我正在用java创建一个航类应用程序，它应该做的事情之一就是向数据库添加一个新的航类。我可以毫无问题地添加航类名称，但在将航类的座位数添加到数据库中时遇到问题。数据库表设置为将座位数作为整数值。在我的代码中，我的函数将该值从用户界面添加到数据库中，将一个值作为整数参数。然后，在添加新航类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，以便可以将该值输入到数据库。但是，当我运行代码时，出现错误，指出座位数不能接受为空值。基本上，数据库将值视为空。我不确定我的代码中做错了什么。
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()));
}
最佳答案
您似乎使用了错误的 table 来添加座位，或者为 table 添加了错误的索引。
编辑: 检查表列后，您需要为这两个函数添加这样的查询，但建议仅使用这样的单一方法:
public void addFlightDetail(String flightNumber, int seats){
addFlightName = getConnection().prepareStatement("insert into flight (name, seats)
values(?,?)");
addFlightName.setString(1, flightNumber);
addFlightName.setInt(1, seats);
}
关于java - 将整数值添加到数据库表错误，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57334810/