CRUD Operations

CRUD operations using the PagerDataSource

This sample shows how to use the PagerDataSource to obtain, update and delete data from an ObjectDataSource. If a control that has full support for the new DataSourceControls like the GridView is bound to a PagerDataSource, the PagerDataSource will allow inserting, updating and deleting if the underlying data source of the PagerDataSource supports it.

What we want is to populate the GridView with items obtained from the ObjectDataSource and also let the users update or delete an item of the current page. We are using the PagerDataSource instead of the built-in pager of the GridView.

As you can see, the PagerDataSource can work with two way data binding without any problems, and with any control that needs to bind to a data source.

The source code for this page is shown after the live sample.

Product List

	id	name	description	price
Edit Delete	1	Product 1	Full description for product number 1	2
Edit Delete	2	Product 2	Full description for product number 2	4
Edit Delete	3	Product 3	Full description for product number 3	6
Edit Delete	4	Product 4	Full description for product number 4	8
Edit Delete	5	Product 5	Full description for product number 5	10
Edit Delete	6	Product 6	Full description for product number 6	12
Edit Delete	7	Product 7	Full description for product number 7	14
Edit Delete	8	Product 8	Full description for product number 8	16
Edit Delete	9	Product 9	Full description for product number 9	18
Edit Delete	10	Product 10	Full description for product number 10	20
Edit Delete	11	Product 11	Full description for product number 11	22
Edit Delete	12	Product 12	Full description for product number 12	24
Edit Delete	13	Product 13	Full description for product number 13	26
Edit Delete	14	Product 14	Full description for product number 14	28

Sample source code

The ASPX file for this sample is:.

                <%@
                Page Language="C#" MasterPageFile="~/DefaultMaster.master" AutoEventWireup="true" CodeFile="CRUD_operations.aspx.cs" Inherits="CRUD_operations" Title="CRUD Operations" %>

                    <%@ Register
                Assembly="PagerDataSource"
                Namespace="Manu.Web.UI.WebControls"
                TagPrefix="manu"
                %>

                <asp:Content 
                        ID="Content1" ContentPlaceHolderID="Content" Runat="Server">

<h2>Product List</h2>
                 
                    <manu:PagerDataSource
                ID="PagerDataSource1"
                runat="server"
            
                        DataSourceID="ObjectDataSource1"
                PageSize="14" 
                    
                            OnPageChanged="PagerDataSource_PageChanged">

                    </manu:PagerDataSource>

                    <asp:GridView 
                        ID="GridView1" runat="server" AutoGenerateColumns="False"
                
                    DataKeyNames="id" DataSourceID="PagerDataSource1" CssClass="gridview">

                        <Columns>

                            <asp:CommandField
                ShowDeleteButton="True"
                ShowEditButton="True"
                />

                            <asp:BoundField
                DataField="id"
                HeaderText="id"
                ReadOnly="True"
                />

                            <asp:BoundField
                DataField="name"
                HeaderText="name"
                SortExpression="name"
                />

                            <asp:BoundField
                DataField="description"
                HeaderText="description"
                />

                            <asp:BoundField
                DataField="price"
                HeaderText="price"
                ReadOnly="True"
                    
                            SortExpression="price"
                />

                        </Columns>

                    </asp:GridView>

                    <manu:PagerDataSource
                ID="PagerDataSource2"
                runat="server"
            
                        DataSourceID="PagerDataSource1"
                PageSize="14"
                    
                        OnPageChanged="PagerDataSource_PageChanged">

                    </manu:PagerDataSource>

                    <asp:ObjectDataSource
                ID="ObjectDataSource1"
                runat="server"
                TypeName="ProductsDAL2"
            
                        SelectMethod="GetPagedData"
                SelectCountMethod="CountAll"
                EnablePaging="True"

                        MaximumRowsParameterName="maxRows" StartRowIndexParameterName="startIndex"
            
                        UpdateMethod="Update"
                DeleteMethod="Delete" 
                        
                                OldValuesParameterFormatString="Original_{0}">

                    </asp:ObjectDataSource>

                </asp:Content>

The code-behind file (ASPX.CS) is:

 
                using System;

                using System.Web.UI.WebControls;

                using Manu.Web.UI.WebControls;

                public partial
                class CRUD_operations
                : System.Web.UI.Page

                {

                    protected void
                Page_Load(object sender, 
                    EventArgs e)

                    {

                    }

                    protected void
                PagerDataSource_PageChanged(object sender, PageChangedEventArgs e)

                    {

                        // if we have changed the curent
                    page and we were in edit mode, cancel editing

                        if (GridView1.EditIndex
                != -1) {

                            GridView1.EditIndex = -1;

                        }

                    }

                    protected void
                ObjectDataSource1_Deleted(object src,ObjectDataSourceStatusEventArgs
                e)

                    {

                        // the ObjectDataSource does
                    not automatically assign the afffected rows

                        e.AffectedRows = (int)e.ReturnValue;

                    }

                }