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django/tests/basic/tests.py
David Smith 097e3a70c1 Refs #33476 -- Applied Black's 2023 stable style.
Black 23.1.0 is released which, as the first release of the year,
introduces the 2023 stable style. This incorporates most of last year's
preview style.

https://github.com/psf/black/releases/tag/23.1.0
2023-02-01 11:04:38 +01:00

944 lines
34 KiB
Python

import inspect
import threading
from datetime import datetime, timedelta
from unittest import mock
from django.core.exceptions import MultipleObjectsReturned, ObjectDoesNotExist
from django.db import DEFAULT_DB_ALIAS, DatabaseError, connections, models
from django.db.models.manager import BaseManager
from django.db.models.query import MAX_GET_RESULTS, EmptyQuerySet
from django.test import (
SimpleTestCase,
TestCase,
TransactionTestCase,
skipUnlessDBFeature,
)
from django.utils.translation import gettext_lazy
from .models import (
Article,
ArticleSelectOnSave,
ChildPrimaryKeyWithDefault,
FeaturedArticle,
PrimaryKeyWithDefault,
SelfRef,
)
class ModelInstanceCreationTests(TestCase):
def test_object_is_not_written_to_database_until_save_was_called(self):
a = Article(
id=None,
headline="Parrot programs in Python",
pub_date=datetime(2005, 7, 28),
)
self.assertIsNone(a.id)
self.assertEqual(Article.objects.count(), 0)
# Save it into the database. You have to call save() explicitly.
a.save()
self.assertIsNotNone(a.id)
self.assertEqual(Article.objects.count(), 1)
def test_can_initialize_model_instance_using_positional_arguments(self):
"""
You can initialize a model instance using positional arguments,
which should match the field order as defined in the model.
"""
a = Article(None, "Second article", datetime(2005, 7, 29))
a.save()
self.assertEqual(a.headline, "Second article")
self.assertEqual(a.pub_date, datetime(2005, 7, 29, 0, 0))
def test_can_create_instance_using_kwargs(self):
a = Article(
id=None,
headline="Third article",
pub_date=datetime(2005, 7, 30),
)
a.save()
self.assertEqual(a.headline, "Third article")
self.assertEqual(a.pub_date, datetime(2005, 7, 30, 0, 0))
def test_autofields_generate_different_values_for_each_instance(self):
a1 = Article.objects.create(
headline="First", pub_date=datetime(2005, 7, 30, 0, 0)
)
a2 = Article.objects.create(
headline="First", pub_date=datetime(2005, 7, 30, 0, 0)
)
a3 = Article.objects.create(
headline="First", pub_date=datetime(2005, 7, 30, 0, 0)
)
self.assertNotEqual(a3.id, a1.id)
self.assertNotEqual(a3.id, a2.id)
def test_can_mix_and_match_position_and_kwargs(self):
# You can also mix and match position and keyword arguments, but
# be sure not to duplicate field information.
a = Article(None, "Fourth article", pub_date=datetime(2005, 7, 31))
a.save()
self.assertEqual(a.headline, "Fourth article")
def test_positional_and_keyword_args_for_the_same_field(self):
msg = "Article() got both positional and keyword arguments for field '%s'."
with self.assertRaisesMessage(TypeError, msg % "headline"):
Article(None, "Fifth article", headline="Other headline.")
with self.assertRaisesMessage(TypeError, msg % "headline"):
Article(None, "Sixth article", headline="")
with self.assertRaisesMessage(TypeError, msg % "pub_date"):
Article(None, "Seventh article", datetime(2021, 3, 1), pub_date=None)
def test_cannot_create_instance_with_invalid_kwargs(self):
msg = "Article() got unexpected keyword arguments: 'foo'"
with self.assertRaisesMessage(TypeError, msg):
Article(
id=None,
headline="Some headline",
pub_date=datetime(2005, 7, 31),
foo="bar",
)
msg = "Article() got unexpected keyword arguments: 'foo', 'bar'"
with self.assertRaisesMessage(TypeError, msg):
Article(
id=None,
headline="Some headline",
pub_date=datetime(2005, 7, 31),
foo="bar",
bar="baz",
)
def test_can_leave_off_value_for_autofield_and_it_gets_value_on_save(self):
"""
You can leave off the value for an AutoField when creating an
object, because it'll get filled in automatically when you save().
