apps/catalogue/migrations/0008_fix_shelf_book_count.py

   1 # -*- coding: utf-8 -*-
   2
   3 from south.db import db
   4 from django.db import models
   5 from catalogue.models import Tag, Book
   6
   7 class Migration:
   8
   9     def forwards(self):
  10         "Write your forwards migration here"
  11         for tag in Tag.objects.filter(user__isnull=False):
  12             books = Tag.intermediary_table_model.objects.get_intersection_by_model(Book, [tag])
  13             tag.book_count = len(books)
  14             tag.save()
  15
  16     def backwards(self, orm):
  17         "Write your backwards migration here"
  18         pass