class Program
    {
        static void Main(string[] args)
        {
            // Create a connection string builder
            SqlConnectionStringBuilder csb = new SqlConnectionStringBuilder();
 
            // Define connection string attributes using three techniques
            csb.DataSource = "(local)";
            csb.Add("Initial Catalog", "master");
            csb["Integrated Security"] = true;
 
            // Output the connection string from the connection string builder
            Console.WriteLine("Connection string:\n{0}", csb.ConnectionString);
 
            // Create a connection string from the connection string builder
            SqlConnection connection = new SqlConnection(csb.ConnectionString);
            // Open and close the connection
            connection.Open();
            Console.WriteLine("\nConnectionState = {0}", connection.State);
            connection.Close();
            Console.WriteLine("ConnectionState = {0}", connection.State);
 
            Console.WriteLine("\nPress any key to continue.");
            Console.ReadKey();
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
      const string connStr = "Data Source=apex2006sql;Initial Catalog=Leather;Integrated Security=True;";
      const string query = "Select * From Invoice Where InvNumber = @InvNumber";
      using (DataTable dt = new DataTable())
      {
        using (SqlConnection conn = new SqlConnection(connStr))
        {
          conn.Open();
          using (SqlCommand cmd = new SqlCommand(query, conn))
          {
            cmd.Parameters.Add(new SqlParameter("@InvNumber", 1100));
            using (SqlDataReader dr = cmd.ExecuteReader())
            {
              dt.Load(dr);
            }
          }
          conn.Close();
        }
        System.Diagnostics.Debugger.Break();
      }
    }

"setup.exe" /qb ADDLOCAL=SQL_Engine,SQL_Data_Files,SQL_Replication,Client_Components,Connectivity,SQL_SSMSEE INSTANCENAME=SqlExpress SAVESYSDB=1 SQLBROWSERAUTOSTART=1 SQLAUTOSTART=1 AGTAUTOSTART=1 SECURITYMODE=SQL SAPWD=p@ssw0rd DISABLENETWORKPROTOCOLS=0 ERRORREPORTING=0 SQMREPORTING=0 ADDUSERASADMIN=1 INSTALLSQLDIR="%ProgramFiles%\Microsoft SQL Server\"