from __future__ import with_statement, absolute_import from django.contrib.contenttypes.models import ContentType from django.test import TestCase from .models import (Author, Book, Reader, Qualification, Teacher, Department, TaggedItem, Bookmark, AuthorAddress, FavoriteAuthors, AuthorWithAge, BookWithYear, Person, House, Room, Employee) class PrefetchRelatedTests(TestCase): def setUp(self): self.book1 = Book.objects.create(title="Poems") self.book2 = Book.objects.create(title="Jane Eyre") self.book3 = Book.objects.create(title="Wuthering Heights") self.book4 = Book.objects.create(title="Sense and Sensibility") self.author1 = Author.objects.create(name="Charlotte", first_book=self.book1) self.author2 = Author.objects.create(name="Anne", first_book=self.book1) self.author3 = Author.objects.create(name="Emily", first_book=self.book1) self.author4 = Author.objects.create(name="Jane", first_book=self.book4) self.book1.authors.add(self.author1, self.author2, self.author3) self.book2.authors.add(self.author1) self.book3.authors.add(self.author3) self.book4.authors.add(self.author4) self.reader1 = Reader.objects.create(name="Amy") self.reader2 = Reader.objects.create(name="Belinda") self.reader1.books_read.add(self.book1, self.book4) self.reader2.books_read.add(self.book2, self.book4) def test_m2m_forward(self): with self.assertNumQueries(2): lists = [list(b.authors.all()) for b in Book.objects.prefetch_related('authors')] normal_lists = [list(b.authors.all()) for b in Book.objects.all()] self.assertEqual(lists, normal_lists) def test_m2m_reverse(self): with self.assertNumQueries(2): lists = [list(a.books.all()) for a in Author.objects.prefetch_related('books')] normal_lists = [list(a.books.all()) for a in Author.objects.all()] self.assertEqual(lists, normal_lists) def test_foreignkey_forward(self): with self.assertNumQueries(2): books = [a.first_book for a in Author.objects.prefetch_related('first_book')] normal_books = [a.first_book for a in Author.objects.all()] self.assertEqual(books, normal_books) def test_foreignkey_reverse(self): with self.assertNumQueries(2): lists = [list(b.first_time_authors.all()) for b in Book.objects.prefetch_related('first_time_authors')] self.assertQuerysetEqual(self.book2.authors.all(), [u""]) def test_survives_clone(self): with self.assertNumQueries(2): lists = [list(b.first_time_authors.all()) for b in Book.objects.prefetch_related('first_time_authors').exclude(id=1000)] def test_len(self): with self.assertNumQueries(2): qs = Book.objects.prefetch_related('first_time_authors') length = len(qs) lists = [list(b.first_time_authors.all()) for b in qs] def test_bool(self): with self.assertNumQueries(2): qs = Book.objects.prefetch_related('first_time_authors') x = bool(qs) lists = [list(b.first_time_authors.all()) for b in qs] def test_count(self): with self.assertNumQueries(2): qs = Book.objects.prefetch_related('first_time_authors') [b.first_time_authors.count() for b in qs] def test_exists(self): with self.assertNumQueries(2): qs = Book.objects.prefetch_related('first_time_authors') [b.first_time_authors.exists() for b in qs] def test_clear(self): """ Test that we can clear the behavior by calling prefetch_related() """ with self.assertNumQueries(5): with_prefetch = Author.objects.prefetch_related('books') without_prefetch = with_prefetch.prefetch_related(None) lists = [list(a.books.all()) for a in without_prefetch] def test_m2m_then_m2m(self): """ Test we can follow a m2m and another m2m """ with self.assertNumQueries(3): qs = Author.objects.prefetch_related('books__read_by') lists = [[[unicode(r) for r in b.read_by.all()] for b in a.books.all()] for a in qs] self.assertEqual(lists, [ [[u"Amy"], [u"Belinda"]], # Charlotte - Poems, Jane Eyre [[u"Amy"]], # Anne - Poems [[u"Amy"], []], # Emily - Poems, Wuthering Heights [[u"Amy", u"Belinda"]], # Jane - Sense and Sense ]) def test_overriding_prefetch(self): with self.assertNumQueries(3): qs = Author.objects.prefetch_related('books', 'books__read_by') lists = [[[unicode(r) for r in b.read_by.all()] for b in a.books.all()] for a in qs] self.assertEqual(lists, [ [[u"Amy"], [u"Belinda"]], # Charlotte - Poems, Jane Eyre [[u"Amy"]], # Anne - Poems [[u"Amy"], []], # Emily - Poems, Wuthering Heights [[u"Amy", u"Belinda"]], # Jane - Sense and Sense ]) with self.assertNumQueries(3): qs = Author.objects.prefetch_related('books__read_by', 'books') lists = [[[unicode(r) for r in b.read_by.all()] for b in a.books.all()] for a in qs] self.assertEqual(lists, [ [[u"Amy"], [u"Belinda"]], # Charlotte - Poems, Jane Eyre [[u"Amy"]], # Anne - Poems [[u"Amy"], []], # Emily - Poems, Wuthering Heights [[u"Amy", u"Belinda"]], # Jane - Sense and Sense ]) def test_get(self): """ Test that objects retrieved with .get() get the prefetch behavior. """ # Need a double with self.assertNumQueries(3): author = Author.objects.prefetch_related('books__read_by').get(name="Charlotte") lists = [[unicode(r) for r in b.read_by.all()] for b in author.books.all()] self.assertEqual(lists, [[u"Amy"], [u"Belinda"]]) # Poems, Jane Eyre def test_foreign_key_then_m2m(self): """ Test we can follow an m2m relation after a relation like ForeignKey that doesn't have many objects """ with self.assertNumQueries(2): qs = Author.objects.select_related('first_book').prefetch_related('first_book__read_by') lists = [[unicode(r) for r in a.first_book.read_by.all()] for a in qs] self.assertEqual(lists, [[u"Amy"], [u"Amy"], [u"Amy"], [u"Amy", "Belinda"]]) def test_attribute_error(self): qs = Reader.objects.all().prefetch_related('books_read__xyz') with self.assertRaises(AttributeError) as cm: list(qs) self.assertTrue('prefetch_related' in str(cm.exception)) def test_invalid_final_lookup(self): qs = Book.objects.prefetch_related('authors__name') with self.assertRaises(ValueError) as cm: list(qs) self.assertTrue('prefetch_related' in str(cm.exception)) self.assertTrue("name" in str(cm.exception)) class DefaultManagerTests(TestCase): def setUp(self): self.qual1 = Qualification.objects.create(name="BA") self.qual2 = Qualification.objects.create(name="BSci") self.qual3 = Qualification.objects.create(name="MA") self.qual4 = Qualification.objects.create(name="PhD") self.teacher1 = Teacher.objects.create(name="Mr Cleese") self.teacher2 = Teacher.objects.create(name="Mr Idle") self.teacher3 = Teacher.objects.create(name="Mr Chapman") self.teacher1.qualifications.add(self.qual1, self.qual2, self.qual3, self.qual4) self.teacher2.qualifications.add(self.qual1) self.teacher3.qualifications.add(self.qual2) self.dept1 = Department.objects.create(name="English") self.dept2 = Department.objects.create(name="Physics") self.dept1.teachers.add(self.teacher1, self.teacher2) self.dept2.teachers.add(self.teacher1, self.teacher3) def test_m2m_then_m2m(self): with self.assertNumQueries(3): # When we prefetch the teachers, and force the query, we don't want # the default manager on teachers to immediately get all the related # qualifications, since this will do one query per teacher. qs = Department.objects.prefetch_related('teachers') depts = "".join(["%s department: %s\n" % (dept.name, ", ".join(unicode(t) for t in dept.teachers.all())) for dept in qs]) self.assertEqual(depts, "English department: Mr Cleese (BA, BSci, MA, PhD), Mr Idle (BA)\n" "Physics department: Mr Cleese (BA, BSci, MA, PhD), Mr Chapman (BSci)\n") class GenericRelationTests(TestCase): def setUp(self): book1 = Book.objects.create(title="Winnie the Pooh") book2 = Book.objects.create(title="Do you like green eggs and spam?") book3 = Book.objects.create(title="Three Men In A Boat") reader1 = Reader.objects.create(name="me") reader2 = Reader.objects.create(name="you") reader3 = Reader.objects.create(name="someone") book1.read_by.add(reader1, reader2) book2.read_by.add(reader2) book3.read_by.add(reader3) self.book1, self.book2, self.book3 = book1, book2, book3 self.reader1, self.reader2, self.reader3 = reader1, reader2, reader3 def test_prefetch_GFK(self): TaggedItem.objects.create(tag="awesome", content_object=self.book1) TaggedItem.objects.create(tag="great", content_object=self.reader1) TaggedItem.objects.create(tag="stupid", content_object=self.book2) TaggedItem.objects.create(tag="amazing", content_object=self.reader3) # 1 for TaggedItem table, 1 for Book table, 1 for Reader table with self.assertNumQueries(3): qs = TaggedItem.objects.prefetch_related('content_object') list(qs) def test_traverse_GFK(self): """ Test that we can traverse a 'content_object' with prefetch_related() and get to related objects on the other side (assuming it is suitably filtered) """ TaggedItem.objects.create(tag="awesome", content_object=self.book1) TaggedItem.objects.create(tag="awesome", content_object=self.book2) TaggedItem.objects.create(tag="awesome", content_object=self.book3) TaggedItem.objects.create(tag="awesome", content_object=self.reader1) TaggedItem.objects.create(tag="awesome", content_object=self.reader2) ct = ContentType.objects.get_for_model(Book) # We get 3 queries - 1 for main query, 1 for content_objects since they # all use the same table, and 1 for the 'read_by' relation. with self.assertNumQueries(3): # If we limit to books, we know that they will have 'read_by' # attributes, so the following makes sense: qs = TaggedItem.objects.filter(content_type=ct, tag='awesome').prefetch_related('content_object__read_by') readers_of_awesome_books = set([r.name for tag in qs for r in tag.content_object.read_by.all()]) self.assertEqual(readers_of_awesome_books, set(["me", "you", "someone"])) def test_nullable_GFK(self): TaggedItem.objects.create(tag="awesome", content_object=self.book1, created_by=self.reader1) TaggedItem.objects.create(tag="great", content_object=self.book2) TaggedItem.objects.create(tag="rubbish", content_object=self.book3) with self.assertNumQueries(2): result = [t.created_by for t in TaggedItem.objects.prefetch_related('created_by')] self.assertEqual(result, [t.created_by for t in TaggedItem.objects.all()]) def test_generic_relation(self): b = Bookmark.objects.create(url='http://www.djangoproject.com/') t1 = TaggedItem.objects.create(content_object=b, tag='django') t2 = TaggedItem.objects.create(content_object=b, tag='python') with self.assertNumQueries(2): tags = [t.tag for b in Bookmark.objects.prefetch_related('tags') for t in b.tags.all()] self.assertEqual(sorted(tags), ["django", "python"]) class MultiTableInheritanceTest(TestCase): def setUp(self): self.book1 = BookWithYear.objects.create( title="Poems", published_year=2010) self.book2 = BookWithYear.objects.create( title="More poems", published_year=2011) self.author1 = AuthorWithAge.objects.create( name='Jane', first_book=self.book1, age=50) self.author2 = AuthorWithAge.objects.create( name='Tom', first_book=self.book1, age=49) self.author3 = AuthorWithAge.objects.create( name='Robert', first_book=self.book2, age=48) self.authorAddress = AuthorAddress.objects.create( author=self.author1, address='SomeStreet 1') self.book2.aged_authors.add(self.author2, self.author3) def test_foreignkey(self): with self.assertNumQueries(2): qs = AuthorWithAge.objects.prefetch_related('addresses') addresses = [[unicode(address) for address in obj.addresses.all()] for obj in qs] self.assertEquals(addresses, [[unicode(self.authorAddress)], [], []]) def test_m2m_to_inheriting_model(self): qs = AuthorWithAge.objects.prefetch_related('books_with_year') with self.assertNumQueries(2): lst = [[unicode(book) for book in author.books_with_year.all()] for author in qs] qs = AuthorWithAge.objects.all() lst2 = [[unicode(book) for book in author.books_with_year.all()] for author in qs] self.assertEquals(lst, lst2) qs = BookWithYear.objects.prefetch_related('aged_authors') with self.assertNumQueries(2): lst = [[unicode(author) for author in book.aged_authors.all()] for book in qs] qs = BookWithYear.objects.all() lst2 = [[unicode(author) for author in book.aged_authors.all()] for book in qs] self.assertEquals(lst, lst2) def test_parent_link_prefetch(self): with self.assertNumQueries(2): [a.author for a in AuthorWithAge.objects.prefetch_related('author')] def test_child_link_prefetch(self): with self.assertNumQueries(2): l = [a.authorwithage for a in Author.objects.prefetch_related('authorwithage')] self.assertEqual(l, [a.authorwithage for a in Author.objects.all()]) class ForeignKeyToFieldTest(TestCase): def setUp(self): self.book = Book.objects.create(title="Poems") self.author1 = Author.objects.create(name='Jane', first_book=self.book) self.author2 = Author.objects.create(name='Tom', first_book=self.book) self.author3 = Author.objects.create(name='Robert', first_book=self.book) self.authorAddress = AuthorAddress.objects.create( author=self.author1, address='SomeStreet 1' ) FavoriteAuthors.objects.create(author=self.author1, likes_author=self.author2) FavoriteAuthors.objects.create(author=self.author2, likes_author=self.author3) FavoriteAuthors.objects.create(author=self.author3, likes_author=self.author1) def test_foreignkey(self): with self.assertNumQueries(2): qs = Author.objects.prefetch_related('addresses') addresses = [[unicode(address) for address in obj.addresses.all()] for obj in qs] self.assertEquals(addresses, [[unicode(self.authorAddress)], [], []]) def test_m2m(self): with self.assertNumQueries(3): qs = Author.objects.all().prefetch_related('favorite_authors', 'favors_me') favorites = [( [unicode(i_like) for i_like in author.favorite_authors.all()], [unicode(likes_me) for likes_me in author.favors_me.all()] ) for author in qs] self.assertEquals( favorites, [ ([unicode(self.author2)],[unicode(self.author3)]), ([unicode(self.author3)],[unicode(self.author1)]), ([unicode(self.author1)],[unicode(self.author2)]) ] ) class LookupOrderingTest(TestCase): """ Test cases that demonstrate that ordering of lookups is important, and ensure it is preserved. """ def setUp(self): self.person1 = Person.objects.create(name="Joe") self.person2 = Person.objects.create(name="Mary") self.house1 = House.objects.create(address="123 Main St") self.house2 = House.objects.create(address="45 Side St") self.house3 = House.objects.create(address="6 Downing St") self.house4 = House.objects.create(address="7 Regents St") self.room1_1 = Room.objects.create(name="Dining room", house=self.house1) self.room1_2 = Room.objects.create(name="Lounge", house=self.house1) self.room1_3 = Room.objects.create(name="Kitchen", house=self.house1) self.room2_1 = Room.objects.create(name="Dining room", house=self.house2) self.room2_2 = Room.objects.create(name="Lounge", house=self.house2) self.room3_1 = Room.objects.create(name="Dining room", house=self.house3) self.room3_2 = Room.objects.create(name="Lounge", house=self.house3) self.room3_3 = Room.objects.create(name="Kitchen", house=self.house3) self.room4_1 = Room.objects.create(name="Dining room", house=self.house4) self.room4_2 = Room.objects.create(name="Lounge", house=self.house4) self.person1.houses.add(self.house1, self.house2) self.person2.houses.add(self.house3, self.house4) def test_order(self): with self.assertNumQueries(4): # The following two queries must be done in the same order as written, # otherwise 'primary_house' will cause non-prefetched lookups qs = Person.objects.prefetch_related('houses__rooms', 'primary_house__occupants') [list(p.primary_house.occupants.all()) for p in qs] class NullableTest(TestCase): def setUp(self): boss = Employee.objects.create(name="Peter") worker1 = Employee.objects.create(name="Joe", boss=boss) worker2 = Employee.objects.create(name="Angela", boss=boss) def test_traverse_nullable(self): # Because we use select_related() for 'boss', it doesn't need to be # prefetched, but we can still traverse it although it contains some nulls with self.assertNumQueries(2): qs = Employee.objects.select_related('boss').prefetch_related('boss__serfs') co_serfs = [list(e.boss.serfs.all()) if e.boss is not None else [] for e in qs] qs2 = Employee.objects.select_related('boss') co_serfs2 = [list(e.boss.serfs.all()) if e.boss is not None else [] for e in qs2] self.assertEqual(co_serfs, co_serfs2) def test_prefetch_nullable(self): # One for main employee, one for boss, one for serfs with self.assertNumQueries(3): qs = Employee.objects.prefetch_related('boss__serfs') co_serfs = [list(e.boss.serfs.all()) if e.boss is not None else [] for e in qs] qs2 = Employee.objects.all() co_serfs2 = [list(e.boss.serfs.all()) if e.boss is not None else [] for e in qs2] self.assertEqual(co_serfs, co_serfs2) def test_in_bulk(self): """ In-bulk does correctly prefetch objects by not using .iterator() directly. """ boss1 = Employee.objects.create(name="Peter") boss2 = Employee.objects.create(name="Jack") with self.assertNumQueries(2): # Check that prefetch is done and it does not cause any errors. bulk = Employee.objects.prefetch_related('serfs').in_bulk([boss1.pk, boss2.pk]) for b in bulk.values(): list(b.serfs.all())