from __future__ import unicode_literals from datetime import datetime import threading from django.core.exceptions import ObjectDoesNotExist, MultipleObjectsReturned from django.db import connections, DEFAULT_DB_ALIAS from django.db import DatabaseError from django.db.models.fields import Field, FieldDoesNotExist from django.db.models.manager import BaseManager from django.db.models.query import QuerySet, EmptyQuerySet, ValuesListQuerySet, MAX_GET_RESULTS from django.test import TestCase, TransactionTestCase, skipIfDBFeature, skipUnlessDBFeature from django.utils import six from django.utils.translation import ugettext_lazy from .models import Article, SelfRef, ArticleSelectOnSave class ModelTest(TestCase): def test_lookup(self): # No articles are in the system yet. self.assertQuerysetEqual(Article.objects.all(), []) # Create an Article. a = Article( id=None, headline='Area man programs in Python', pub_date=datetime(2005, 7, 28), ) # Save it into the database. You have to call save() explicitly. a.save() # Now it has an ID. self.assertTrue(a.id != None) # Models have a pk property that is an alias for the primary key # attribute (by default, the 'id' attribute). self.assertEqual(a.pk, a.id) # Access database columns via Python attributes. self.assertEqual(a.headline, 'Area man programs in Python') self.assertEqual(a.pub_date, datetime(2005, 7, 28, 0, 0)) # Change values by changing the attributes, then calling save(). a.headline = 'Area woman programs in Python' a.save() # Article.objects.all() returns all the articles in the database. self.assertQuerysetEqual(Article.objects.all(), ['']) # Django provides a rich database lookup API. self.assertEqual(Article.objects.get(id__exact=a.id), a) self.assertEqual(Article.objects.get(headline__startswith='Area woman'), a) self.assertEqual(Article.objects.get(pub_date__year=2005), a) self.assertEqual(Article.objects.get(pub_date__year=2005, pub_date__month=7), a) self.assertEqual(Article.objects.get(pub_date__year=2005, pub_date__month=7, pub_date__day=28), a) self.assertEqual(Article.objects.get(pub_date__week_day=5), a) # The "__exact" lookup type can be omitted, as a shortcut. self.assertEqual(Article.objects.get(id=a.id), a) self.assertEqual(Article.objects.get(headline='Area woman programs in Python'), a) self.assertQuerysetEqual( Article.objects.filter(pub_date__year=2005), [''], ) self.assertQuerysetEqual( Article.objects.filter(pub_date__year=2004), [], ) self.assertQuerysetEqual( Article.objects.filter(pub_date__year=2005, pub_date__month=7), [''], ) self.assertQuerysetEqual( Article.objects.filter(pub_date__week_day=5), [''], ) self.assertQuerysetEqual( Article.objects.filter(pub_date__week_day=6), [], ) # Django raises an Article.DoesNotExist exception for get() if the # parameters don't match any object. six.assertRaisesRegex(self, ObjectDoesNotExist, "Article matching query does not exist.", Article.objects.get, id__exact=2000, ) # To avoid dict-ordering related errors check only one lookup # in single assert. self.assertRaises( ObjectDoesNotExist, Article.objects.get, pub_date__year=2005, pub_date__month=8, ) six.assertRaisesRegex(self, ObjectDoesNotExist, "Article matching query does not exist.", Article.objects.get, pub_date__week_day=6, ) # Lookup by a primary key is the most common case, so Django # provides a shortcut for primary-key exact lookups. # The following is identical to articles.get(id=a.id). self.assertEqual(Article.objects.get(pk=a.id), a) # pk can be used as a shortcut for the primary key name in any query. self.assertQuerysetEqual(Article.objects.filter(pk__in=[a.id]), [""]) # Model instances of the same type and same ID are considered equal. a = Article.objects.get(pk=a.id) b = Article.objects.get(pk=a.id) self.assertEqual(a, b) # Create a very similar object a = Article( id=None, headline='Area man programs in Python', pub_date=datetime(2005, 7, 28), ) a.save() self.assertEqual(Article.objects.count(), 2) # Django raises an Article.MultipleObjectsReturned exception if the # lookup matches more than one object six.assertRaisesRegex(self, MultipleObjectsReturned, "get\(\) returned