old_contents: from __future__ import unicode_literals
  
  # Create your models here.
  
  
  from django.db.models import Model, CharField, DateTimeField
  
  
  class Subscription(Model):
      platform = CharField(max_length=50, choices=(
          ("email", "Email"),
          ("twitter", "Twitter"),
      ))
      platform_identifier = CharField(max_length=255)
      created_at = DateTimeField(auto_now_add=True)
      updated_at = DateTimeField(auto_now=True)
  
      class Meta:
          unique_together = ("platform", "platform_identifier")
  
      def __unicode__(self):
          return "platform: {} | platform_identifier: {} | created_at: {} | updated_at: {}".format(self.platform, self.platform_identifier, self.created_at, self.updated_at)
  
new_contents: from __future__ import unicode_literals
  
  # Create your models here.
  
  
  from django.db.models import Model, CharField, DateTimeField
  
  
  class Subscription(Model):
      platform = CharField(max_length=50, choices=(
          ("email", "Email"),
          ("facebook", "Facebook"),
      ))
      platform_identifier = CharField(max_length=255)
      created_at = DateTimeField(auto_now_add=True)
      updated_at = DateTimeField(auto_now=True)
  
      class Meta:
          unique_together = ("platform", "platform_identifier")
  
      def __unicode__(self):
          return "platform: {} | platform_identifier: {} | created_at: {} | updated_at: {}".format(self.platform, self.platform_identifier, self.created_at, self.updated_at)
  
subject: update subscription platform