from copy import deepcopy
import datetime
from django.core.exceptions import MultipleObjectsReturned, FieldError
from django.db import models, transaction
from django.test import TestCase
from django.utils import six
from django.utils.translation import ugettext_lazy
from .models import (Article, Reporter, First, Third, Parent, Child,
ToFieldChild, Category, Record, Relation, School, Student)
class ManyToOneTests(TestCase):
def setUp(self):
# Create a few Reporters.
self.r = Reporter(first_name='John', last_name='Smith', email='john@example.com')
self.r.save()
self.r2 = Reporter(first_name='Paul', last_name='Jones', email='paul@example.com')
self.r2.save()
# Create an Article.
self.a = Article(id=None, headline="This is a test",
pub_date=datetime.date(2005, 7, 27), reporter=self.r)
self.a.save()
def test_get(self):
# Article objects have access to their related Reporter objects.
r = self.a.reporter
self.assertEqual(r.id, self.r.id)
# These are strings instead of unicode strings because that's what was used in
# the creation of this reporter (and we haven't refreshed the data from the
# database, which always returns unicode strings).
self.assertEqual((r.first_name, self.r.last_name), ('John', 'Smith'))
def test_create(self):
# You can also instantiate an Article by passing the Reporter's ID
# instead of a Reporter object.
a3 = Article(id=None, headline="Third article",
pub_date=datetime.date(2005, 7, 27), reporter_id=self.r.id)
a3.save()
self.assertEqual(a3.reporter.id, self.r.id)
# Similarly, the reporter ID can be a string.
a4 = Article(id=None, headline="Fourth article",
pub_date=datetime.date(2005, 7, 27), reporter_id=str(self.r.id))
a4.save()
self.assertEqual(repr(a4.reporter), "<Reporter: John Smith>")
def test_add(self):
# Create an Article via the Reporter object.
new_article = self.r.article_set.create(headline="John's second story",
pub_date=datetime.date(2005, 7, 29))
self.assertEqual(repr(new_article), "<Article: John's second story>")
self.assertEqual(new_article.reporter.id, self.r.id)
# Create a new article, and add it to the article set.
new_article2 = Article(headline="Paul's story", pub_date=datetime.date(2006, 1, 17))
self.r.article_set.add(new_article2)
self.assertEqual(new_article2.reporter.id, self.r.id)
self.assertQuerysetEqual(self.r.article_set.all(),
[
"<Article: John's second story>",
"<Article: Paul's story>",
"<Article: This is a test>",
])
# Add the same article to a different article set - check that it moves.
self.r2.article_set.add(new_article2)
self.assertEqual(new_article2.reporter.id, self.r2.id)
self.assertQuerysetEqual(self.r2.article_set.all(), ["<Article: Paul's story>"])
# Adding an object of the wrong type raises TypeError.
with transaction.atomic():
with six.assertRaisesRegex(self, TypeError,
"'Article' instance expected, got <Reporter.*"):
self.r.article_set.add(self.r2)
self.assertQuerysetEqual(self.r.article_set.all(),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
def test_assign(self):
new_article = self.r.article_set.create(headline="John's second story",
pub_date=datetime.date(2005, 7, 29))
new_article2 = self.r2.article_set.create(headline="Paul's story",
pub_date=datetime.date(2006, 1, 17))
# Assign the article to the reporter directly using the descriptor.
new_article2.reporter = self.r
new_article2.save()
self.assertEqual(repr(new_article2.reporter), "<Reporter: John Smith>")
self.assertEqual(new_article2.reporter.id, self.r.id)
self.assertQuerysetEqual(self.r.article_set.all(), [
"<Article: John's second story>",
"<Article: Paul's story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(self.r2.article_set.all(), [])
# Set the article back again using set descriptor.
self.r2.article_set = [new_article, new_article2]
self.assertQuerysetEqual(self.r.article_set.all(), ["<Article: This is a test>"])
self.assertQuerysetEqual(self.r2.article_set.all(),
[
"<Article: John's second story>",
"<Article: Paul's story>",
])
