使用java在不使用Key#id的情况下更新了数据存储区

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class DataUpdater {
    public static void main(String[] args) {
        // 连接数据库
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "username", "password");
            
            // 构建更新数据的SQL语句
            String sql = "UPDATE mytable SET column1 = ?, column2 = ? WHERE username = ?";
            
            // 创建PreparedStatement对象
            PreparedStatement statement = connection.prepareStatement(sql);
            
            // 设置更新的参数值
            statement.setString(1, "new value 1");
            statement.setString(2, "new value 2");
            statement.setString(3, "target username");
            
            // 执行更新操作
            int rowsAffected = statement.executeUpdate();
            
            // 检查更新结果
            if (rowsAffected > 0) {
                System.out.println("数据更新成功！");
            } else {
                System.out.println("未找到匹配的数据或更新失败！");
            }
            
            // 关闭PreparedStatement对象
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭数据库连接
            if (connection != null) {
                try {
                    connection.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}