more than one Article -- it returned 2!", Article.objects.get, headline__startswith='Area', ) six.assertRaisesRegex(self, MultipleObjectsReturned, "get\(\) returned more than one Article -- it returned 2!", Article.objects.get, pub_date__year=2005, ) six.assertRaisesRegex(self, MultipleObjectsReturned, "get\(\) returned more than one Article -- it returned 2!", Article.objects.get, pub_date__year=2005, pub_date__month=7, ) def test_multiple_objects_max_num_fetched(self): """ #6785 - get() should fetch a limited number of results. """ Article.objects.bulk_create( Article(headline='Area %s' % i, pub_date=datetime(2005, 7, 28)) for i in range(MAX_GET_RESULTS) ) six.assertRaisesRegex(self, MultipleObjectsReturned, "get\(\) returned more than one Article -- it returned %d!" % MAX_GET_RESULTS, Article.objects.get, headline__startswith='Area', ) Article.objects.create(headline='Area %s' % MAX_GET_RESULTS, pub_date=datetime(2005, 7, 28)) six.assertRaisesRegex(self, MultipleObjectsReturned, "get\(\) returned more than one Article -- it returned more than %d!" % MAX_GET_RESULTS, Article.objects.get, headline__startswith='Area', ) def test_object_creation(self): # Create an Article. a = Article( id=None, headline='Area man programs in Python', pub_date=datetime(2005, 7, 28), ) # Save it into the database. You have to call save() explicitly. a.save() # You can initialize a model instance using positional arguments, # which should match the field order as defined in the model. a2 = Article(None, 'Second article', datetime(2005, 7, 29)) a2.save() self.assertNotEqual(a2.id, a.id) self.assertEqual(a2.headline, 'Second article') self.assertEqual(a2.pub_date, datetime(2005, 7, 29, 0, 0)) # ...or, you can use keyword arguments. a3 = Article( id=None, headline='Third article', pub_date=datetime(2005, 7, 30), ) a3.save() self.assertNotEqual(a3.id, a.id) self.assertNotEqual(a3.id, a2.id) self.assertEqual(a3.headline, 'Third article') self.assertEqual(a3.pub_date, datetime(2005, 7, 30, 0, 0)) # You can also mix and match position and keyword arguments, but # be sure not to duplicate field information. a4 = Article(None, 'Fourth article', pub_date=datetime(2005, 7, 31)) a4.save() self.assertEqual(a4.headline, 'Fourth article') # Don't use invalid keyword arguments. six.assertRaisesRegex(self, TypeError, "'foo' is an invalid keyword argument for this function", Article, id=None, headline='Invalid', pub_date=datetime(2005, 7, 31), foo='bar', ) # You can leave off the value for an AutoField when creating an # object, because it'll get filled in automatically when you save(). a5 = Article(headline='Article 6', pub_date=datetime(2005, 7, 31)) a5.save() self.assertEqual(a5.headline, 'Article 6') # If you leave off a field with "default" set, Django will use # the default. a6 = Article(pub_date=datetime(2005, 7, 31)) a6.save() self.assertEqual(a6.headline, 'Default headline') # For DateTimeFields, Django saves as much precision (in seconds) # as you give it. a7 = Article( headline='Article 7', pub_date=datetime(2005, 7, 31, 12, 30), ) a7.save() self.assertEqual(Article.objects.get(id__exact=a7.id).pub_date, datetime(2005, 7, 31, 12, 30)) a8 = Article( headline='Article 8', pub_date=datetime(2005, 7, 31, 12, 30, 45), ) a8.save() self.assertEqual(Article.objects.get(id__exact=a8.id).pub_date, datetime(2005, 7, 31, 12, 30, 45)) # Saving an object again doesn't create a new object -- it just saves # the old one. current_id = a8.id a8.save() self.assertEqual(a8.id, current_id) a8.headline = 'Updated article 8' a8.save() self.assertEqual(a8.id, current_id) # Check that != and == operators behave as expecte on instances self.assertTrue(a7 != a8) self.assertFalse(a7 == a8) self.assertEqual(a8, Article.objects.get(id__exact=a8.id)) self.assertTrue(Article.objects.get(id__exact=a8.id) != Article.objects.get(id__exact=a7.id)) self.assertFalse(Article.objects.get(id__exact=a8.id) == Article.objects.get(id__exact=a7.id)) # You can use 'in' to test for membership... self.assertTrue(a8 in Article.objects.all()) # ... but there will often be more efficient ways