JavaFx combobox from mysql - mysql

Question

Good Day I am completely new to coding. I am building an app which uses a combobox besides other library items. The problem I am facing is that while attempting to populate combobox items from a Mysql Db the item values get duplicated each time the drop down is clicked.
How I can keep this from happening ? I do understand that my approach itself could be erroneous.
#FXML
public void getStation() {
String sqlStationName = " select * from station ";
try {
conn = (Connection) DBConnection.connect();
PreparedStatement pstStn = conn.prepareStatement(sqlStationName);
ResultSet stnRS = pstStn.executeQuery(sqlStationName);
while (stnRS.next()) {
comboBoxStation.getItems().add(stnRS.getString("stationName"));
}
stnRS.close();
pstStn.close();
conn.close();
} catch (SQLException ex) {
System.err.println("ERR" + ex);
}
}

Answer 1

Ok so I moved the function to the initialize() method in the controller and created an Observabale list called station
private ObservableList<String> stationsList = FXCollections.observableArrayList();
#Override
public void initialize(URL url, ResourceBundle rb) {
//
String sqlStationName = " select * from station ";
try {
conn = (Connection) DBConnection.connect();
PreparedStatement pstStn = conn.prepareStatement(sqlStationName);
ResultSet stnRS = pstStn.executeQuery(sqlStationName);
while (stnRS.next()) {
stationsList.add(stnRS.getString("stationName"));
}
stnRS.close();
pstStn.close();
conn.close();
} catch (SQLException ex) {
System.err.println("ERR" + ex);
}
}
and then left only this line in the original function....seems to be working.
#FXML
private void getStation() {
comboBoxStation.setItems(stationsList);
}