from __future__ import absolute_import from django.test import TestCase from .models import Article, Publication class ManyToManyTests(TestCase): def setUp(self): # Create a couple of Publications. self.p1 = Publication.objects.create(id=None, title='The Python Journal') self.p2 = Publication.objects.create(id=None, title='Science News') self.p3 = Publication.objects.create(id=None, title='Science Weekly') self.p4 = Publication.objects.create(title='Highlights for Children') self.a1 = Article.objects.create(id=None, headline='Django lets you build Web apps easily') self.a1.publications.add(self.p1) self.a2 = Article.objects.create(id=None, headline='NASA uses Python') self.a2.publications.add(self.p1, self.p2, self.p3, self.p4) self.a3 = Article.objects.create(headline='NASA finds intelligent life on Earth') self.a3.publications.add(self.p2) self.a4 = Article.objects.create(headline='Oxygen-free diet works wonders') self.a4.publications.add(self.p2) def test_add(self): # Create an Article. a5 = Article(id=None, headline='Django lets you reate Web apps easily') # You can't associate it with a Publication until it's been saved. self.assertRaises(ValueError, getattr, a5, 'publications') # Save it! a5.save() # Associate the Article with a Publication. a5.publications.add(self.p1) self.assertQuerysetEqual(a5.publications.all(), ['']) # Create another Article, and set it to appear in both Publications. a6 = Article(id=None, headline='ESA uses Python') a6.save() a6.publications.add(self.p1, self.p2) a6.publications.add(self.p3) # Adding a second time is OK a6.publications.add(self.p3) self.assertQuerysetEqual(a6.publications.all(), [ '', '', '', ]) # Adding an object of the wrong type raises TypeError with self.assertRaisesRegexp(TypeError, "'Publication' instance expected, got ', '', '', '', ]) def test_reverse_add(self): # Adding via the 'other' end of an m2m a5 = Article(headline='NASA finds intelligent life on Mars') a5.save() self.p2.article_set.add(a5) self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', '', '', ]) self.assertQuerysetEqual(a5.publications.all(), ['']) # Adding via the other end using keywords new_article = self.p2.article_set.create(headline='Carbon-free diet works wonders') self.assertQuerysetEqual( self.p2.article_set.all(), [ '', '', '', '', '', ]) a6 = self.p2.article_set.all()[3] self.assertQuerysetEqual(a6.publications.all(), [ '', '', '', '', ]) def test_related_sets(self): # Article objects have access to their related Publication objects. self.assertQuerysetEqual(self.a1.publications.all(), ['']) self.assertQuerysetEqual(self.a2.publications.all(), [ '', '', '', '', ]) # Publication objects have access to their related Article objects. self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', '', ]) self.assertQuerysetEqual(self.p1.article_set.all(), [ '', '', ]) self.assertQuerysetEqual(Publication.objects.get(id=self.p4.id).article_set.all(), ['']) def test_selects(self): # We can perform kwarg queries across m2m relationships self.assertQuerysetEqual( Article.objects.filter(publications__id__exact=self.p1.id), [ '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications__pk=self.p1.id), [ '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications=self.p1.id), [ '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications=self.p1), [ '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications__title__startswith="Science"), [ '', '', '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications__title__startswith="Science").distinct(), [ '', '', '', ]) # The count() function respects distinct() as well. self.assertEqual(Article.objects.filter(publications__title__startswith="Science").count(), 4) self.assertEqual(Article.objects.filter(publications__title__startswith="Science").distinct().count(), 3) self.assertQuerysetEqual( Article.objects.filter(publications__in=[self.p1.id,self.p2.id]).distinct(), [ '', '', '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications__in=[self.p1.id,self.p2]).distinct(), [ '', '', '', '', ]) self.assertQuerysetEqual( Article.objects.filter(publications__in=[self.p1,self.p2]).distinct(), [ '', '', '', '', ]) # Excluding a related item works as you would expect, too (although the SQL # involved is a little complex). self.assertQuerysetEqual(Article.objects.exclude(publications=self.p2), ['']) def