Select Data Using Entity Objects

Vijay Prativadi
11y
4.9k
0
0

Article

Introduction

This article demonstrates an interesting and very useful concept in Entity Framework.

Question: What are entity command objects?

In simple terms "It enables use of entity command objects to query based on the Entity Framework".

Step 1: Create a new web application

Step 2: Adding a new Entity Data Model Framework

Step 3: The complete code of WebForm1.aspx is as in the following:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="EntityClientSelectData.WebForm1" %>
<!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 id="Head1" runat="server">
     <title></title>
</head>
<body>
     <form id="form1" runat="server">
         <div>
             <center>
                 <div>
                     <table>
                         <tr>
                             <td colspan="2" align="center">
                                 <asp:Label ID="Label1" runat="server" Text="Select Data - Entity Client" Font-Bold="true" Font-Size="Large" Font-Names="Verdana"
ForeColor="Maroon"></asp:Label></td>
                         </tr>
                         <tr>
                             <td colspan="2" align="center">
                                 <asp:Button ID="Button1" runat="server" Text="Select Data" Font-Names="Verdana" Width="213px" BackColor="Orange" Font-Bold="True"
OnClick="Button1_Click" /></td>
                         </tr>
                         <tr>
                             <td colspan="2" align="center">
                                 <asp:GridView ID="GridView1" runat="server" CssClass="grid" BackColor="LightGoldenrodYellow" BorderColor="Tan" BorderWidth="1px" CellPadding="2"
ForeColor="Black" GridLines="None">
                                     <AlternatingRowStyle BackColor="PaleGoldenrod" />
                                     <FooterStyle BackColor="Tan" />
                                     <HeaderStyle BackColor="Tan" Font-Bold="True" />
                                     <PagerStyle BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue" HorizontalAlign="Center" />
                                     <SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite" />
                                     <SortedAscendingCellStyle BackColor="#FAFAE7" />
                                     <SortedAscendingHeaderStyle BackColor="#DAC09E" />
                                     <SortedDescendingCellStyle BackColor="#E1DB9C" />
                                     <SortedDescendingHeaderStyle BackColor="#C2A47B" />
                                     <EmptyDataTemplate>No Records Found!</EmptyDataTemplate>
                                 </asp:GridView>
                             </td>
                         </tr>
                     </table>
                 </div>
             </center>
         </div>
     </form>
</body>
</html>

Step 4: The complete code of WebForm1.aspx.cs is as in the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.EntityClient;
using System.Data;
namespace EntityClientSelectData
{
     public partial class WebForm1 : System.Web.UI.Page
     {
         protected void Page_Load(object sender, EventArgs e) { }
         protected void Button1_Click(object sender, EventArgs e)
         {
             using (EntityConnection objConn = new EntityConnection("name=CompanyEntities"))
             {
                 objConn.Open(); using (EntityCommand command = new EntityCommand("SELECT VALUE e FROM
                     CompanyEntities.tblEmployee AS e", objConn))
                 {
                     EntityDataReader objReader = command.ExecuteReader(CommandBehavior.SequentialAccess);
                     GridView1.DataSource = objReader;
                     GridView1.DataBind();
                 }
             }
         }
     }
}

Step 5: The output of the application is as in the following:

Step 6: The select data output of the application is as in the following:

I hope this article was useful for you. I look forward for your comments and feedback. Thanks Vijay.

Up Next

Ebook Download

View all

OOPs Principle and Theory

Read by 5.1k people

Download Now!

Learn

View all

MVC Corporation

MVC Corporation is consulting and IT services based company.