将整数值添加到数据库表中错误

Question

我正在Java创建一个航班应用程序，它应该做的事情之一是添加一个新的航班到数据库。我可以添加航班名称没有问题，但我有问题添加航班的座位数到数据库。数据库表被设置为将座席数作为整数值。在我的代码中，将这个值从用户界面添加到数据库的函数将一个值作为整数参数。然后，在添加新航班的实际按钮的事件处理程序代码中，我将值从字符串（这是文本框中接受的字符串）转换为整数，以便将值输入数据库。然而，当我运行我的代码时，我得到一个错误，说座席数不能被接受为空值。基本上，数据库将该值作为空值。我不确定我在代码中做错了什么。

public class Flight extends Customer {
        private static ArrayList<String> FlightNames;
        private static ArrayList<Integer> Seats;
        private static PreparedStatement getFlightnames;
        private static PreparedStatement getFlightSeats;
        private static PreparedStatement addFlightName;
        private static PreparedStatement addSeats;
        private static ResultSet fresult;
        private static ResultSet sresult;

        public static ArrayList <String> getFlightnames(){
            //recieve flight names from database
            try{
                FlightNames = new ArrayList();
                getFlightnames = getConnection().prepareStatement("select name from flight ");
                fresult = getFlightnames.executeQuery();
                while(fresult.next()){
                    FlightNames.add(fresult.getString(1));

                }

            }
            catch(SQLException result){
                result.printStackTrace();
            }
            return FlightNames;

        }
        public ArrayList<Integer> getFlightSeats(){
            try{
            Seats = new ArrayList();
            //getFlightSeats = getConnection().prepareStatement("SELECT * FROM Flight WHERE Seats LIKE ?");
            getFlightSeats = getConnection().prepareStatement("select seats from flight ");
            sresult = getFlightSeats.executeQuery();
                while(sresult.next()){
                    Seats.add(sresult.getInt(1));

                }
            }

            catch(SQLException result){
                result.printStackTrace();
            }
            return Seats;
        }
        public void addFlight(String flight){
            try{
                addFlightName = getConnection().prepareStatement("insert into bookings (flight) values(?)");
                addFlightName.setString(1, flight);
                addFlightName.executeUpdate();

            }
            catch(SQLException result){
                result.printStackTrace();
            }
        }
        public void addNumber(String flightNumber){
            try{
                addFlightName = getConnection().prepareStatement("insert into flight (name) values(?)");
                addFlightName.setString(1, flightNumber);
                addFlightName.executeUpdate();

            }
            catch(SQLException result){
                result.printStackTrace();
            }
        }
        public void addSeats(int seats){
            try{
                addSeats = getConnection().prepareStatement("insert into flight (seats) values(?)");
                addSeats.setInt(1, seats);
                addSeats.executeUpdate();

            }
            catch(SQLException result){
                result.printStackTrace();
            }
        }

}

private void AddFlightButtonActionPerformed(java.awt.event.ActionEvent evt) {                                                
        Flight addnumber = new Flight();
        Flight addseats = new Flight();
        addnumber.getConnection();
        addseats.getConnection();
        String flight = FlightTextBox.getText();
        String seats = SeatsTextBox.getText();
        int seatsInt = Integer.parseInt(seats);
        addnumber.addNumber(flight);
        addseats.addSeats(seatsInt);

        AddFlightStatusLabel.setText("The flight " + flight + " has been added with " + seats + " seats" );
        BookFlightComboBox.setModel(new javax.swing.DefaultComboBoxModel(Flight.getFlightnames().toArray()));
        StatusFlightComboBox.setModel(new javax.swing.DefaultComboBoxModel(Flight.getFlightnames().toArray()));
        WaitFlightComboBox.setModel(new javax.swing.DefaultComboBoxModel(Flight.getFlightnames().toArray()));
    }

Answer 1

看起来您使用了错误的表添加座位或错误的表索引。

编辑：检查表列后，您需要为两个函数添加类似这样的查询，但建议只使用类似这样的单个方法：

public void addFlightDetail(String flightNumber, int seats){

  addFlightName = getConnection().prepareStatement("insert into flight (name, seats)
  values(?,?)");
  addFlightName.setString(1, flightNumber);
  addFlightName.setInt(1, seats);
}