• Introduction
• Implementation

This architecture mainly consists of three layers –

1. Presentation Layer

This layer will mainly consist of user interface of the website.

2. Business Logic Layer

This layer acts as a mediator between Presentation layer and Data Access layer. This layer will have the business logic implementations and it transfers the data between the two layers.

3. Data Access Layer

This layer deals with the database and database related coding. We write stored procedures, queries in this layer.

4. Common layer

This is an optional layer.

Well, Lets get started!!!
1. Open MS Visual Studio 2008.
2. Create a project (file--new--project) with the name and choose option as “class library” as shown in picture. Give the file name as “tier.DAL”.





3. Repeat the second step for creating projects such as “tier.Common” and “tier.BLC”. DAL is used as Data access layer, BLC as Business layer, and common to hold common constants.
4.Save & close all the projects.
5. Open new MS VS 2008.
6. Now create new website by selecting file->new->Website and store it as given below.First create a new folder as tier.Website in the main projects folder, where you have all other projects.
7. Once that is done, add all projects under the solution(.sln) as shown below.








8. Once that is done, we got to save the main .sln file in folder “Project” where all the projects are stored.








9. Adding references : click on tier.BLC and add reference to tier.DAL. Similarly, for tier.web add reference to tier.BLC as follows –



Once references are set, its time to edit the cs files.
NOTE: In general practice, .common project is used to store the common parameters, for ex. to pass between stored procedures and the DAL project. But for demonstration purpose , I have skipped Stored Procedures part.
10. Under tier.DAL, the file tierDAL.cs should contain –

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.Data.SqlClient;
using System.Data;
using System.Collections;

namespace tier.DAL
{
    public class tierDAL
    {
        static SqlConnection conn;

        static bool connected;

        private static void Connect()

        {

            int count = 0;

            try

            {

                conn = new SqlConnection("User ID="Ur_userid"; Initial Catalog="ur_Initial_catalog"; 
                Integrated Security=SSPI; Persist Security Info=False; Data Source=localhost");
 

                try
                {
                    if (!connected)

                    {
                        conn.Open();
                    }

                }

                catch (Exception ex)

                {

                }

            }

            catch (SqlException ex)

            {

            }

            return;

        }

        private static void closeconnection()

        {
            if (connected)
            conn.Close();
        }

 

        public static ICollection GetData()

        {

            DataSet ds = new DataSet();

            if (!connected)

                Connect();

 

            SqlDataAdapter da = new SqlDataAdapter("", conn);

            string query = "SELECT Title,FirstName,LastName from Employees";

            da.SelectCommand = new SqlCommand(query, conn);

            da.Fill(ds, "Categories");

            return ds.Tables["Categories"].Rows;

        }

    }
}

    

12. In the Default.apx page, add a gridview control. Refer the below aspx code,





13. In the code behind, we need to call the Business logic layer’s GetData() method to bind the GridView. Refer the below code,

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

using System.Collections;
using tier.BLC;
using tier.DAL;

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {

            ICollection colcat = tierBLC.GetData();

            if (colcat.Count > 0)
            {

                GridView1.DataSource = ((DataRowCollection)colcat)[0].Table;

                GridView1.DataBind();

            }
        }

    }
}

    

That’s it. Build the solution now, run your project and see the output in browser. You will get output somewhat similiar to this –