title: Django model foreign key in the same table
body: <p>Before to send this kind of modification to my database, I just would like to know if what I do is OK or not.</p>
  
  <pre><code>class Comments(models.Model):
      text = models.CharField(max_length=300, null=False)
      image = models.FileField(upload_to=user_directory_path_comments, validators=[validate_file_extension], blank=True, null=True)
      articles = models.ForeignKey(Articles, verbose_name="Article", null=False)
      author = models.ForeignKey(User, verbose_name="Auteur")
      in_answer_to = models.ForeignKey(Comments, verbose_name="En réponse au commentaire", blank=True, null=True)
      date = models.DateTimeField(auto_now_add=True, auto_now=False, verbose_name="Date de création")
      update = models.DateTimeField(auto_now=True, verbose_name="Dernière modification")
  
      def __str__(self):
          return self.text
  </code></pre>
  
  <p>I have a model called Comments for listing the comments in my article's blog. I want to add the functionality to answer to a comment and so I add a field name where, if it's an answer, I add the ID of the comment.</p>
  
  <p>So, is it OK if I add a foreign key field, knowing that it's is about the same table ? This is not really a foreign key ?</p>