小编Bat*_*atz的帖子

我正在尝试获取客户端到达日期并将其与我的SQL数据库进行比较,以查看在我的数据库中是否存在相同的日期.但是我收到以下错误:The operator > is undefined for the argument type(s) java.lang.String, java.lang.String

PS我需要通过java比较它而不是使用sql查询

public void makeNewReservation() throws ParseException {
    // Enter informations

    System.out.println("Date of arrivel?");
    Scanner in = new Scanner(System.in);
    String date_entree = in.next();
    System.out.println("Date of exit? dd/MM/yyyy");
    String date_sortiee = in.next();
    calculateDaysDifference(date_sortiee, date_entree);



public  void calculateDaysDifference(String date_entree, String date_sortiee) throws ParseException{


ConnectionMySQL myConnection=new ConnectionMySQL();
    Connection conSQL=myConnection.startDBConnection();
    boolean connectionOK=myConnection.checkConnection(conSQL);

    String query = ("SELECT `START_DATE`,`END_DATE` FROM `room_booking");


    //if everything is fine with the connection, i try to execute a query
    if …