添加具有已排序的主键和外键JDBC的列的行
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); } }
（已编辑）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();
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);
1）我没有看到您在代码中维护任何事务。
2）如果最后一个插入中有任何错误，您将无法在第3个表中看到数据。 插入第三个表时检查日志是否有exception。
3）对我来说很明显的问题是：
"INSERT INTO TRANSACTION " + "VALUES(TransNumSeq.NEXTVAL, **CustNumSeq.NEXTVAL**, ?, ?, ?, ?)"
…您正在第二次调用序列，它将具有与您在第一个语句中插入的不同的cust_no。
4）如果您在事务表中将cust_num定义为外键，则代码应该中断。 因为尚未在customer表中存在此cust_num。