"""
a = Article(headline="Article 5", pub_date=datetime(2005, 7, 31))
a.save()
self.assertEqual(a.headline, "Article 5")
self.assertIsNotNone(a.id)
def test_leaving_off_a_field_with_default_set_the_default_will_be_saved(self):
a = Article(pub_date=datetime(2005, 7, 31))
a.save()
self.assertEqual(a.headline, "Default headline")
def test_for_datetimefields_saves_as_much_precision_as_was_given(self):
"""as much precision in *seconds*"""
a1 = Article(
headline="Article 7",
pub_date=datetime(2005, 7, 31, 12, 30),
)
a1.save()
self.assertEqual(
Article.objects.get(id__exact=a1.id).pub_date, datetime(2005, 7, 31, 12, 30)
)
a2 = Article(
headline="Article 8",
pub_date=datetime(2005, 7, 31, 12, 30, 45),
)
a2.save()
self.assertEqual(
Article.objects.get(id__exact=a2.id).pub_date,
datetime(2005, 7, 31, 12, 30, 45),
)
def test_saving_an_object_again_does_not_create_a_new_object(self):
a = Article(headline="original", pub_date=datetime(2014, 5, 16))
a.save()
current_id = a.id
a.save()
self.assertEqual(a.id, current_id)
a.headline = "Updated headline"
a.save()
self.assertEqual(a.id, current_id)
def test_querysets_checking_for_membership(self):
headlines = ["Parrot programs in Python", "Second article", "Third article"]
some_pub_date = datetime(2014, 5, 16, 12, 1)
for headline in headlines:
Article(headline=headline, pub_date=some_pub_date).save()
a = Article(headline="Some headline", pub_date=some_pub_date)
a.save()
# You can use 'in' to test for membership...
self.assertIn(a, Article.objects.all())
# ... but there will often be more efficient ways if that is all you need:
self.assertTrue(Article.objects.filter(id=a.id).exists())
def test_save_primary_with_default(self):
# An UPDATE attempt is skipped when a primary key has default.
with self.assertNumQueries(1):
PrimaryKeyWithDefault().save()
def test_save_parent_primary_with_default(self):
# An UPDATE attempt is skipped when an inherited primary key has
# default.
with self.assertNumQueries(2):
ChildPrimaryKeyWithDefault().save()
class ModelTest(TestCase):
def test_objects_attribute_is_only_available_on_the_class_itself(self):
with self.assertRaisesMessage(
AttributeError, "Manager isn't accessible via Article instances"
):
getattr(
Article(),
"objects",
)
self.assertFalse(hasattr(Article(), "objects"))
self.assertTrue(hasattr(Article, "objects"))
def test_queryset_delete_removes_all_items_in_that_queryset(self):
headlines = ["An article", "Article One", "Amazing article", "Boring article"]
some_pub_date = datetime(2014, 5, 16, 12, 1)
for headline in headlines:
Article(headline=headline, pub_date=some_pub_date).save()
self.assertQuerySetEqual(
Article.objects.order_by("headline"),
sorted(headlines),
transform=lambda a: a.headline,
)
Article.objects.filter(headline__startswith="A").delete()
self.assertEqual(Article.objects.get().headline, "Boring article")
def test_not_equal_and_equal_operators_behave_as_expected_on_instances(self):
some_pub_date = datetime(2014, 5, 16, 12, 1)
a1 = Article.objects.create(headline="First", pub_date=some_pub_date)
a2 = Article.objects.create(headline="Second", pub_date=some_pub_date)
self.assertNotEqual(a1, a2)
self.assertEqual(a1, Article.objects.get(id__exact=a1.id))
self.assertNotEqual(
Article.objects.get(id__exact=a1.id), Article.objects.get(id__exact=a2.id)
)
def test_microsecond_precision(self):
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),
)
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.
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),
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__year=2008),
[a11, a12],
)
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 = {a10, a11, a12}
self.assertIn(Article.objects.get(headline="Article 11"), s)
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.bulk_create(
[
Article(
headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45)
),
Article(headline="Article 11", pub_date=datetime(2008, 1, 1)),
Article(
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.bulk_create(
[
Article(
headline="Article 10", pub_date=datetime(2005, 7, 31, 12, 30, 45)
),
Article(headline="Article 11", pub_date=datetime(2008, 1, 1)),
Article(
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_gettext_lazy(self):
"""
gettext_lazy objects work when saving model instances
through various methods. Refs #10498.
