1 from django.db import models

     2 from django.contrib.auth.models import *

     3 

     4 

     5 class Owner(models.Model):

     6     user = models.ForeignKey(User,  blank=True, null=True)

     7     group = models.ForeignKey(Group,  blank=True, null=True)

     8 

     9     def __unicode__(self):

    10         if self.user:

    11             return self.user.username

    12         else:

    13             return self.group.name

    14 

    15 

    16 class Document(models.Model):

    17     owner= models.ForeignKey(Owner, blank = True, null=True)

    18 

    19     class Meta:

    20         abstract = True

    21 

    22