UnhandledPromiseRejectionWarning：TypeError：无法读取未定义的属性“密码”

Question

这是我的登录代码。比较用户输入的密码和存储的密码时出现未处理的承诺。

exports.login = (req, res) => {
  try {    
    const {email, password} = req.body
    console.log(req.body)

    if(!email || !password) {
      return res.status(400).render('login', {
        message: 'Please Provide an email and password'
      })
    }

    db.query('SELECT * FROM users WHERE email = ? ',{email}, async (error, results) => {
        console.log(error)
        console.log(results)
        if( !results || !(await bcrypt.compare(password, results[0].password)) ) {
          res.status(401).render('login', {
            message: 'Email or Password is Incorrect'
          })
      }
     })

  } catch (error) {
    console.log(error)
  }
}

Console.log(error) 为空..

更新

Answer 1

我建议你promisifydb.query 这样你就可以await 它，错误将被正确地捕获在catch 块中，并且你的代码将被展平。

您的错误是由results[0] 引起的，即undefined 在尝试访问其password 属性时，这意味着results 是一个空数组。

query 的第二个参数不应该是Object，而是Array，所以将{ email } 替换为[email]：

const {
    promisify
} = require('util');

const query = promisify(db.query.bind(db));

exports.login = async (req, res) => {
    try {
        const {
            email,
            password
        } = req.body;

        if (!email || !password) {
            return res.status(400).render('login', {
                message: 'Please Provide an email and password'
            });
        }

        const results = await query('SELECT * FROM users WHERE email = ? ', [email]); // problem occur due to usage of curly brackets.
            
        if (!results || !(await bcrypt.compare(password, results[0].password))) {
            res.status(401).render('login', {
                message: 'Email or Password is Incorrect'
            });
        }

    } catch (error) {
        console.log(error);
    }
}