java – 使用已排序的主键和外键JDBC的列添加行
作者：互联网
我的程序有一个添加项目和完成交易选项. FinishTransaction类要求用户输入客户的信息,付款方式和付款.
总付款显示在窗口中.当用户单击结帐按钮时,数据应从CUSTOMER表(插入客户信息),ORDERS表(插入项目的信息)和TRANSACTION表(插入交易信息)中传输.
事务表有一列TRANS_CUSTNUM,它是一个引用CUSTOMER表中CUST_NUM的外键.
我的程序工作正常,除了TRANSACTION表.它不会在我的SQL开发人员中添加一行.您认为我的代码有什么问题？
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.sql.*;
import java.util.logging.*;
public class FinishTransaction extends JFrame implements ActionListener{
JLabel totalLabel;
JLabel nameLabel;
JLabel addressLabel;
JLabel contactLabel;
JLabel custPaymentLabel;
JLabel methodLabel;
JLabel creditCardLabel;
JTextField totalTextField;
JTextField nameTextField;
JTextField addressTextField;
JTextField contactTextField;
JTextField custPaymentTextField;
JTextField creditCardTextField;
final JButton mainMenuButton = new JButton("Main Menu");
final ButtonGroup bGroup = new ButtonGroup();
final JRadioButton cashRadioButton = new JRadioButton("Cash");
final JRadioButton creditRadioButton = new JRadioButton("Credit Card");
final JButton checkoutButton = new JButton("Checkout");
static FinishTransaction fin = new FinishTransaction();
static AddItem add = new AddItem();
static int total = 0;
static int payment = 0;
static int change = 0;
static String payment_desc;
static int creditCard;
public FinishTransaction(){
//ui
}
public void actionPerformed(ActionEvent e){
if(checkoutButton.getName().equals(((Component)e.getSource()).getName())){
try{
payment = Integer.parseInt(custPaymentTextField.getText());
if(payment>=total){
change = payment - total;
JOptionPane.showMessageDialog(this, "Thank you for shopping! Your change is "+change, "Exiting", JOptionPane.INFORMATION_MESSAGE);
}
else
JOptionPane.showMessageDialog(this, "Your payment is not enough. Please try again!", "Error!", JOptionPane.ERROR_MESSAGE);
}
catch(NumberFormatException a){
JOptionPane.showMessageDialog(this, "Invalid input", "Error!", JOptionPane.ERROR_MESSAGE);
}
Connection conn = null;
PreparedStatement pstmt = null;
PreparedStatement pstmt2 = null;
PreparedStatement pstmt3 = null;
String URL = "jdbc:oracle:thin:@VAIO:49160:xe";
String USER = "mariel";
String PASS = "1234";
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
try {
String name = nameTextField.getText();
String address = addressTextField.getText();
int contact = Integer.parseInt(contactTextField.getText());
conn = DriverManager.getConnection(URL, USER, PASS);
String sql = "INSERT INTO CUSTOMER " +
"VALUES(CustNumSeq.NEXTVAL, ?, ?, ?)";
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, name);
pstmt.setString(2, address);
pstmt.setInt(3, contact);
pstmt.executeUpdate();
for(int index=0;index<add.itemNum.length;index++){
String sql2 = "INSERT INTO ORDERS "+
"VALUES(OrderNumSeq.NEXTVAL, ?, ?)";
pstmt2 = conn.prepareStatement(sql2);
pstmt2.setInt(1,add.itemNum[index]);
pstmt2.setInt(2, add.quantity[index]);
pstmt2.executeUpdate();
}
creditCard = Integer.parseInt(creditCardTextField.getText());
String sql3 = "INSERT INTO TRANSACTION " +
"VALUES(TransNumSeq.NEXTVAL, CustNumSeq.NEXTVAL, ?, ?, ?, ?)";
pstmt3 = conn.prepareStatement(sql3);
pstmt3.setInt(1, payment);
pstmt3.setString(2, payment_desc);
pstmt3.setInt(3, creditCard);
pstmt3.setInt(4, change);
pstmt.executeUpdate();
}
catch (SQLException ex) {
}
catch(NumberFormatException a){
JOptionPane.showMessageDialog(this, "Invalid input", "Error!", JOptionPane.ERROR_MESSAGE);
