Django-1.2.1/tests/modeltests/m2m_multiple/models.py

   1 """
   2 20. Multiple many-to-many relationships between the same two tables
   3
   4 In this example, an ``Article`` can have many "primary" ``Category`` objects
   5 and many "secondary" ``Category`` objects.
   6
   7 Set ``related_name`` to designate what the reverse relationship is called.
   8 """
   9
  10 from django.db import models
  11
  12 class Category(models.Model):
  13     name = models.CharField(max_length=20)
  14     class Meta:
  15        ordering = ('name',)
  16
  17     def __unicode__(self):
  18         return self.name
  19
  20 class Article(models.Model):
  21     headline = models.CharField(max_length=50)
  22     pub_date = models.DateTimeField()
  23     primary_categories = models.ManyToManyField(Category, related_name='primary_article_set')
  24     secondary_categories = models.ManyToManyField(Category, related_name='secondary_article_set')
  25     class Meta:
  26        ordering = ('pub_date',)
  27
  28     def __unicode__(self):
  29         return self.headline
  30
  31 __test__ = {'API_TESTS':"""
  32 >>> from datetime import datetime
  33
  34 >>> c1 = Category(name='Sports')
  35 >>> c1.save()
  36 >>> c2 = Category(name='News')
  37 >>> c2.save()
  38 >>> c3 = Category(name='Crime')
  39 >>> c3.save()
  40 >>> c4 = Category(name='Life')
  41 >>> c4.save()
  42
  43 >>> a1 = Article(headline='Area man steals', pub_date=datetime(2005, 11, 27))
  44 >>> a1.save()
  45 >>> a1.primary_categories.add(c2, c3)
  46 >>> a1.secondary_categories.add(c4)
  47
  48 >>> a2 = Article(headline='Area man runs', pub_date=datetime(2005, 11, 28))
  49 >>> a2.save()
  50 >>> a2.primary_categories.add(c1, c2)
  51 >>> a2.secondary_categories.add(c4)
  52
  53 >>> a1.primary_categories.all()
  54 [<Category: Crime>, <Category: News>]
  55
  56 >>> a2.primary_categories.all()
  57 [<Category: News>, <Category: Sports>]
  58
  59 >>> a1.secondary_categories.all()
  60 [<Category: Life>]
  61
  62
  63 >>> c1.primary_article_set.all()
  64 [<Article: Area man runs>]
  65 >>> c1.secondary_article_set.all()
  66 []
  67 >>> c2.primary_article_set.all()
  68 [<Article: Area man steals>, <Article: Area man runs>]
  69 >>> c2.secondary_article_set.all()
  70 []
  71 >>> c3.primary_article_set.all()
  72 [<Article: Area man steals>]
  73 >>> c3.secondary_article_set.all()
  74 []
  75 >>> c4.primary_article_set.all()
  76 []
  77 >>> c4.secondary_article_set.all()
  78 [<Article: Area man steals>, <Article: Area man runs>]
  79 """}