Three Tier Architecture In ASP.NET

Let's start creating a 3-Tier Architecture Application.

Create a new project using "File", "New" , then "Project...".
In Visual C# select "Web".

(Select "ASP.NET Web application" and name it as: ThreeTierApp).
How to add class library to solution:

After clicking on a new project you would see the following screen. Select "Class Library" from this and name it "BusinessObject".

• Same(step: 3) as BusinessLogic, DataAccess.

• ThreeTierApp(in Solution Explorer)- Reference, Add Reference, Solutions, then Projects click (BusinessObject,BusinessLogic, DataAccess) Click
OK.
BusinessObject, then EmployeeBO and add Class,
BusinessObject, DBConnection add Class (For database Connection).

Web.config:

• Now we are done. Add all layers to our project.
• You can see the three tiers in the image given below.

Basically a 3-Tier architecture contains the following 3 layers:

1. Application Layer or Presentation Layer (our web form and UI Part)
2. Business Logic Layer (BusinessLogic)
3. Data Access Layer (DataAccess)
ThreeTierApp - add new webform,

Form Design

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<style type="text/css">
.auto-style1 {
text-align: center;
font-size: x-large;
}
.auto-style2 {
width: 488px;
}
.auto-style3 {
width: 95px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style="width:100%;">
<tr>
<td class="auto-style1" colspan="4"><strong>Employee Information</strong></td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3"> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3">Name :</td>
<td>
<asp:TextBox ID="txtName" runat="server" Width="200px"></asp:TextBox>
</td>
<td> </td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3">Address :</td>
<td>
<asp:TextBox ID="txtAddress" runat="server" Width="200px"></asp:TextBox>
</td>
<td> </td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3">Contact No :</td>
<td>
<asp:TextBox ID="txtContactNo" runat="server" Width="200px"></asp:TextBox>
</td>
<td> </td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3"> </td>
<td>
<asp:Button ID="btnSave" runat="server" OnClick="btnSave_Click" Text="Save" Width="58px" />
<asp:Label ID="lblMsg" runat="server"></asp:Label>
</td>
<td> </td>
</tr>
<tr>
<td class="auto-style2"> </td>
<td class="auto-style3"> </td>
<td> </td>
<td> </td>
</tr>
</table>
</div>
</form>
</body>
</html>

Now let’s start to create a table for saving this data using our 3-Tier Architecture.

CREATE TABLE[dbo].[Emp_Info]
(
[Id][int] IDENTITY(1, 1) NOT NULL, [Name][varchar](50) NULL, [Address][varchar](200) NULL, [ContactNo][int] NULL
) ON[PRIMARY]

Let's start with a business object first as in the following: Create a new class name, "EmployeeBO".

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BusinessObject
{
public class EmployeeBO
{
public string Name
{
get;
set;
}
public string Address
{
get;
set;
}
public int ContactNo
{
get;
set;
}
}
}

Now in the same way we created EmployeeBL in BusinessLogic, create a new class EmployeeDA in DataAccess.

The main thing TO DO

The main thing to do is to add the three layers:

EmployeeBO.cs
BusinessLogic.cs
EmployeeDA .cs

Last Step:

Save Button btnSave_Click

using BusinessLogic; // Creating object of Business Layer
using BusinessObject; // Creating object of Business Object
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace ThreeTierApp
{
public partial class EmployeeInfo: System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e) {}
EmployeeBO oEmployeeBO = new EmployeeBO(); // Creating object of Business Object
EmployeeBL oEmployeeBL = new EmployeeBL(); // Creating object of Business Logic
protected void btnSave_Click(object sender, EventArgs e)
{
oEmployeeBO.Name = txtName.Text;
oEmployeeBO.Address = txtAddress.Text;
oEmployeeBO.ContactNo = Convert.ToInt32(txtContactNo.Text);
string msg = oEmployeeBL.Save(oEmployeeBO);
lblMsg.ForeColor = Color.Green;
lblMsg.Text = msg.ToString();
}
}
}

EmployeeBL.cs

using BusinessObject;
using DataAccess;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BusinessLogic
{
public class EmployeeBL
{
EmployeeDA oEmployeeDA = new EmployeeDA(); // Creating object of Data Access
public string Save(EmployeeBO oEmployeeBO)
{
return oEmployeeDA.Save(oEmployeeBO);
}
}
}

EmployeeDA.cs

using BusinessObject;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DataAccess
{
public class EmployeeDA: DBConnection // Inherited DBConnection Class
{
public string Save(EmployeeBO oEmployeeBO)
{
try
{
connection.Open();
string query = "insert into Emp_Info (Name,Address,ContactNo)values(@Name,@Address,@ContactNo)";
command.CommandText = query;
command.Parameters.Clear();
command.Parameters.AddWithValue("@Name", oEmployeeBO.Name);
command.Parameters.AddWithValue("@Address", oEmployeeBO.Address);
command.Parameters.AddWithValue("@ContactNo", oEmployeeBO.ContactNo);
command.ExecuteNonQuery();
connection.Close();
return "Save Success.";
} finally
{
connection.Close();
}
}
}
}

9 Comments

Join the conversation! Your thoughts help the community grow.

Ramzanali Momin8y ago
Nice article
Sanabeal Kabir10y ago
Thanks
Santhakumar Munuswamy10y ago
Welcome
Santhakumar Munuswamy10y ago
Good Start
Muhammad Aqib Shehzad10y ago
Good Share:
Jasminder Singh10y ago
@Sanabeal, This is more of 3 layer architecture. Tier is different from layer. So this should have been 3 layer architecture. Correct me if I am wrong.
- Ranjan Dailata10y ago
  The layers are a logical separation whereas the tiers are a physical separation. That's the primary difference between Tire vs Layer
Sridhar Sharma10y ago
Nice share
Nanddeep Nachan10y ago
Nice article. Can you please elaborate - how easy or difficult is it to change the underlying database without change in code in this case?