test_reverse_selects(self): # Reverse m2m queries are supported (i.e., starting at the table that # doesn't have a ManyToManyField). self.assertQuerysetEqual(Publication.objects.filter(id__exact=self.p1.id), ['']) self.assertQuerysetEqual(Publication.objects.filter(pk=self.p1.id), ['']) self.assertQuerysetEqual( Publication.objects.filter(article__headline__startswith="NASA"), [ '', '', '', '', '', ]) self.assertQuerysetEqual(Publication.objects.filter(article__id__exact=self.a1.id), ['']) self.assertQuerysetEqual(Publication.objects.filter(article__pk=self.a1.id), ['']) self.assertQuerysetEqual(Publication.objects.filter(article=self.a1.id), ['']) self.assertQuerysetEqual(Publication.objects.filter(article=self.a1), ['']) self.assertQuerysetEqual( Publication.objects.filter(article__in=[self.a1.id,self.a2.id]).distinct(), [ '', '', '', '', ]) self.assertQuerysetEqual( Publication.objects.filter(article__in=[self.a1.id,self.a2]).distinct(), [ '', '', '', '', ]) self.assertQuerysetEqual( Publication.objects.filter(article__in=[self.a1,self.a2]).distinct(), [ '', '', '', '', ]) def test_delete(self): # If we delete a Publication, its Articles won't be able to access it. self.p1.delete() self.assertQuerysetEqual(Publication.objects.all(), [ '', '', '', ]) self.assertQuerysetEqual(self.a1.publications.all(), []) # If we delete an Article, its Publications won't be able to access it. self.a2.delete() self.assertQuerysetEqual(Article.objects.all(), [ '', '', '', ]) self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', ]) def test_bulk_delete(self): # Bulk delete some Publications - references to deleted publications should go Publication.objects.filter(title__startswith='Science').delete() self.assertQuerysetEqual(Publication.objects.all(), [ '', '', ]) self.assertQuerysetEqual(Article.objects.all(), [ '', '', '', '', ]) self.assertQuerysetEqual(self.a2.publications.all(), [ '', '', ]) # Bulk delete some articles - references to deleted objects should go q = Article.objects.filter(headline__startswith='Django') self.assertQuerysetEqual(q, ['']) q.delete() # After the delete, the QuerySet cache needs to be cleared, # and the referenced objects should be gone self.assertQuerysetEqual(q, []) self.assertQuerysetEqual(self.p1.article_set.all(), ['']) def test_remove(self): # Removing publication from an article: self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', '', ]) self.a4.publications.remove(self.p2) self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', ]) self.assertQuerysetEqual(self.a4.publications.all(), []) # And from the other end self.p2.article_set.remove(self.a3) self.assertQuerysetEqual(self.p2.article_set.all(), [ '', ]) self.assertQuerysetEqual(self.a3.publications.all(), []) def test_assign(self): # Relation sets can be assigned. Assignment clears any existing set members self.p2.article_set = [self.a4, self.a3] self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', ]) self.assertQuerysetEqual(self.a4.publications.all(), ['']) self.a4.publications = [self.p3.id] self.assertQuerysetEqual(self.p2.article_set.all(), ['']) self.assertQuerysetEqual(self.a4.publications.all(), ['']) # An alternate to calling clear() is to assign the empty set self.p2.article_set = [] self.assertQuerysetEqual(self.p2.article_set.all(), []) self.a4.publications = [] self.assertQuerysetEqual(self.a4.publications.all(), []) def test_assign_ids(self): # Relation sets can also be set using primary key values self.p2.article_set = [self.a4.id, self.a3.id] self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', ]) self.assertQuerysetEqual(self.a4.publications.all(), ['']) self.a4.publications = [self.p3.id] self.assertQuerysetEqual(self.p2.article_set.all(), ['']) self.assertQuerysetEqual(self.a4.publications.all(), ['']) def test_clear(self): # Relation sets can be cleared: self.p2.article_set.clear() self.assertQuerysetEqual(self.p2.article_set.all(), []) self.assertQuerysetEqual(self.a4.publications.all(), []) # And you can clear from the other end self.p2.article_set.add(self.a3, self.a4) self.assertQuerysetEqual(self.p2.article_set.all(), [ '', '', ]) self.assertQuerysetEqual(self.a4.publications.all(), [ '', ]) self.a4.publications.clear() self.assertQuerysetEqual(self.a4.publications.all(), []) self.assertQuerysetEqual(self.p2.article_set.all(), [''])