JavaFx combobox from mysql
<p>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. </p>

<p>How I can keep this from happening ? I do understand that my approach itself could be erroneous.</p>

<pre><code>    @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);
    }

}
</code></pre>