if that is all you need: self.assertTrue(Article.objects.filter(id=a8.id).exists()) # datetimes() returns a list of available dates of the given scope for # the given field. self.assertQuerysetEqual( Article.objects.datetimes('pub_date', 'year'), ["datetime.datetime(2005, 1, 1, 0, 0)"]) self.assertQuerysetEqual( Article.objects.datetimes('pub_date', 'month'), ["datetime.datetime(2005, 7, 1, 0, 0)"]) self.assertQuerysetEqual( Article.objects.datetimes('pub_date', 'day'), ["datetime.datetime(2005, 7, 28, 0, 0)", "datetime.datetime(2005, 7, 29, 0, 0)", "datetime.datetime(2005, 7, 30, 0, 0)", "datetime.datetime(2005, 7, 31, 0, 0)"]) self.assertQuerysetEqual( Article.objects.datetimes('pub_date', 'day', order='ASC'), ["datetime.datetime(2005, 7, 28, 0, 0)", "datetime.datetime(2005, 7, 29, 0, 0)", "datetime.datetime(2005, 7, 30, 0, 0)", "datetime.datetime(2005, 7, 31, 0, 0)"]) self.assertQuerysetEqual( Article.objects.datetimes('pub_date', 'day', order='DESC'), ["datetime.datetime(2005, 7, 31, 0, 0)", "datetime.datetime(2005, 7, 30, 0, 0)", "datetime.datetime(2005, 7, 29, 0, 0)", "datetime.datetime(2005, 7, 28, 0, 0)"]) # datetimes() requires valid arguments. self.assertRaises( TypeError, Article.objects.dates, ) six.assertRaisesRegex(self, FieldDoesNotExist, "Article has no field named 'invalid_field'", Article.objects.dates, "invalid_field", "year", ) six.assertRaisesRegex(self, AssertionError, "'kind' must be one of 'year', 'month' or 'day'.", Article.objects.dates, "pub_date", "bad_kind", ) six.assertRaisesRegex(self, AssertionError, "'order' must be either 'ASC' or 'DESC'.", Article.objects.dates, "pub_date", "year", order="bad order", ) # Use iterator() with datetimes() to return a generator that lazily # requests each result one at a time, to save memory. dates = [] for article in Article.objects.datetimes('pub_date', 'day', order='DESC').iterator(): dates.append(article) self.assertEqual(dates, [ datetime(2005, 7, 31, 0, 0), datetime(2005, 7, 30, 0, 0), datetime(2005, 7, 29, 0, 0), datetime(2005, 7, 28, 0, 0)]) # You can combine queries with & and |. s1 = Article.objects.filter(id__exact=a.id) s2 = Article.objects.filter(id__exact=a2.id) self.assertQuerysetEqual(s1 | s2, ["", ""]) self.assertQuerysetEqual(s1 & s2, []) # You can get the number of objects like this: self.assertEqual(len(Article.objects.filter(id__exact=a.id)), 1) # You can get items using index and slice notation. self.assertEqual(Article.objects.all()[0], a) self.assertQuerysetEqual(Article.objects.all()[1:3], ["", ""]) s3 = Article.objects.filter(id__exact=a3.id) self.assertQuerysetEqual((s1 | s2 | s3)[::2], ["", ""]) # Slicing works with longs (Python 2 only -- Python 3 doesn't have longs). if six.PY2: self.assertEqual(Article.objects.all()[long(0)], a) self.assertQuerysetEqual(Article.objects.all()[long(1):long(3)], ["", ""]) self.assertQuerysetEqual((s1 | s2 | s3)[::long(2)], ["", ""]) # And can be mixed with ints. self.assertQuerysetEqual(Article.objects.all()[1:long(3)], ["", ""]) # Slices (without step) are lazy: self.assertQuerysetEqual(Article.objects.all()[0:5].filter(), ["", "", "", "", ""]) # Slicing again works: self.assertQuerysetEqual(Article.objects.all()[0:5][0:2], ["", ""]) self.assertQuerysetEqual(Article.objects.all()[0:5][:2], ["", ""]) self.assertQuerysetEqual(Article.objects.all()[0:5][4:], [""]) self.assertQuerysetEqual(Article.objects.all()[0:5][5:], []) # Some more tests! self.assertQuerysetEqual(Article.objects.all()[2:][0:2], ["", ""]) self.assertQuerysetEqual(Article.objects.all()[2:][:2], ["", ""]) self.assertQuerysetEqual(Article.objects.all()[2:][2:3], [""]) # Using an offset without a limit is also possible. self.assertQuerysetEqual(Article.objects.all()[5:], ["", "", ""]) # Also, once you have sliced you can't filter, re-order or combine six.assertRaisesRegex(self, AssertionError, "Cannot filter a query once a slice has been taken.", Article.objects.all()[0:5].filter, id=a.id, ) six.assertRaisesRegex(self, AssertionError, "Cannot reorder a query once a slice has been taken.", Article.objects.all()[0:5].order_by, 'id', ) try: