关于jdbc中数据的修改问题

Question

package expressdelivery.frame;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.*;
import javax.swing.*;

import expressdelivery.dao.Conn;

public class ModifyInfoFrame extends JFrame {

    private JLabel l_id, l_rname, l_addr, l_tel, l_sname, l_state;
    private JTextField t_id, t_rname, t_addr, t_tel, t_sname;
    private JComboBox<String> c_state;
    private JButton b_add, b_reset;
    
    public ModifyInfoFrame(String id) {
        this.setSize(300, 350);
        this.setLocation(350, 300);
        this.setTitle("添加商品信息");
        init(id);
        this.setVisible(true);
    }
    
    public void init(String id) {
        this.setLayout(new GridLayout(7, 2, 10, 10));
        l_id = new JLabel("快递编号", JLabel.CENTER);
        l_rname = new JLabel("收件人", JLabel.CENTER);
        l_addr = new JLabel("收件地址", JLabel.CENTER);
        l_tel = new JLabel("收件人电话", JLabel.CENTER);
        l_sname = new JLabel("派送人", JLabel.CENTER);
        l_state = new JLabel("派送状态", JLabel.CENTER);
        
        t_id = new JTextField();
        t_rname = new JTextField();
        t_addr = new JTextField();
        t_tel = new JTextField();
        t_sname = new JTextField();
        
        c_state = new JComboBox<String>();
        c_state.addItem("请选择");
        c_state.addItem("未开始派送");
        c_state.addItem("正在派送中");
        c_state.addItem("已签收");
        
        b_add = new JButton("添加");
        b_add.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                String id = t_id.getText();
                String rname = t_rname.getText();
                String addr = t_addr.getText();
                String tel = t_tel.getText();
                String sname = t_sname.getText();   
                String state = (String) c_state.getSelectedItem();
                try {
                    Conn c = new Conn();
                    Connection con = c.getConnection();
                    PreparedStatement sql = con.prepareStatement("update courier set *" + "=? where id =" + id);
                    sql.setString(1,id);
                    sql.setString(2,rname);
                    sql.setString(3,addr);
                    sql.setString(4,tel);
                    sql.setString(5,sname);
                    sql.setString(6,state);
                    sql.executeUpdate();
                } catch (SQLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
                try {
                    new ManagerInfoFrame();
                } catch (SQLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
                dispose();
            }
            
        });
        b_reset = new JButton("清空");
        b_reset.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                // TODO Auto-generated method stub
                t_id.setText("");
                t_rname.setText("");
                t_addr.setText("");
                t_tel.setText("");
                t_sname.setText("");
            }
            
        });
        
        this.add(l_id);
        this.add(t_id);
        
        this.add(l_rname);
        this.add(t_rname);
        
        this.add(l_addr);
        this.add(t_addr);
        
        this.add(l_tel);
        this.add(t_tel);
        
        this.add(l_sname);
        this.add(t_sname);
        
        this.add(l_state);
        this.add(c_state);
        
        this.add(b_add);
        this.add(b_reset);
        
    }
}

运行结果经常出现

Answer 1

63行的update语句写错了，update不能写set * ,要把你需要更新的字段都写上，如 update 表名 set 字段1=?,字段2=?这样