title: Can I create a mutator for a table field that doesn't exist?
body: <h2>Question</h2>
  
  <p>In Laravel 4, say I have 2 models <code>Post</code> and <code>Comment</code> with a one-to-many relationship. I would like to be able to do...</p>
  
  <pre><code>Post::create(['post_title' =&gt; 'foo',
                 'comment' =&gt; ['text' =&gt; 'Some comment']);
  </code></pre>
  
  <p>...and for this to create the post record <em>as well as</em> a new comment record. This is my attempt:-</p>
  
  <h2>My Attempt</h2>
  
  <pre><code>class Post extends Model {
  
    // Make all field mutable
    public static $unguarded = true;
  
    // Create relationship
    public function comments() {
        return $this-&gt;hasMany('Comment');
    }
  
    // Setter for comment
    public function setComment($comment) {
        $this-&gt;comments()-&gt;create($comment);
        return FALSE;
    }
  }
  </code></pre>
  
  <h2>Error</h2>
  
  <p>But I get the error:-</p>
  
  <pre><code>Column not found: 1054 Unknown column 'comment' in 'field list'
  </code></pre>
  
  <p>Is it possible to get Laravel to not look for the field? I tried returning <code>FALSE</code> from the setter but that doesn't seem to work.</p>
  
  <p>Any help much appreciated.</p>