Article.objects.all()[0:1] & Article.objects.all()[4:5] self.fail('Should raise an AssertionError') except AssertionError as e: self.assertEqual(str(e), "Cannot combine queries once a slice has been taken.") except Exception as e: self.fail('Should raise an AssertionError, not %s' % e) # Negative slices are not supported, due to database constraints. # (hint: inverting your ordering might do what you need). try: Article.objects.all()[-1] self.fail('Should raise an AssertionError') except AssertionError as e: self.assertEqual(str(e), "Negative indexing is not supported.") except Exception as e: self.fail('Should raise an AssertionError, not %s' % e) error = None try: Article.objects.all()[0:-5] except Exception as e: error = e self.assertIsInstance(error, AssertionError) self.assertEqual(str(error), "Negative indexing is not supported.") # An Article instance doesn't have access to the "objects" attribute. # That's only available on the class. six.assertRaisesRegex(self, AttributeError, "Manager isn't accessible via Article instances", getattr, a7, "objects", ) # Bulk delete test: How many objects before and after the delete? self.assertQuerysetEqual(Article.objects.all(), ["", "", "", "", "", "", "", ""]) Article.objects.filter(id__lte=a4.id).delete() self.assertQuerysetEqual(Article.objects.all(), ["", "", "", ""]) @skipUnlessDBFeature('supports_microsecond_precision') def test_microsecond_precision(self): # In PostgreSQL, microsecond-level precision is available. a9 = Article( headline='Article 9', pub_date=datetime(2005, 7, 31, 12, 30, 45, 180), ) a9.save() self.assertEqual(Article.objects.get(pk=a9.pk).pub_date, datetime(2005, 7, 31, 12, 30, 45, 180)) @skipIfDBFeature('supports_microsecond_precision') def test_microsecond_precision_not_supported(self): # In MySQL, microsecond-level precision isn't available. You'll lose # microsecond-level precision once the data is saved. a9 = Article( headline='Article 9', pub_date=datetime(2005, 7, 31, 12, 30, 45, 180), ) a9.save() self.assertEqual(Article.objects.get(id__exact=a9.id).pub_date, datetime(2005, 7, 31, 12, 30, 45)) def test_manually_specify_primary_key(self): # You can manually specify the primary key when creating a new object. a101 = Article( id=101, headline='Article 101', pub_date=datetime(2005, 7, 31, 12, 30, 45), ) a101.save() a101 = Article.objects.get(pk=101) self.assertEqual(a101.headline, 'Article 101') def test_create_method(self): # You can create saved objects in a single step a10 = Article.objects.create( headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45), ) self.assertEqual(Article.objects.get(headline="Article 10"), a10) def test_year_lookup_edge_case(self): # Edge-case test: A year lookup should retrieve all objects in # the given year, including Jan. 1 and Dec. 31. Article.objects.create( headline='Article 11', pub_date=datetime(2008, 1, 1), ) Article.objects.create( headline='Article 12', pub_date=datetime(2008, 12, 31, 23, 59, 59, 999999), ) self.assertQuerysetEqual(Article.objects.filter(pub_date__year=2008), ["", ""]) def test_unicode_data(self): # Unicode data works, too. a = Article( headline='\u6797\u539f \u3081\u3050\u307f', pub_date=datetime(2005, 7, 28), ) a.save() self.assertEqual(Article.objects.get(pk=a.id).headline, '\u6797\u539f \u3081\u3050\u307f') def test_hash_function(self): # Model instances have a hash function, so they can be used in sets # or as dictionary keys. Two models compare as equal if their primary # keys are equal. a10 = Article.objects.create( headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45), ) a11 = Article.objects.create( headline='Article 11', pub_date=datetime(2008, 1, 1), ) a12 = Article.objects.create( headline='Article 12', pub_date=datetime(2008, 12, 31, 23, 59, 59, 999999), ) s = set([a10, a11, a12]) self.assertTrue(Article.objects.get(headline='Article 11') in s) def test_field_ordering(self): """ Field instances have a `__lt__` comparison function to define an ordering based on their creation. Prior to #17851 this ordering comparison relied on the now unsupported `__cmp__` and was assuming compared objects were