public void readSQL()
        {
            string sql = " SELECT * FROM teacher  ";
            MySqlConnection con = new MySqlConnection("host=localhost;user=root;password=859694;database=projekt;");
            MySqlCommand cmd = new MySqlCommand(sql, con);

            con.Open();

           MySqlDataReader  reader = cmd.ExecuteReader();

           while (reader.Read()) {
               data2txt.Text = reader.GetString("id");
              datatxt.Text = reader.GetString("userId");
           }

        }