How Do I Create Intergrated Database With C# Application?

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace EnQApp
{
    public partial class LoGEnq : Form
    {
        public LoGEnq()
        {
            InitializeComponent();
        }

        private void Btn1_Click(object sender, EventArgs e)
        {
            String Usrname = UName.Text;
            SqlConnection cn = new SqlConnection(global::DataBaseTest.Propeties.Settings.Default.Database1ConnectionString);

            try {
                cn.Open();
                SqlCommand cmd = new SqlCommand();
                cmd.CommandText = "SELECT * FROM Login WHERE Uname=@Usr;";
                cmd.Parameters.AddWithValue("@Usr",Usrname);

                cmd.ExecuteNonQuery();
                MessageBox.Show("Thank you");
            }
            catch (Exception ex) { }
            finally { }
        }