <Columns>
              <asp:BoundField DataField="RowNumber" HeaderText="RowNumber" />
              <asp:BoundField DataField="Name" HeaderText="Name" />
              <asp:BoundField DataField="SalesYTD" HeaderText="SalesYTD" />
              <asp:BoundField DataField="PostalCode" HeaderText="PostalCode" />
       </Columns>               
</asp:GridView>

I built the stored procedure with a SQL Server 2005 Books Online example. As you can see, it returns the ROW_NUMBER for the salespeople in AdventureWorks database, based on the year-to-date sales. My intention is not to explain how ROW_NUMBER() works, because it's already done in SQL Server 2005 Books Online or in many articles on the web, but how to pass the parameters to a stored procedure for customizing paging using ROW_NUMBER(). I just included the Microsoft query into my stored procedure and the paging works very well. Finally, the query returns the total number of records to calculate how many pages we can display. The stored procedure script is shown below:

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

CREATE PROCEDURE [dbo].[sp_GridView_RowNumber]
(
    @PageNum int,
    @PageSize int,
    @TotalRowsNum int output
)
AS

BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from

    -- interfering with SELECT statements.

    SET NOCOUNT ON;

    -- Use ROW_NUMBER function

    WITH Salespeople_AdventureWorks As
    (
        SELECT 'RowNumber' = ROW_NUMBER() OVER(ORDER BY SalesYTD DESC), 
               'Name' = c.FirstName + ' ' + c.LastName, s.SalesYTD, a.PostalCode
        FROM Sales.SalesPerson s JOIN Person.Contact c on s.SalesPersonID = c.ContactID
        JOIN Person.Address a ON a.AddressID = c.ContactID
        WHERE ((TerritoryID IS NOT NULL) AND (s.SalesYTD <> 0))
    )

    -- Query result

    SELECT * 
    FROM Salespeople_AdventureWorks
    WHERE RowNumber BETWEEN (@PageNum - 1) * @PageSize + 1 AND @PageNum * @PageSize             
    ORDER BY SalesYTD DESC

    -- Returns total records number

    SELECT @TotalRowsNum = count(*) 
    FROM Sales.SalesPerson s JOIN Person.Contact c on s.SalesPersonID = c.ContactID
    JOIN Person.Address a ON a.AddressID = c.ContactID
    WHERE ((TerritoryID IS NOT NULL) AND (s.SalesYTD <> 0))
END

The source code includes the solution in Visual Studio 2005 and the script for the stored procedure. You have to change your connection string in the code to run the sample.