"""
notlazy = "test"
lazy = gettext_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 objects
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):
msg = "EmptyQuerySet can't be instantiated"
with self.assertRaisesMessage(TypeError, msg):
EmptyQuerySet()
self.assertIsInstance(Article.objects.none(), EmptyQuerySet)
self.assertNotIsInstance("", 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.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(models.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.assertEqual(a, mock.ANY)
self.assertNotEqual(Article(), a)
def test_hash(self):
# Value based on PK
self.assertEqual(hash(Article(id=1)), hash(1))
msg = "Model instances without primary key value are unhashable"
with self.assertRaisesMessage(TypeError, msg):
# No PK value -> unhashable (because save() would then change
# hash)
hash(Article())
def test_missing_hash_not_inherited(self):
class NoHash(models.Model):
def __eq__(self, other):
return super.__eq__(other)
with self.assertRaisesMessage(TypeError, "unhashable type: 'NoHash'"):
hash(NoHash(id=1))
def test_specified_parent_hash_inherited(self):
class ParentHash(models.Model):
def __eq__(self, other):
return super.__eq__(other)
__hash__ = models.Model.__hash__
self.assertEqual(hash(ParentHash(id=1)), 1)
def test_delete_and_access_field(self):
# Accessing a field after it's deleted from a model reloads its value.
pub_date = datetime.now()
article = Article.objects.create(headline="foo", pub_date=pub_date)
new_pub_date = article.pub_date + timedelta(days=10)
article.headline = "bar"
article.pub_date = new_pub_date
del article.headline
with self.assertNumQueries(1):
self.assertEqual(article.headline, "foo")
# Fields that weren't deleted aren't reloaded.
self.assertEqual(article.pub_date, new_pub_date)
def test_multiple_objects_max_num_fetched(self):
max_results = MAX_GET_RESULTS - 1
Article.objects.bulk_create(
Article(headline="Area %s" % i, pub_date=datetime(2005, 7, 28))
for i in range(max_results)
)
self.assertRaisesMessage(
MultipleObjectsReturned,
"get() returned more than one Article -- it returned %d!" % max_results,
Article.objects.get,
headline__startswith="Area",
)
Article.objects.create(
headline="Area %s" % max_results, pub_date=datetime(2005, 7, 28)
)
self.assertRaisesMessage(
MultipleObjectsReturned,
"get() returned more than one Article -- it returned more than %d!"
% max_results,
Article.objects.get,
headline__startswith="Area",
)
class ModelLookupTest(TestCase):
@classmethod
def setUpTestData(cls):
# Create an Article.
cls.a = Article(
id=None,
headline="Swallow programs in Python",
pub_date=datetime(2005, 7, 28),
)
# Save it into the database. You have to call save() explicitly.
cls.a.save()
def test_all_lookup(self):
# Change values by changing the attributes, then calling save().
self.a.headline = "Parrot programs in Python"
self.a.save()
# Article.objects.all() returns all the articles in the database.
self.assertSequenceEqual(Article.objects.all(), [self.a])
def test_rich_lookup(self):
# Django provides a rich database lookup API.
self.assertEqual(Article.objects.get(id__exact=self.a.id), self.a)
self.assertEqual(Article.objects.get(headline__startswith="Swallow"), self.a)
self.assertEqual(Article.objects.get(pub_date__year=2005), self.a)
self.assertEqual(
Article.objects.get(pub_date__year=2005, pub_date__month=7), self.a
)
self.assertEqual(
Article.objects.get(
pub_date__year=2005, pub_date__month=7, pub_date__day=28
),
self.a,
)
self.assertEqual(Article.objects.get(pub_date__week_day=5), self.a)
def test_equal_lookup(self):
# The "__exact" lookup type can be omitted, as a shortcut.
self.assertEqual(Article.objects.get(id=self.a.id), self.a)
self.assertEqual(
Article.objects.get(headline="Swallow programs in Python"), self.a
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__year=2005),
[self.a],
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__year=2004),
[],
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__year=2005, pub_date__month=7),
[self.a],
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__week_day=5),
[self.a],
)
self.assertSequenceEqual(
Article.objects.filter(pub_date__week_day=6),
[],
)
def test_does_not_exist(self):
# Django raises an Article.DoesNotExist exception for get() if the
# parameters don't match any object.
with self.assertRaisesMessage(
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.
with self.assertRaises(ObjectDoesNotExist):
Article.objects.get(pub_date__year=2005, pub_date__month=8)
with self.assertRaisesMessage(
ObjectDoesNotExist, "Article matching query does not exist."