# Funny case - assignment notation can only go so far; because the
# ForeignKey cannot be null, existing members of the set must remain.
self.r.article_set = [new_article]
self.assertQuerysetEqual(self.r.article_set.all(),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(self.r2.article_set.all(), ["<Article: Paul's story>"])
# Reporter cannot be null - there should not be a clear or remove method
self.assertFalse(hasattr(self.r2.article_set, 'remove'))
self.assertFalse(hasattr(self.r2.article_set, 'clear'))
def test_selects(self):
self.r.article_set.create(headline="John's second story",
pub_date=datetime.date(2005, 7, 29))
self.r2.article_set.create(headline="Paul's story",
pub_date=datetime.date(2006, 1, 17))
# Reporter objects have access to their related Article objects.
self.assertQuerysetEqual(self.r.article_set.all(), [
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(self.r.article_set.filter(headline__startswith='This'),
["<Article: This is a test>"])
self.assertEqual(self.r.article_set.count(), 2)
self.assertEqual(self.r2.article_set.count(), 1)
# Get articles by id
self.assertQuerysetEqual(Article.objects.filter(id__exact=self.a.id),
["<Article: This is a test>"])
self.assertQuerysetEqual(Article.objects.filter(pk=self.a.id),
["<Article: This is a test>"])
# Query on an article property
self.assertQuerysetEqual(Article.objects.filter(headline__startswith='This'),
["<Article: This is a test>"])
# The API automatically follows relationships as far as you need.
# Use double underscores to separate relationships.
# This works as many levels deep as you want. There's no limit.
# Find all Articles for any Reporter whose first name is "John".
self.assertQuerysetEqual(Article.objects.filter(reporter__first_name__exact='John'),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
# Check that implied __exact also works
self.assertQuerysetEqual(Article.objects.filter(reporter__first_name='John'),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
# Query twice over the related field.
self.assertQuerysetEqual(
Article.objects.filter(reporter__first_name__exact='John',
reporter__last_name__exact='Smith'),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
# The underlying query only makes one join when a related table is referenced twice.
queryset = Article.objects.filter(reporter__first_name__exact='John',
reporter__last_name__exact='Smith')
self.assertNumQueries(1, list, queryset)
self.assertEqual(queryset.query.get_compiler(queryset.db).as_sql()[0].count('INNER JOIN'), 1)
# The automatically joined table has a predictable name.
self.assertQuerysetEqual(
Article.objects.filter(reporter__first_name__exact='John').extra(
where=["many_to_one_reporter.last_name='Smith'"]),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
# ... and should work fine with the unicode that comes out of forms.Form.cleaned_data
self.assertQuerysetEqual(
(Article.objects
.filter(reporter__first_name__exact='John')
.extra(where=["many_to_one_reporter.last_name='%s'" % 'Smith'])),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
# Find all Articles for a Reporter.
# Use direct ID check, pk check, and object comparison
self.assertQuerysetEqual(
Article.objects.filter(reporter__id__exact=self.r.id),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(
Article.objects.filter(reporter__pk=self.r.id),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(
Article.objects.filter(reporter=self.r.id),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(
Article.objects.filter(reporter=self.r),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(
Article.objects.filter(reporter__in=[self.r.id, self.r2.id]).distinct(),
[
"<Article: John's second story>",
"<Article: Paul's story>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(
Article.objects.filter(reporter__in=[self.r, self.r2]).distinct(),
[
"<Article: John's second story>",
"<Article: Paul's story>",
"<Article: This is a test>",
])
# You can also use a queryset instead of a literal list of instances.
# The queryset must be reduced to a list of values using values(),
# then converted into a query
self.assertQuerysetEqual(
Article.objects.filter(
reporter__in=Reporter.objects.filter(first_name='John').values('pk').query
).distinct(),
[
"<Article: John's second story>",
"<Article: This is a test>",
])
def test_reverse_selects(self):
a3 = Article.objects.create(id=None, headline="Third article",
pub_date=datetime.date(2005, 7, 27), reporter_id=self.r.id)
Article.objects.create(id=None, headline="Fourth article",
pub_date=datetime.date(2005, 7, 27), reporter_id=str(self.r.id))
# Reporters can be queried
self.assertQuerysetEqual(Reporter.objects.filter(id__exact=self.r.id),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(Reporter.objects.filter(pk=self.r.id),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(Reporter.objects.filter(first_name__startswith='John'),
["<Reporter: John Smith>"])
# Reporters can query in opposite direction of ForeignKey definition
self.assertQuerysetEqual(Reporter.objects.filter(article__id__exact=self.a.id),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(Reporter.objects.filter(article__pk=self.a.id),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(Reporter.objects.filter(article=self.a.id),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(Reporter.objects.filter(article=self.a),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(
Reporter.objects.filter(article__in=[self.a.id, a3.id]).distinct(),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(
Reporter.objects.filter(article__in=[self.a.id, a3]).distinct(),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(
Reporter.objects.filter(article__in=[self.a, a3]).distinct(),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(
Reporter.objects.filter(article__headline__startswith='T'),
["<Reporter: John Smith>", "<Reporter: John Smith>"],
ordered=False
)
self.assertQuerysetEqual(
Reporter.objects.filter(article__headline__startswith='T').distinct(),
["<Reporter: John Smith>"])
# Counting in the opposite direction works in conjunction with distinct()
self.assertEqual(
Reporter.objects.filter(article__headline__startswith='T').count(), 2)
self.assertEqual(
Reporter.objects.filter(article__headline__startswith='T').distinct().count(), 1)
