При запуске программы C# COMBOBOX не показывает данные из БД типа SelectedIndex

   public WindowAlbumEditAdd(string id)
        {
            InitializeComponent();
            LoadCmbGroup();
            LoadCmbCountrys();
            LoadCmbDistruts();
            LoadCmbStudios();
            f = 1;
            _id = id;
            using (SqlConnection sqlConnection = new SqlConnection(ConnectionString))
            {
                sqlConnection.Open();
                SqlCommand select = new SqlCommand($"SELECT Album.name_Album, Album.date_zap, " +
                    "Album.date_sale, Group_.name_Group, Country.ter_raspr, Studio.name_studio, Distrub.name_Distrud " +
                    "FROM Album " +
                    "INNER JOIN Group_ ON Album.group_id = Group_.id_Group " +
                    "INNER JOIN Country ON Album.country_id = Country.id_Country " +
                    "INNER JOIN Studio ON Album.studio_id = Studio.id_Studio " +
                    $"INNER JOIN Distrub ON Album.distrub_id = Distrub.id_Distrub WHERE id_album = '{_id}'", sqlConnection);
                SqlDataReader reader = select.ExecuteReader();
                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        tbName.Text = reader.GetString(0);
                        dtZap.SelectedDate = reader.GetDateTime(1);
                        dtSale.SelectedDate = reader.GetDateTime(2);
                        cmbGroup.SelectedIndex = int.Parse(_id);
                        cmbCountry.SelectedIndex = int.Parse(_id);
                        cmbStudio.SelectedIndex = int.Parse(_id);
                        cmbDistrub.SelectedIndex = int.Parse(_id);
                    }
                }
            }
        }

Только почему то не работает cmbGroup.SelectedIndex = int.Parse(_id); не понимаю почему _id это ID записи