):
Article.objects.get(
pub_date__week_day=6,
)
def test_lookup_by_primary_key(self):
# 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=self.a.id), self.a)
# pk can be used as a shortcut for the primary key name in any query.
self.assertSequenceEqual(Article.objects.filter(pk__in=[self.a.id]), [self.a])
# Model instances of the same type and same ID are considered equal.
a = Article.objects.get(pk=self.a.id)
b = Article.objects.get(pk=self.a.id)
self.assertEqual(a, b)
def test_too_many(self):
# Create a very similar object
a = Article(
id=None,
headline="Swallow bites 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
msg = "get() returned more than one Article -- it returned 2!"
with self.assertRaisesMessage(MultipleObjectsReturned, msg):
Article.objects.get(
headline__startswith="Swallow",
)
with self.assertRaisesMessage(MultipleObjectsReturned, msg):
Article.objects.get(
pub_date__year=2005,
)
with self.assertRaisesMessage(MultipleObjectsReturned, msg):
Article.objects.get(pub_date__year=2005, pub_date__month=7)
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()
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(SimpleTestCase):
QUERYSET_PROXY_METHODS = [
"none",
"count",
"dates",
"datetimes",
"distinct",
"extra",
"get",
"get_or_create",
"update_or_create",
"create",
"bulk_create",
"bulk_update",
"filter",
"aggregate",
"annotate",
"alias",
"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",
"contains",
"explain",
"_insert",
"_update",
"raw",
"union",
"intersection",
"difference",
"aaggregate",
"abulk_create",
"abulk_update",
"acontains",
"acount",
"acreate",
"aearliest",
"aexists",
"aexplain",
"afirst",
"aget",
"aget_or_create",
"ain_bulk",
"aiterator",
"alast",
"alatest",
"aupdate",
"aupdate_or_create",
]
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(models.QuerySet)),
sorted(self.QUERYSET_PROXY_METHODS),
)
def test_manager_method_attributes(self):
self.assertEqual(Article.objects.get.__doc__, models.QuerySet.get.__doc__)
self.assertEqual(Article.objects.count.__name__, models.QuerySet.count.__name__)
def test_manager_method_signature(self):
self.assertEqual(
str(inspect.signature(Article.objects.bulk_create)),
"(objs, batch_size=None, ignore_conflicts=False, update_conflicts=False, "
"update_fields=None, unique_fields=None)",
)
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.assertRaisesMessage(
DatabaseError, "Forced update did not affect any rows."
):
with self.assertNumQueries(1):
asos.save(force_update=True)
def test_select_on_save_lying_update(self):
"""
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._queryset_class
class FakeQuerySet(models.QuerySet):
# Make sure the _update method below is in fact called.
called = False
def _update(self, *args, **kwargs):
FakeQuerySet.called = True
super()._update(*args, **kwargs)
return 0
try:
Article._base_manager._queryset_class = FakeQuerySet
asos = ArticleSelectOnSave.objects.create(pub_date=datetime.now())
with self.assertNumQueries(3):
asos.save()
self.assertTrue(FakeQuerySet.called)
# This is not wanted behavior, but this is how Django has always
# behaved for databases that do not return correct information
# about matched rows for UPDATE.
with self.assertRaisesMessage(
DatabaseError, "Forced update did not affect any rows."
):
asos.save(force_update=True)
msg = (
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block."
)
with self.assertRaisesMessage(DatabaseError, msg) as cm:
asos.save(update_fields=["pub_date"])
self.assertIsInstance(cm.exception.__cause__, DatabaseError)
finally:
Article._base_manager._queryset_class = orig_class
class ModelRefreshTests(TestCase):
def test_refresh(self):
a = Article.objects.create(pub_date=datetime.now())
Article.objects.create(pub_date=datetime.now())
Article.objects.filter(pk=a.pk).update(headline="new headline")
with self.assertNumQueries(1):
a.refresh_from_db()
self.assertEqual(a.headline, "new headline")
orig_pub_date = a.pub_date
new_pub_date = a.pub_date + timedelta(10)
Article.objects.update(headline="new headline 2", pub_date=new_pub_date)
with self.assertNumQueries(1):
a.refresh_from_db(fields=["headline"])
self.assertEqual(a.headline, "new headline 2")
self.assertEqual(a.pub_date, orig_pub_date)
with self.assertNumQueries(1):
a.refresh_from_db()
self.assertEqual(a.pub_date, new_pub_date)
def test_unknown_kwarg(self):
s = SelfRef.objects.create()
msg = "refresh_from_db() got an unexpected keyword argument 'unknown_kwarg'"
with self.assertRaisesMessage(TypeError, msg):
s.refresh_from_db(unknown_kwarg=10)
def test_lookup_in_fields(self):
s = SelfRef.objects.create()
msg = (
'Found "__" in fields argument. Relations and transforms are not allowed '
"in fields."
