自v4.0.0起，必须明确提供方言-错误

Question

我正在研究锁定Angular路由（https://catalin.me/role-based-authentication-with-angular-express-jwt-mysql-part-1/）的教程，但遇到一个错误：“从v4.0.0开始，必须明确提供方言”。我已经阅读了SO以及Web上其他地方的各种文档，但是这些建议似乎都不适用于此实例。有什么建议吗？

我的代码如下：

config.js（请注意方言在第17行）

// app/config.js

// Application configuration.
'use strict';

var config = module.exports;

config.db = {
    user: 'username',
    password: 'password',
    name: 'users'
};

config.db.details = {
    host: 'mysaldatabase',
    port: 3306,
    dialect: 'mysql'
};

config.keys = {
    secret: '/jVdfUX+u/Kn3qPY4+ahjwQgyV5UhkM5cdh1i2xhozE=' // Not anymore...
};

database.js（这是新的Sequelize发挥作用的地方）

// app/services/database.js

'use strict';

var config = require('./../config'),
    Sequelize = require('sequelize');

module.exports = new Sequelize(
    config.db.id,
    config.db.user,
    config.db.password,
    config.db.email
);

user.js

// app/models/user.js

// The User model.
"use strict";

var Sequelize = require("sequelize"),
  bcrypt = require("bcrypt");

var config = require("../config"),
  db = require("../services/database");

// 1: The model schema.
var modelDefinition = {
  username: {
    type: Sequelize.STRING,
    unique: true,
    allowNull: false
  },

  password: {
    type: Sequelize.STRING,
    allowNull: false
  }
};

// 2: The model options.
var modelOptions = {
  instanceMethods: {
    comparePasswords: comparePasswords
  },
  hooks: {
    beforeValidate: hashPassword
  }
};

// 3: Define the User model.
var UserModel = db.define("user", modelDefinition, modelOptions);

// Compares two passwords.
function comparePasswords(password, callback) {
  bcrypt.compare(password, this.password, function(error, isMatch) {
    if (error) {
      return callback(error);
    }
    return callback(null, isMatch);
  });
}

// Hashes the password for a user object.
function hashPassword(user) {
  if(user.changed('password')) {
      return bcrypt.hash(user.password, 10).then(function(password) {
          user.password = password;
      });
  }
}

module.exports = UserModel;

server.js

'use strict';

// 1: NPM dependencies.
var express = require('express'),
    bodyParser = require('body-parser'),
    morgan = require('morgan'),
    sequelize = require('sequelize'),
    passport = require('passport'),
    jwt = require('jsonwebtoken');

// 2: App related modules.
var hookJWTStrategy = require('./services/passportStrategy');


// 3: Initializations.
var app = express();

// 4: Parse as urlencoded and json.
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());

// 5: Hook up the HTTP logger.
app.use(morgan('dev'));

// 6: Hook up Passport.
app.use(passport.initialize());
// Hook the passport JWT strategy.
hookJWTStrategy(passport);

// 7: Set the static files location.
app.use(express.static(__dirname + '../../public'));

// 8: Home route.
app.get('/', function(req, res) {
    res.send('Nice meeting you wizard, I\'m Gandalf!');
});

// 9: Start the server.
app.listen('8080', function() {
    console.log('Magic happens at http://localhost:8080/! We are all now doomed!');
});

passportStrategy.js

'use strict';

// 1: NPM dependencies.
var express = require('express'),
    bodyParser = require('body-parser'),
    morgan = require('morgan'),
    sequelize = require('sequelize'),
    passport = require('passport'),
    jwt = require('jsonwebtoken');

// 2: App related modules.
var hookJWTStrategy = require('./services/passportStrategy');


// 3: Initializations.
var app = express();

// 4: Parse as urlencoded and json.
app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());

// 5: Hook up the HTTP logger.
app.use(morgan('dev'));

// 6: Hook up Passport.
app.use(passport.initialize());
// Hook the passport JWT strategy.
hookJWTStrategy(passport);

// 7: Set the static files location.
app.use(express.static(__dirname + '../../public'));

// 8: Home route.
app.get('/', function(req, res) {
    res.send('Nice meeting you wizard, I\'m Gandalf!');
});

// 9: Start the server.
app.listen('8080', function() {
    console.log('Magic happens at http://localhost:8080/! We are all now doomed!');
});