title: Sequelize LEFT JOIN only single column value
body: <p>So I have next structure: Comments, Users, Likes.</p>
  
  <p>Users has many likes, Comments has many likes.</p>
  
  <p>I'm trying to get all Comments and check if User liked them. I have a raw query with LEFT JOIN that is working totally fine:</p>
  
  <pre><code>await sequelize.query(`SELECT comments.*, likes.liked FROM comments LEFT JOIN 
  likes ON likes.commentId = comment.id AND likes.user_id = '123'`, {type: Sequelize.QueryTypes.SELECT});
  </code></pre>
  
  <p>I'm getting something like this: </p>
  
  <pre><code>    [{
          "id": 1,
          "userId": "123",
          "comment": "abcde",
          "liked": true
      },
      {
          "id": 2,
          "userId": "552",
          "comment": "abc",
          "liked": null
      }]
  </code></pre>
  
  <p>Now I'm trying to implement the same using <code>findAll()</code> method.</p>
  
  <pre><code>await Comment.findAll({
          include: [{
              model: Like,
              attributes: ['liked'],
              where: {user_id: id},
              required: false
          }]
      })
  </code></pre>
  
  <p>But I'm getting this: </p>
  
  <pre><code>[{
      "id": 1,
      "userId": "123",
      "comment": "abcde",
      "likes": [{liked:true}]
  },
  {
      "id": 2,
      "userId": "552",
      "comment": "abc",
      "likes": []
  }]
  </code></pre>
  
  <p>So the question is: How can I include only column <code>liked</code> and not array of <code>likes</code>? Thank you.</p>