title: One to One field Django Admin
body: <p><em>Edited to use a one-to-one field</em></p>
  <p>I'd like to add the area of a building to a django modeladmin.  The table structure is</p>
  <pre class="lang-py prettyprint-override"><code>class Area(models.Model):
      id= models.IntegerField('Buildings', db_column='id')
      area=models.FloatField(blank=True, null=True)
  
  class Buildings(models.Model):
      id = models.AutoField(primary_key=True)
      auto_sf = models.OneToOneField(Area, db_column='id')
  </code></pre>
  <p>I know that I can access the area attribute by using</p>
  <pre><code>b=buildings.get(id=1)
  print(b.area.area)
  </code></pre>
  <p>But I don't understand how to incorporate b.area.area into the modeladmin - since this doesn't work.</p>
  <pre><code>class AdminSection(admin.ModelAdmin):
          
      def area(self, obj):
             return obj.area.area
  
      fields=(('id','area'))
  </code></pre>