)
with self.assertRaisesMessage(ValueError, msg):
s.refresh_from_db(fields=["foo__bar"])
def test_refresh_fk(self):
s1 = SelfRef.objects.create()
s2 = SelfRef.objects.create()
s3 = SelfRef.objects.create(selfref=s1)
s3_copy = SelfRef.objects.get(pk=s3.pk)
s3_copy.selfref.touched = True
s3.selfref = s2
s3.save()
with self.assertNumQueries(1):
s3_copy.refresh_from_db()
with self.assertNumQueries(1):
# The old related instance was thrown away (the selfref_id has
# changed). It needs to be reloaded on access, so one query
# executed.
self.assertFalse(hasattr(s3_copy.selfref, "touched"))
self.assertEqual(s3_copy.selfref, s2)
def test_refresh_null_fk(self):
s1 = SelfRef.objects.create()
s2 = SelfRef.objects.create(selfref=s1)
s2.selfref = None
s2.refresh_from_db()
self.assertEqual(s2.selfref, s1)
def test_refresh_unsaved(self):
pub_date = datetime.now()
a = Article.objects.create(pub_date=pub_date)
a2 = Article(id=a.pk)
with self.assertNumQueries(1):
a2.refresh_from_db()
self.assertEqual(a2.pub_date, pub_date)
self.assertEqual(a2._state.db, "default")
def test_refresh_fk_on_delete_set_null(self):
a = Article.objects.create(
headline="Parrot programs in Python",
pub_date=datetime(2005, 7, 28),
)
s1 = SelfRef.objects.create(article=a)
a.delete()
s1.refresh_from_db()
self.assertIsNone(s1.article_id)
self.assertIsNone(s1.article)
def test_refresh_no_fields(self):
a = Article.objects.create(pub_date=datetime.now())
with self.assertNumQueries(0):
a.refresh_from_db(fields=[])
def test_refresh_clears_reverse_related(self):
"""refresh_from_db() clear cached reverse relations."""
article = Article.objects.create(
headline="Parrot programs in Python",
pub_date=datetime(2005, 7, 28),
)
self.assertFalse(hasattr(article, "featured"))
FeaturedArticle.objects.create(article_id=article.pk)
article.refresh_from_db()
self.assertTrue(hasattr(article, "featured"))
def test_refresh_clears_one_to_one_field(self):
article = Article.objects.create(
headline="Parrot programs in Python",
pub_date=datetime(2005, 7, 28),
)
featured = FeaturedArticle.objects.create(article_id=article.pk)
self.assertEqual(featured.article.headline, "Parrot programs in Python")
article.headline = "Parrot programs in Python 2.0"
article.save()
featured.refresh_from_db()
self.assertEqual(featured.article.headline, "Parrot programs in Python 2.0")
def test_prefetched_cache_cleared(self):
a = Article.objects.create(pub_date=datetime(2005, 7, 28))
s = SelfRef.objects.create(article=a)
# refresh_from_db() without fields=[...]
a1_prefetched = Article.objects.prefetch_related("selfref_set").first()
self.assertCountEqual(a1_prefetched.selfref_set.all(), [s])
s.article = None
s.save()
# Relation is cleared and prefetch cache is stale.
self.assertCountEqual(a1_prefetched.selfref_set.all(), [s])
a1_prefetched.refresh_from_db()
# Cache was cleared and new results are available.
self.assertCountEqual(a1_prefetched.selfref_set.all(), [])
# refresh_from_db() with fields=[...]
a2_prefetched = Article.objects.prefetch_related("selfref_set").first()
self.assertCountEqual(a2_prefetched.selfref_set.all(), [])
s.article = a
s.save()
# Relation is added and prefetch cache is stale.
self.assertCountEqual(a2_prefetched.selfref_set.all(), [])
a2_prefetched.refresh_from_db(fields=["selfref_set"])
# Cache was cleared and new results are available.
self.assertCountEqual(a2_prefetched.selfref_set.all(), [s])