ADO-db-test

namespace ADODatabases {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e) {
            string connStr = @"Data Source=hansen-laptop\SQLEXPRESS;
          database=Northwind;Integrated Security=True";

            SqlConnection con = new SqlConnection(connStr);
            string sql = "SELECT distinct country FROM customers";

            SqlCommand cmd = new SqlCommand(sql, con);
            con.Open();

            SqlDataReader reader = cmd.ExecuteReader();
            while (reader.Read()) {
                string line ="" + reader[0];
                comboBox1.Items.Add(line);
            }
            con.Close();

        }

        private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e) {
            string connStr = @"Data Source=hansen-laptop\SQLEXPRESS;
          database=Northwind;Integrated Security=True";

            SqlConnection con = new SqlConnection(connStr);
            string sql = "SELECT ContactName, City FROM customers WHERE country=@country";

            SqlCommand cmd = new SqlCommand(sql, con);

            cmd.Parameters.AddWithValue("@country", comboBox1.SelectedValue.ToString());

            con.Open();

            SqlDataReader reader = cmd.ExecuteReader();
            listBox1.Items.Clear();
            while (reader.Read()) {
                string line = "" + reader[0];
                listBox1.Items.Add(line);
            }
            con.Close();
        }
    }
}