Select Data With LINQ-to-SQL Via WCF Service

This article demonstrates an interesting and very useful concept in LINQ-to-SQL.

Introduction

This article demonstrates an interesting and very useful concept in LINQ-to-SQL.

Question: What is select data with LINQ-to-SQL via WCF service?

In simple terms "It provides flexibility in the selection of data from a DB using LINQ-to-SQL context via WCF Service".

Step 1: Create a new web application

LINQ-to-SQL1.png

Step 2: Create a new WCF service application

wcf2.png

Step 3: Adding a new LINQ-to-SQL

wcf3.png

LINQ-to-SQL2.png

LINQ-to-SQL3.png

Step 4: The complete code of IService1.cs is as in the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
namespace WCFServiceApp
{
   
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1"
    //in both code and config file together.
    [ServiceContract]
   
public interface IService1
    {
        [
OperationContract]List<Employee> GetAllEmployees();
    }
}

Step 5: The complete code of Service1.svc.cs is as in the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;
namespace WCFServiceApp
{
   
// NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1"
    //in code, svc and config file together.
    public class Service1 : IService1
    {
       
public List<Employee> GetAllEmployees()
        {
            
var query = (from r in objContext.Employees select r);
           
return query.ToList();
        }
        #region Instance MembersDataClasses1DataContext objContext = new DataClasses1DataContext();
        #endregion
    }
}

Step 6: Adding a service reference

wcf5.png

Step 7: The complete code of WebForm1.aspx is as in the following:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="SelectData_WCF_LINQtoSQL.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">
    <style type="text/css">
        .grid {
           
margin-top: 50px;
        }
   
</style>
    <title></title>
</
head>
<
body>
    <form id="form1" runat="server">
        <center>
            <div>
                <table>
                    <tr>
                        <td colspan="2" align="center">
                            <asp:Label ID="Label1" runat="server" Text="Select Data with LINQ-to-SQL using WCF" 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" AutoGenerateColumns="False">
                                <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" />
                                <Columns>
                                    <asp:BoundField DataField="EmpId" HeaderText="Id" />
                                    <asp:BoundField DataField="FirstName" HeaderText="FirstName" />
                                    <asp:BoundField DataField="LastName" HeaderText="LastName" />
                                    <asp:BoundField DataField="Age" HeaderText="Age" />
                                </Columns>
                            </asp:GridView>
                        </td>
                    </tr>
                </table>
            </div>
        </center>
    </form>
</
body>
</
html>

Step 8: 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 SelectData_WCF_LINQtoSQL.ServiceReference1;
namespace SelectData_WCF_LINQtoSQL
{
   
public partial class WebForm1 : System.Web.UI.Page
    {
       
protected void Page_Load(object sender, EventArgs e){}
       
protected void Button1_Click(object sender, EventArgs e)
        {
            GridView1.DataSource = objClient.GetAllEmployees();
            GridView1.DataBind();
        }
        #region Instance MembersService1Client objClient = new Service1Client();
        #endregion
    }
}

Step 9: The output of the application is as in the following:

Output7.png

Step 10: The selected data output of the application is as in the following:

Output8.png

I hope this article was useful for you.