JavaFX GUI / MySQL从customers表中检索记录

Question

创建一个JavaFX GUI，允许用户从pcparts数据库中的customers表中检索记录.GUI应该允许用户指定所需的字段，所需的顺序和where条件。仅显示所需的字段您可以以任何方式在GUI中显示记录。

我在mac上修复了MySQL的初始问题。但是，现在我的实际程序运行不正常。界面出现但无法从sql表中检索任何信息。它要么无法读取我的where条件，要么检查表中的任何字段都包含未知字段。

这是我到目前为止为java程序所做的：

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import java.sql.*;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.scene.control.TextField;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;



public class JavaGUI extends Application {

// @Override

private String query = " ";
private PreparedStatement preparedStatement;
private TextArea ta = new TextArea ();
private TextField where = new TextField ();

public void start (Stage primaryStage)
{
BorderPane pane = new BorderPane();
VBox vbox = new VBox(10);
CheckBox chkCustID = new CheckBox("customer ID");
CheckBox chkName = new CheckBox("name");
CheckBox chkAddress = new CheckBox("address");
CheckBox chkCity = new CheckBox("city");
CheckBox chkState = new CheckBox("state");
CheckBox chkZip = new CheckBox("zip");
vbox.setPadding(new Insets(10,10,10,10));
vbox.getChildren().addAll (chkCustID, chkName , chkAddress , chkCity , chkState , chkZip );
HBox hbox = new HBox(10);
Button btSumbit = new Button("submit");
hbox.setAlignment(Pos.CENTER);
hbox.setPadding(new Insets(10,10,10,10));
hbox.getChildren().add(btSumbit);

HBox hbox2 = new HBox(10);
Label label = new Label("Type the where condition: ");
where.setPrefColumnCount(40);
hbox2.setPadding(new Insets(10,10,10,10));
hbox2.getChildren().addAll(label,where);
pane.setPadding(new Insets(10,10,10,10));
pane.setTop(hbox2);
pane.setLeft(vbox);
pane.setBottom(hbox);
pane.setRight(ta);
Scene scene = new Scene(pane);
primaryStage.setTitle("PcParts");
primaryStage.setScene(scene);
primaryStage.show( );
EventHandler<ActionEvent> handler = e -> {
if (chkCustID.isSelected ( ) )
query = query + "custid, ";
if (chkName.isSelected ( ) )
query = query + "name, ";
if (chkAddress.isSelected ( ) )
query = query + "address, ";
if (chkCity.isSelected ( ) )
query = query + "city, ";
if (chkState.isSelected ( ) )
query = query + "state, ";
if (chkZip.isSelected ( ) )
query = query + "zip, ";
};
chkCustID.setOnAction(handler);
chkName.setOnAction(handler);
chkAddress.setOnAction(handler);
chkCity.setOnAction(handler);
chkState.setOnAction(handler);
chkZip.setOnAction(handler);
btSumbit.setOnAction ( e -> {
initializeDB ( ) ;
display();
} ) ;
}


private void initializeDB ( )
{
try
{
Class.forName("com.mysql.jdbc.Driver");
System.out.println("Driver Laoded");
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost/pcparts");
System.out.println("Database Connected");
String queryString = "select" + query + "where" + where.getText ();
preparedStatement = connection.prepareStatement (queryString);
}
catch (Exception ex)
{
ex.printStackTrace ();
}
}
private void display()
{
try
{
ResultSet rset = preparedStatement.executeQuery ( );
if (rset.next())
{
String custid = rset.getString("custid");
String name = rset.getString("name");
String address = rset.getString("address");
String city = rset.getString("city");
String state = rset.getString("state");
String zip = rset.getString("zip");

String finalstring = filter(custid) + filter(name) + filter(address) + filter(city) + filter(state) + filter(zip);

ta.setText(finalstring);
}
}
catch (SQLException e )
{
e.printStackTrace ( );
}
}


public static String filter ( String str)
{
String x = " ";
if(str != null)
{
return str;
}
else
return x;
}


public static void main(String[] args) {
launch(args);
}

}

这是pcparts.sql：

    -- phpMyAdmin SQL Dump
-- version 3.1.3.1
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jul 01, 2009 at 03:19 PM
-- Server version: 5.1.33
-- PHP Version: 5.2.9-2

SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

--
-- Database: `pcparts`
--
CREATE DATABASE `pcparts` DEFAULT CHARACTER SET latin1 COLLATE latin1_swedish_ci;
USE `pcparts`;

-- --------------------------------------------------------

--
-- Table structure for table `customers`
--

CREATE TABLE IF NOT EXISTS `customers` (
  `custid` int(10) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL,
  `address` char(20) NOT NULL,
  `city` char(16) NOT NULL,
  `state` char(2) NOT NULL,
  `zip` char(5) NOT NULL,
  PRIMARY KEY (`custid`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;

--
-- Dumping data for table `customers`
--

INSERT INTO `customers` (`custid`, `name`, `address`, `city`, `state`, `zip`) VALUES
(1, 'Smith, Tim', '12 Elm St', 'Tampa', 'FL', '34567'),
(2, 'Jones, Tom', '435 Oak Dr', 'Dunedin', 'FL', '33245'),
(3, 'Avery, Bill', '623 Ash Ave', 'Clearwater', 'FL', '33655'),
(4, 'Kerr, Debra', '1573 Yew Crt', 'Clearwater', 'FL', '33442');

-- --------------------------------------------------------

--
-- Table structure for table `orders`
--

CREATE TABLE IF NOT EXISTS `orders` (
  `orderid` int(10) NOT NULL AUTO_INCREMENT,
  `custid` int(10) NOT NULL,
  `sku` char(5) NOT NULL,
  `quantity` int(10) NOT NULL,
  `date` date NOT NULL,
  PRIMARY KEY (`orderid`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ;

--
-- Dumping data for table `orders`
--

INSERT INTO `orders` (`orderid`, `custid`, `sku`, `quantity`, `date`) VALUES
(1, 2, 'C7615', 2, '2005-08-24'),
(2, 2, 'K9907', 1, '2005-08-24'),
(3, 3, 'C7615', 1, '2005-08-25'),
(4, 3, 'F0993', 1, '2005-08-25'),
(5, 1, 'B2245', 1, '2005-08-26');

-- --------------------------------------------------------

--
-- Table structure for table `parts`
--

CREATE TABLE IF NOT EXISTS `parts` (
  `sku` char(5) NOT NULL,
  `descrip` char(16) NOT NULL,
  `manuf` char(16) NOT NULL,
  `price` float(5,2) DEFAULT NULL,
  PRIMARY KEY (`sku`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

--
-- Dumping data for table `parts`
--

INSERT INTO `parts` (`sku`, `descrip`, `manuf`, `price`) VALUES
('B2245', 'DVD Drive', 'Sony', 79.99),
('C7615', '1 GB Flash Dr', 'Sandisk', 49.95),
('F0993', 'Laptop Mouse', 'Logitech', 29.99),
('H2243', 'G router', 'Linksys', 59.99),
('U8872', 'G PC Card', 'Linksys', 54.95),
('K9907', '4 port USB Hub', 'Acer', 12.95);

这是错误：

Driver Loaded
Database Connected
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'where customers' at line 1
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
    at com.mysql.jdbc.Util.getInstance(Util.java:387)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:941)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2550)
    at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1861)
    at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1962)
    at derienzo32.JavaGUI.display(JavaGUI.java:114)
    at derienzo32.JavaGUI.lambda$1(JavaGUI.java:86)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8411)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$355(GlassViewEventHandler.java:388)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)