nodeJS中查询和表达的问题

Question

我正在为带有nodeJS的服务器使用express开发一个网页。我在注册页面上，并且正在尝试验证用户插入的数据，但是当我进行查询时出现错误。

auth.js

const express = require('express');

const router = express.Router();

const { bd } = require('../database');

const help_functions = require('../lib/common');

router.post('/signup', async (req,res) => {

    const fullname = req.body['fullname'];

    const email = req.body['email'];

    const username = req.body['username'];

    const password = req.body['password'];

    const password_repeat = req.body['password_repeat'];

    var validation_msg = help_functions.validateSignUp(fullname, email, username, password, password_repeat);

    validation_msg = await help_functions.checkRepeatedUserEmail(email);

});

数据库.js

const mysql = require('mysql');

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

const database =  { // Database credentials }

const bd = mysql.createPool(database);

bd.getConnection((err,connection) => {

    if (err) {

        if (err.code === 'PROTOCOL_CONNECTION_LOST') {

            console.error('Database connection failed !');

        }

        if (err.code === 'ER_CON_COUNT_ERROR') {

            console.error('Database has too many connections !');

        }

        if (err.code === 'ECONNREFUSED') {

            console.error('Database connection was refused !');

        }

    }

    if (connection) {

        connection.release();

        console.log('Database is connected !');

        return;

    }

});

bd.query = promisify(bd.query);

module.exports = bd;

common.js

const { bd } = require('../database');

const helper_functions = {}

helper_functions.validateSignUp = (fullname, email, username, password, password_repeat) => {

    if (fullname === '' || email === '' || username === '' || password === '' || password_repeat === '') {

        return 'All the fields had to be completed!';

    }

    if (!(password.length >= 8 && (/\d/g.test(password) && (/[A-Z]/.test(password)))) ) {

        return 'The password needs to contain at least one capital letter, a number and 8 digits!';

    }

有谁知道发生了什么？？谢谢阅读！

Answer 1

您将数据库公开为默认导出database.js：module.exports = bd;但是您正在导入它，就好像它是用名称导出的一样db：const { bd } = require('../database');将导出更改database.js为：module.exports = {     bd: bd};或将其导入common.js文件中：const bd = require('../database');

Answer 2

错误说 db 没有在 common.js 文件中定义，可能是你做错了 require('../database'); 该 require 语句中有错误。使用调试器在该点停止，看看你是否在那里得到 db。