N-Layer Application in ASP.NET WebForm

I'm mentoring a student and he's very much in-love in programming. He showed me his first simple N-Tier application in TDD approach.

It's a very simple application, but I'm sure newbies could learn something from this.

Test Layer:

        [Test]
        public void DAL_Should_Return_A_List_Of_Kampung()
        {
            List<Kampung> kampung = KampungData.ListOfKampung();
            Assert.IsNotNull(kampung);
        }

Data Layer:

public static List<Kampung> ListOfKampung()
        {
            try
            {
                var results = new List<Kampung>();
                const string connectionString = "Data Source=HACK3R;Initial Catalog=KampungDB;Integrated Security=True";
                using (var con = new SqlConnection(connectionString))
                {
                    using (var cmd = new SqlCommand("ListOfKampung", con))
                    {
                        cmd.CommandType = CommandType.StoredProcedure;
                        try
                        {
                            con.Open();
                            using (var reader = cmd.ExecuteReader())
                            {
                                while (reader.Read())
                                {
                                    results.Add(
                                        new Kampung
                                            {
                                    KampungId = reader.GetInt32(0),
                                    Name = reader.GetString(1),
                                    Age = reader.GetInt32(2),
                                    Salary = reader.GetDecimal(3),
                                    Score = reader.GetDecimal(4),
                                    DateAdded = reader.GetDateTime(5),
                                    DateUpdated = reader.GetDateTime(6)
                                }
                                        );
                                }
                                reader.Close();
                            }
                        }
                           
                        catch (Exception ex)
                        {
                            Console.WriteLine("Data Error: {0}", ex.Message);
                        }
                        return results;
                    }
                   
                }
                }
            catch (Exception)
            {
                throw new ApplicationException("Unable to get data from the database.");
            }
        }

Business Layer:

using System;

namespace KampungProject.Applications
{
    public class Kampung
    {
        public Kampung()
        { }

        public Kampung(int kampungId, string name, int age, decimal salary, decimal score, DateTime dateAdded, DateTime dateUpdated)
        {
            KampungId = kampungId;
            Name = name;
            Age = age;
            Salary = salary;
            Score = score;
            DateAdded = dateAdded;
            DateUpdated = dateUpdated;
        }

        public int KampungId { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
        public decimal Salary { get; set; }
        public decimal Score { get; set; }
        public DateTime DateAdded { get; set; }
        public DateTime DateUpdated { get; set; }
    }
}

Presentation Layer:

using System;
using System.Collections.Generic;
using KampungProject.Applications;

namespace KampungProject
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected List<Kampung> Kampungs;

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                ViewKampungList();
            }
        }

        private void ViewKampungList()
        {
            Kampungs = KampungData.ListOfKampung();
            GridView1.DataSource = Kampungs;
            GridView1.DataBind();
        }
    }
}