both Field instances raising `AttributeError` when it should have returned `NotImplemented`. """ f1 = Field() f2 = Field(auto_created=True) f3 = Field() self.assertTrue(f2 < f1) self.assertTrue(f3 > f1) self.assertFalse(f1 == None) self.assertFalse(f2 in (None, 1, '')) def test_extra_method_select_argument_with_dashes_and_values(self): # The 'select' argument to extra() supports names with dashes in # them, as long as you use values(). Article.objects.create( headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45), ) Article.objects.create( headline='Article 11', pub_date=datetime(2008, 1, 1), ) Article.objects.create( headline='Article 12', pub_date=datetime(2008, 12, 31, 23, 59, 59, 999999), ) dicts = Article.objects.filter( pub_date__year=2008).extra( select={'dashed-value': '1'} ).values('headline', 'dashed-value') self.assertEqual([sorted(d.items()) for d in dicts], [[('dashed-value', 1), ('headline', 'Article 11')], [('dashed-value', 1), ('headline', 'Article 12')]]) def test_extra_method_select_argument_with_dashes(self): # If you use 'select' with extra() and names containing dashes on a # query that's *not* a values() query, those extra 'select' values # will silently be ignored. Article.objects.create( headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45), ) Article.objects.create( headline='Article 11', pub_date=datetime(2008, 1, 1), ) Article.objects.create( headline='Article 12', pub_date=datetime(2008, 12, 31, 23, 59, 59, 999999), ) articles = Article.objects.filter( pub_date__year=2008).extra( select={'dashed-value': '1', 'undashedvalue': '2'}) self.assertEqual(articles[0].undashedvalue, 2) def test_create_relation_with_ugettext_lazy(self): """ Test that ugettext_lazy objects work when saving model instances through various methods. Refs #10498. """ notlazy = 'test' lazy = ugettext_lazy(notlazy) Article.objects.create(headline=lazy, pub_date=datetime.now()) article = Article.objects.get() self.assertEqual(article.headline, notlazy) # test that assign + save works with Promise objecs article.headline = lazy article.save() self.assertEqual(article.headline, notlazy) # test .update() Article.objects.update(headline=lazy) article = Article.objects.get() self.assertEqual(article.headline, notlazy) # still test bulk_create() Article.objects.all().delete() Article.objects.bulk_create([Article(headline=lazy, pub_date=datetime.now())]) article = Article.objects.get() self.assertEqual(article.headline, notlazy) def test_emptyqs(self): # Can't be instantiated with self.assertRaises(TypeError): EmptyQuerySet() self.assertIsInstance(Article.objects.none(), EmptyQuerySet) def test_emptyqs_values(self): # test for #15959 Article.objects.create(headline='foo', pub_date=datetime.now()) with self.assertNumQueries(0): qs = Article.objects.none().values_list('pk') self.assertIsInstance(qs, EmptyQuerySet) self.assertIsInstance(qs, ValuesListQuerySet) self.assertEqual(len(qs), 0) def test_emptyqs_customqs(self): # A hacky test for custom QuerySet subclass - refs #17271 Article.objects.create(headline='foo', pub_date=datetime.now()) class CustomQuerySet(QuerySet): def do_something(self): return 'did something' qs = Article.objects.all() qs.__class__ = CustomQuerySet qs = qs.none() with self.assertNumQueries(0): self.assertEqual(len(qs), 0) self.assertIsInstance(qs, EmptyQuerySet) self.assertEqual(qs.do_something(), 'did something') def test_emptyqs_values_order(self): # Tests for ticket #17712 Article.objects.create(headline='foo', pub_date=datetime.now()) with self.assertNumQueries(0): self.assertEqual(len(Article.objects.none().values_list('id').order_by('id')), 0) with self.assertNumQueries(0): self.assertEqual(len(Article.objects.none().filter( id__in=Article.objects.values_list('id', flat=True))), 0) @skipUnlessDBFeature('can_distinct_on_fields') def test_emptyqs_distinct(self): # Tests for #19426 Article.objects.create(headline='foo', pub_date=datetime.now()) with self.assertNumQueries(0): self.assertEqual(len(Article.objects.none().distinct('headline', 'pub_date')), 0) def test_ticket_20278(self): sr = SelfRef.objects.create() with