title: Annotate query set with field value
body: <p>Multilanguage website with translations stored in columns of one table.
  Need to pass query set to template with already filtered translations.
  Language variable is stored in session.</p>
  
  <pre><code>class Item(models.Model):
      name = models.CharField(max_length=128)
      description = models.ForeignKey(Localization)
  
  class Localization(models.Model):
      klingon = models.TextField(blank=True, null=True, verbose_name='klingon')
      english = models.TextField(blank=True, null=True, verbose_name='english')
  </code></pre>
  
  <p>Thought would be nice just to annotate the qs with the needed text, however I failed to find how to annotate with a field value. Something like </p>
  
  <pre><code>item = Item.objects.all().annotate(text=description.klingon)
  </code></pre>
  
  <p>Another approach would be to use a template filter like </p>
  
  <pre><code>item.description|choose_lang:request
  </code></pre>
  
  <p>but sorting the qs before the template seems neater.</p>