如何根据用户输入（扫描器）获取 SQL 准备好的语句

Question

我很难创建准备好的语句 SELECT 并打印出满足条件的行：

SELECT ReservationStartDate, ReservationEndDate FROM treservations WHERE ReservationStartDate< **?** AND ReservationEndDate> **?**

“？”用户输入 - 字符串，例如 2019-07-09 和 2019-08-16

我可以 SELECT* 使用以下方法：

public static List<Reservation> getAllReservation(){
        List<Reservation> reservationsList = new ArrayList<>();
        String sql = "SELECT * FROM `treservations`";
        try{
            PreparedStatement ps = ConnectorDB.connection.prepareStatement(sql);
            ResultSet resultSet = ps.executeQuery();
            while (resultSet.next()){
                Reservation reservation = new Reservation();
                reservation.setReservationID(resultSet.getInt("ReservationID"));
                reservation.setCarID(resultSet.getInt("CarID"));
                reservation.setReservationStartDate(resultSet.getString("ReservationStartDate"));
                reservation.setReservationEndDate(resultSet.getString("ReservationEndDate"));
                reservation.setPesel(resultSet.getString("Pesel"));
                reservationsList.add(reservation);
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        return reservationsList;
    }

例如，根据扫描仪的用户输入插入新行，例如：

public static List<Reservation> getAllReservation(){
        List<Reservation> reservationsList = new ArrayList<>();
        String sql = "SELECT * FROM `treservations`";
        try{
            PreparedStatement ps = ConnectorDB.connection.prepareStatement(sql);
            ResultSet resultSet = ps.executeQuery();
            while (resultSet.next()){
                Reservation reservation = new Reservation();
                reservation.setReservationID(resultSet.getInt("ReservationID"));
                reservation.setCarID(resultSet.getInt("CarID"));
                reservation.setReservationStartDate(resultSet.getString("ReservationStartDate"));
                reservation.setReservationEndDate(resultSet.getString("ReservationEndDate"));
                reservation.setPesel(resultSet.getString("Pesel"));
                reservationsList.add(reservation);
            }
        }catch (SQLException e){
            e.printStackTrace();
        }
        return reservationsList;
    }

问题是如何结合这两种方法并能够根据用户扫描仪输入 SELECT 数据库中的行（然后将它们打印出来）。

我的思路： 1. 我们根据用户输入创建预订对象

    public static Reservation clientReservationMenuInput(){
        Scanner scanner = new Scanner(System.in);
        String regData = "\d{4}-\d{2}-\d{2}";
        System.out.println("2 Reservation start date (YYYY-MM-DD) ");
        String ReservationStartDate;
        while (!(ReservationStartDate=scanner.next()).matches(regData)){
            System.out.printf("Date format not correct, Please try once again\n");
        }
        System.out.println("3 Reservation end date (YYYY-MM-DD) ");
        String ReservationEndDate;
        while (!(ReservationEndDate=scanner.next()).matches(regData)){
            System.out.printf("Date format not correct, Please try once again\n");
        }
        Reservation reservation = new Reservation();
        reservation.setReservationStartDate(ReservationStartDate);
        reservation.setReservationEndDate(ReservationEndDate);
        return reservation;
    }

创建的对象是checkDatesForReservation方法的参数
SQL 其中两个参数“？”表示用户输入的日期
我需要 while 循环来查找所有行
最后我需要 return 一个列表

    public static List<Reservation> checkDatesForReservation(Reservation reservation){
        List<Reservation> reservationList = new ArrayList<>();
        String sql2= "SELECT ReservationStartDate, ReservationEndDate FROM treservations WHERE ReservationStartDate=? AND ReservationEndDate= ?";
        try{
            PreparedStatement ps = ConnectorDB.connection.prepareStatement(sql2);
            ResultSet resultSet = ps.executeQuery();
            while (resultSet.next()){
                ps.setString(1,reservation.getReservationStartDate());
                ps.setString(2,reservation.getReservationEndDate());
                reservationList.add(reservation);
            }
        }catch (SQLException e){
            e.getStackTrace();
        }
        return reservationList;
    }

Answer 1

执行语句前需要设置参数

        PreparedStatement ps = ConnectorDB.connection.prepareStatement(sql2);
        ps.setString(1,reservation.getReservationStartDate());
        ps.setString(2,reservation.getReservationEndDate());
        ResultSet resultSet = ps.executeQuery();
        while (resultSet.next()){
            reservationList.add(reservation);
        }

Answer 2

请参考JDBC PreparedStatement example – Select list of the records

 public static List<Reservation> checkDatesForReservation(Reservation reservation){
        Reservation reservation = null;
        List<Reservation> reservationList = new ArrayList<>();
        String sql2= "SELECT ReservationStartDate, ReservationEndDate FROM treservations WHERE ReservationStartDate=? AND ReservationEndDate= ?";
        try{
            PreparedStatement ps = ConnectorDB.connection.prepareStatement(sql2);
            ps.setString(1,reservation.getReservationStartDate());
            ps.setString(2,reservation.getReservationEndDate());
            ResultSet resultSet = ps.executeQuery();
            while (resultSet.next()){
               reservation = new Reservation();
               reservation.setReservationStartDate(rs.getString("ReservationStartDate"));
               reservation.setReservationEndDate(rs.getString("ReservationEndDate"));
               reservationList.add(reservation);
            }
        }catch (SQLException e){
            e.getStackTrace();
        }
        return reservationList;
    }

如何根据用户输入（扫描器）获取 SQL 准备好的语句

How to get SQL prepared statement based on user input (scanner)

java

sql

jdbc

prepared-statement

java.util.scanner