Javascript 无法使用NodeJS、Express连接到MySQL

我试图使用express for server通过nodeJS应用程序连接到MySQL，我阅读了MySQL npm文档以开始连接，但似乎我从createConnection.connect（）中编写的回调函数中得到了错误，我使用phpmyadmin只是为了查看结果和图表

这是我的密码：

const express = require('express');
const app = express();
const mysql = require('mysql'); 
require('dotenv').config();
const workers = require('./routes/workers');


app.use('/', workers);


const DB = mysql.createConnection({
    host     : 'localhost',
   user     : 'root',
  charset: 'utf8_general_ci',
  password: '',

});

DB.connect((err) => {
     throw `error: ${err}`
 });

 app.listen(process.env._PORT, () => {
     console.log(`Server is running on ${process.env._PORT}`);
 });

---

安装sequelizejs、mysql、mysql2库

var Sequelize = require('sequelize');
var sequelize = new Sequelize(dbName, username, password,{ host: localhost,
    // data type
    dialect: mysql,
});

您可以使用.authenticate（）函数测试连接是否正常：

try {
  await sequelize.authenticate();
  console.log('Connection has been established successfully.');
} catch (error) {
  console.error('Unable to connect to the database:', error);
}

---

连接后，您没有检查错误。您必须检查数据库连接时是否有任何错误，如下所示

DB.connect((err) => {
     if(err){
        throw `error: ${err}`       
     }
     console.log("Database connected successfully");
 });

---

在连接数据库时，您能分享您的错误吗？请告诉我们错误详细信息，而且我更喜欢错误：错误：connect econnrefered127.0.0.1:3306