}
}
catch(ClassNotFoundException ex) {
System.out.println("Error: unable to load driver class!");
System.exit(1);
}
catch(NumberFormatException a){
JOptionPane.showMessageDialog(this, "Invalid input", "Error!", JOptionPane.ERROR_MESSAGE);
}
finally{
try{
if(pstmt!=null)
pstmt.close();
}
catch(SQLException se2){
}
try{
if(pstmt2!=null)
pstmt2.close();
}
catch(SQLException se2){
}
try{
if(pstmt3!=null)
pstmt3.close();
}
catch(SQLException se2){
}
try{
if(conn!=null)
conn.close();
}
catch(SQLException se){
}
}
}
else if(mainMenuButton.getName().equals(((Component)e.getSource()).getName())){
EmployeeMode emp = new EmployeeMode();
emp.setVisible(true);
emp.setResizable(false);
emp.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
emp.setSize(400,300);
this.setVisible(false);
}
if(creditRadioButton.isSelected()){
creditCardLabel.setVisible(true);
creditCardTextField.setVisible(true);
payment_desc = "Credit Card";
}
else if(cashRadioButton.isSelected()){
creditCardLabel.setVisible(false);
creditCardTextField.setVisible(false);
payment_desc = "Cash";
}
}
public static void main(String args[]){
fin.setVisible(true);
fin.setResizable(false);
fin.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fin.setSize(500,400);
}
}
(编者)
工作生成的代码：
String name = nameTextField.getText();
String address = addressTextField.getText();
int contact = Integer.parseInt(contactTextField.getText());
conn = DriverManager.getConnection(URL, USER, PASS);
for(int index=0;index<add.itemNum.length;index++){
String sql = "INSERT INTO ORDERS "+
"VALUES(OrderNumSeq.NEXTVAL, ?, ?)";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1,add.itemNum[index]);
pstmt.setInt(2, add.quantity[index]);
pstmt.executeUpdate();
}
String sql2 = "INSERT INTO CUSTOMER " +
"VALUES(CustNumSeq.NEXTVAL, ?, ?, ?)";
String generatedColumns[] = {"CUST_NUM"};
pstmt2 = conn.prepareStatement(sql2, generatedColumns);
pstmt2.setString(1, name);
pstmt2.setString(2, address);
pstmt2.setInt(3, contact);
pstmt2.executeUpdate();
ResultSet rs = pstmt2.getGeneratedKeys();
custNum = rs.getInt("CUST_NUM");
creditCard = Integer.parseInt(creditCardTextField.getText());
String sql3 = "INSERT INTO TRANSACTION " +
"VALUES(TransNumSeq.NEXTVAL, ?, ?, ?, ?, ?)";
pstmt3 = conn.prepareStatement(sql3);
pstmt3.setInt(1, custNum);
pstmt3.setInt(2, payment);
pstmt3.setString(3, payment_desc);
pstmt3.setInt(4, creditCard);
pstmt3.setInt(5, change);
pstmt3.executeUpdate();
解决方法:
我很确定这个sql insert语句不正确.
String sql3 = "INSERT INTO TRANSACTION " +
"VALUES(TransNumSeq.NEXTVAL, CustNumSeq.NEXTVAL, ?, ?)";
您正在将记录插入TRANSACTION并尝试在CUSTOMER(CustNumSeq.NEXTVAL)上推进序列.你应该尝试使用
//when inserting into CUSTOMER
pstmt=conn.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);
pstmt.execute();//make the insert
//and then simply grab the key
ResultSet rs = stmt.getGeneratedKeys();
if (rs.next())
id = rs.getObject(1);
请注意,并非每个JDBC驱动程序都支持返回生成的键,因此您可能必须使用一个额外的select来获取最后生成的键.
最后,您将不得不更改此部分以反映上面所做的更改
String sql3 = "INSERT INTO TRANSACTION " +
"VALUES(TransNumSeq.NEXTVAL, ?, ?, ?, ?, ?)";
pstmt3 = conn.prepareStatement(sql3);
pstmt3.setInt(1, id);
pstmt3.setInt(2, payment);
pstmt3.setString(3, payment_desc);
pstmt3.setInt(4, creditCard);
pstmt3.setInt(5, change);
标签：java,jdbc,prepared-statement,oracle-sqldeveloper 来源： https://codeday.me/bug/20191003/1848667.html