# Queries can go round in circles.
self.assertQuerysetEqual(
Reporter.objects.filter(article__reporter__first_name__startswith='John'),
[
"<Reporter: John Smith>",
"<Reporter: John Smith>",
"<Reporter: John Smith>",
],
ordered=False
)
self.assertQuerysetEqual(
Reporter.objects.filter(article__reporter__first_name__startswith='John').distinct(),
["<Reporter: John Smith>"])
self.assertQuerysetEqual(
Reporter.objects.filter(article__reporter__exact=self.r).distinct(),
["<Reporter: John Smith>"])
# Check that implied __exact also works.
self.assertQuerysetEqual(
Reporter.objects.filter(article__reporter=self.r).distinct(),
["<Reporter: John Smith>"])
# It's possible to use values() calls across many-to-one relations.
# (Note, too, that we clear the ordering here so as not to drag the
# 'headline' field into the columns being used to determine uniqueness)
d = {'reporter__first_name': 'John', 'reporter__last_name': 'Smith'}
self.assertEqual([d],
list(Article.objects.filter(reporter=self.r).distinct().order_by()
.values('reporter__first_name', 'reporter__last_name')))
def test_select_related(self):
# Check that Article.objects.select_related().dates() works properly when
# there are multiple Articles with the same date but different foreign-key
# objects (Reporters).
r1 = Reporter.objects.create(first_name='Mike', last_name='Royko', email='royko@suntimes.com')
r2 = Reporter.objects.create(first_name='John', last_name='Kass', email='jkass@tribune.com')
Article.objects.create(headline='First', pub_date=datetime.date(1980, 4, 23), reporter=r1)
Article.objects.create(headline='Second', pub_date=datetime.date(1980, 4, 23), reporter=r2)
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'day')),
[
datetime.date(1980, 4, 23),
datetime.date(2005, 7, 27),
])
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'month')),
[
datetime.date(1980, 4, 1),
datetime.date(2005, 7, 1),
])
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'year')),
[
datetime.date(1980, 1, 1),
datetime.date(2005, 1, 1),
])
def test_delete(self):
self.r.article_set.create(headline="John's second story",
pub_date=datetime.date(2005, 7, 29))
self.r2.article_set.create(headline="Paul's story",
pub_date=datetime.date(2006, 1, 17))
Article.objects.create(id=None, headline="Third article",
pub_date=datetime.date(2005, 7, 27), reporter_id=self.r.id)
Article.objects.create(id=None, headline="Fourth article",
pub_date=datetime.date(2005, 7, 27), reporter_id=str(self.r.id))
# If you delete a reporter, his articles will be deleted.
self.assertQuerysetEqual(Article.objects.all(),
[
"<Article: Fourth article>",
"<Article: John's second story>",
"<Article: Paul's story>",
"<Article: Third article>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(Reporter.objects.order_by('first_name'),
[
"<Reporter: John Smith>",
"<Reporter: Paul Jones>",
])
self.r2.delete()
self.assertQuerysetEqual(Article.objects.all(),
[
"<Article: Fourth article>",
"<Article: John's second story>",
"<Article: Third article>",
"<Article: This is a test>",
])
self.assertQuerysetEqual(Reporter.objects.order_by('first_name'),
["<Reporter: John Smith>"])