self.assertRaises(ObjectDoesNotExist): SelfRef.objects.get(selfref=sr) def test_eq(self): self.assertEqual(Article(id=1), Article(id=1)) self.assertNotEqual(Article(id=1), object()) self.assertNotEqual(object(), Article(id=1)) a = Article() self.assertEqual(a, a) self.assertNotEqual(Article(), a) def test_hash(self): # Value based on PK self.assertEqual(hash(Article(id=1)), hash(1)) with self.assertRaises(TypeError): # No PK value -> unhashable (because save() would then change # hash) hash(Article()) class ConcurrentSaveTests(TransactionTestCase): available_apps = ['basic'] @skipUnlessDBFeature('test_db_allows_multiple_connections') def test_concurrent_delete_with_save(self): """ Test fetching, deleting and finally saving an object - we should get an insert in this case. """ a = Article.objects.create(headline='foo', pub_date=datetime.now()) exceptions = [] def deleter(): try: # Do not delete a directly - doing so alters its state. Article.objects.filter(pk=a.pk).delete() connections[DEFAULT_DB_ALIAS].commit_unless_managed() except Exception as e: exceptions.append(e) finally: connections[DEFAULT_DB_ALIAS].close() self.assertEqual(len(exceptions), 0) t = threading.Thread(target=deleter) t.start() t.join() a.save() self.assertEqual(Article.objects.get(pk=a.pk).headline, 'foo') class ManagerTest(TestCase): QUERYSET_PROXY_METHODS = [ 'none', 'count', 'dates', 'datetimes', 'distinct', 'extra', 'get', 'get_or_create', 'update_or_create', 'create', 'bulk_create', 'filter', 'aggregate', 'annotate', 'complex_filter', 'exclude', 'in_bulk', 'iterator', 'earliest', 'latest', 'first', 'last', 'order_by', 'select_for_update', 'select_related', 'prefetch_related', 'values', 'values_list', 'update', 'reverse', 'defer', 'only', 'using', 'exists', '_insert', '_update', 'raw', ] def test_manager_methods(self): """ This test ensures that the correct set of methods from `QuerySet` are copied onto `Manager`. It's particularly useful to prevent accidentally leaking new methods into `Manager`. New `QuerySet` methods that should also be copied onto `Manager` will need to be added to `ManagerTest.QUERYSET_PROXY_METHODS`. """ self.assertEqual( sorted(BaseManager._get_queryset_methods(QuerySet).keys()), sorted(self.QUERYSET_PROXY_METHODS), ) class SelectOnSaveTests(TestCase): def test_select_on_save(self): a1 = Article.objects.create(pub_date=datetime.now()) with self.assertNumQueries(1): a1.save() asos = ArticleSelectOnSave.objects.create(pub_date=datetime.now()) with self.assertNumQueries(2): asos.save() with self.assertNumQueries(1): asos.save(force_update=True) Article.objects.all().delete() with self.assertRaises(DatabaseError): with self.assertNumQueries(1): asos.save(force_update=True) def test_select_on_save_lying_update(self): """ Test that select_on_save works correctly if the database doesn't return correct information about matched rows from UPDATE. """ # Change the manager to not return "row matched" for update(). # We are going to change the Article's _base_manager class # dynamically. This is a bit of a hack, but it seems hard to # test this properly otherwise. Article's manager, because # proxy models use their parent model's _base_manager. orig_class = Article._base_manager.__class__ class FakeQuerySet(QuerySet): # Make sure the _update method below is in fact called. called = False def _update(self, *args, **kwargs): FakeQuerySet.called = True super(FakeQuerySet, self)._update(*args, **kwargs) return 0 class FakeManager(orig_class): def get_queryset(self): return FakeQuerySet(self.model) try: Article._base_manager.__class__ = FakeManager asos = ArticleSelectOnSave.objects.create(pub_date=datetime.now()) with self.assertNumQueries(2): asos.save() self.assertTrue(FakeQuerySet.called) # This is not wanted behaviour, but this is how Django has always # behaved for databases that do not return correct information # about matched rows for UPDATE. with self.assertRaises(DatabaseError): asos.save(force_update=True) with self.assertRaises(DatabaseError): asos.save(update_fields=['pub_date']) finally: Article._base_manager.__class__ = orig_class