title: Sequelize Eager Loading not working at all
body: <p>First of all, I already searched every single question about this topic here in StackOverflow and in almost everywhere, so I'm asking if you can help me.</p>
  
  <p>I'm making a web app using ExpressJS(v4.15.5) and Sequelize(v4.22.6). I defined the models, migrations, associations and inclusively add an alias to all associations so I'll use this alias when making the eager loading. If I try to eager load a specific association tells me that <strong>X</strong> is not associated to <strong>Y</strong> and of course, if I try to eager load all associations using <code>{include: [{all: true}]}</code> it doesn't return any association.</p>
  
  <p>I already verified if the <strong>sync</strong> was being done and it is, in file <code>bin/www</code>:</p>
  
  <pre><code>models.sequelize.sync().then(function() {
      /**
       * Listen on provided port, on all network interfaces.
       */
      server.listen(port, function() {
          debug('Express server listening on port ' + server.address().port);
      });
      server.on('error', onError);
      server.on('listening', onListening);
  });
  </code></pre>
  
  <p>Above are my models <strong>MessageGroup</strong> and <strong>Message</strong> and my <strong>routes/index.js</strong> file.</p>
  
  <p><strong>MessageGroup Model</strong></p>
  
  <pre><code>'use strict';
  
  module.exports = (sequelize, DataTypes) =&gt; {
      var MessageGroup = sequelize.define('MessageGroup', {
          slug: DataTypes.STRING,
          name: DataTypes.STRING
      }, {
          classMethods: {
              associate: function (models) {
                  // associations can be defined here
                  MessageGroup.hasMany(models.Message, { as:'messages', foreignKey: "messageGroupId" });
              }
          }
      });
  
      return MessageGroup;
  };
  </code></pre>
  
  <p><strong>Message model</strong>
  </p>
  
  <pre><code>'use strict';
  
  module.exports = (sequelize, DataTypes) =&gt; {
      var Message = sequelize.define('Message', {
          slug: DataTypes.STRING,
          name: DataTypes.STRING,
          description: DataTypes.TEXT
      }, {
          classMethods: {
              associate: function (models) {
                  // associations can be defined here
                  Message.belongsTo(models.MessageGroup, { as:'messageGroup', foreignKey: "messageGroupId" });
                  Message.hasMany(models.MessageParameter, { as:'messageParameters', foreignKey: "messageId" });
              }
          }
      });
  
      return Message;
  };
  </code></pre>
  
  <p><strong>routes/index.js file</strong></p>
  
  <pre><code>&lt;!-- language: javascript --&gt;
  const express = require('express');
  const router = express.Router();
  const models = require('../models');
  
  router.get('/data', function (req, res, next) {
      models.MessageGroup.findAll({include: [{all: true}]}).then(result =&gt; {
          res.json({data: result});
      });
  });
  
  
  module.exports = router;
  </code></pre>
  
  <p>Thanks in advance.</p>