通过数据库验证登录代码

const mysql = require('mysql');

// 创建数据库连接
const connection = mysql.createConnection({
  host: 'localhost',
  user: 'your_username',
  password: 'your_password',
  database: 'your_database'
});

// 连接数据库
connection.connect();

// 用户登录函数
function login(username, password) {
  return new Promise((resolve, reject) => {
    const query = 'SELECT * FROM users WHERE username = ? AND password = ?';
    connection.query(query, [username, password], (error, results) => {
      if (error) {
        reject(error);
      } else {
        resolve(results);
      }
    });
  });
}

// 示例调用
login('testuser', 'testpassword')
  .then(results => {
    if (results.length > 0) {
      console.log('登录成功');
    } else {
      console.log('用户名或密码错误');
    }
  })
  .catch(error => {
    console.error('数据库查询失败:', error);
  });

// 关闭数据库连接
connection.end();