# You can delete using a JOIN in the query.
Reporter.objects.filter(article__headline__startswith='This').delete()
self.assertQuerysetEqual(Reporter.objects.all(), [])
self.assertQuerysetEqual(Article.objects.all(), [])
def test_explicit_fk(self):
# Create a new Article with get_or_create using an explicit value
# for a ForeignKey.
a2, created = Article.objects.get_or_create(id=None,
headline="John's second test",
pub_date=datetime.date(2011, 5, 7),
reporter_id=self.r.id)
self.assertTrue(created)
self.assertEqual(a2.reporter.id, self.r.id)
# You can specify filters containing the explicit FK value.
self.assertQuerysetEqual(
Article.objects.filter(reporter_id__exact=self.r.id),
[
"<Article: John's second test>",
"<Article: This is a test>",
])
# Create an Article by Paul for the same date.
a3 = Article.objects.create(id=None, headline="Paul's commentary",
pub_date=datetime.date(2011, 5, 7),
reporter_id=self.r2.id)
self.assertEqual(a3.reporter.id, self.r2.id)
# Get should respect explicit foreign keys as well.
self.assertRaises(MultipleObjectsReturned,
Article.objects.get, reporter_id=self.r.id)
self.assertEqual(repr(a3),
repr(Article.objects.get(reporter_id=self.r2.id,
pub_date=datetime.date(2011, 5, 7))))
def test_deepcopy_and_circular_references(self):
# Regression for #12876 -- Model methods that include queries that
# recursive don't cause recursion depth problems under deepcopy.
self.r.cached_query = Article.objects.filter(reporter=self.r)
self.assertEqual(repr(deepcopy(self.r)), "<Reporter: John Smith>")
def test_manager_class_caching(self):
r1 = Reporter.objects.create(first_name='Mike')
r2 = Reporter.objects.create(first_name='John')
# Same twice
self.assertIs(r1.article_set.__class__, r1.article_set.__class__)
# Same as each other
self.assertIs(r1.article_set.__class__, r2.article_set.__class__)
def test_create_relation_with_ugettext_lazy(self):
reporter = Reporter.objects.create(first_name='John',
last_name='Smith',
email='john.smith@example.com')
lazy = ugettext_lazy('test')
reporter.article_set.create(headline=lazy,
pub_date=datetime.date(2011, 6, 10))
notlazy = six.text_type(lazy)
article = reporter.article_set.get()
self.assertEqual(article.headline, notlazy)
def test_values_list_exception(self):
expected_message = "Cannot resolve keyword 'notafield' into field. Choices are: %s"
self.assertRaisesMessage(FieldError,
expected_message % ', '.join(sorted(f.name for f in Reporter._meta.get_fields())),
Article.objects.values_list,
'reporter__notafield')
self.assertRaisesMessage(FieldError,
expected_message % ', '.join(['EXTRA'] + sorted(f.name for f in Article._meta.get_fields())),
Article.objects.extra(select={'EXTRA': 'EXTRA_SELECT'}).values_list,
'notafield')
def test_fk_assignment_and_related_object_cache(self):
# Tests of ForeignKey assignment and the related-object cache (see #6886).
p = Parent.objects.create(name="Parent")
c = Child.objects.create(name="Child", parent=p)
# Look up the object again so that we get a "fresh" object.
c = Child.objects.get(name="Child")
p = c.parent
# Accessing the related object again returns the exactly same object.
self.assertIs(c.parent, p)
# But if we kill the cache, we get a new object.
del c._parent_cache
self.assertIsNot(c.parent, p)
# Assigning a new object results in that object getting cached immediately.
p2 = Parent.objects.create(name="Parent 2")
c.parent = p2
self.assertIs(c.parent, p2)
# Assigning None succeeds if field is null=True.
p.bestchild = None
self.assertIsNone(p.bestchild)
# bestchild should still be None after saving.
p.save()
self.assertIsNone(p.bestchild)
# bestchild should still be None after fetching the object again.
p = Parent.objects.get(name="Parent")
self.assertIsNone(p.bestchild)
# Assigning None fails: Child.parent is null=False.
self.assertRaises(ValueError, setattr, c, "parent", None)
# You also can't assign an object of the wrong type here
self.assertRaises(ValueError, setattr, c, "parent", First(id=1, second=1))
# Nor can you explicitly assign None to Child.parent during object
# creation (regression for #9649).
self.assertRaises(ValueError, Child, name='xyzzy', parent=None)
self.assertRaises(ValueError, Child.objects.create, name='xyzzy', parent=None)
# Creation using keyword argument should cache the related object.
p = Parent.objects.get(name="Parent")
c = Child(parent=p)
self.assertIs(c.parent, p)
# Creation using keyword argument and unsaved related instance (#8070).
p = Parent()
with self.assertRaisesMessage(ValueError,
'Cannot assign "%r": "%s" instance isn\'t saved in the database.'
% (p, Child.parent.field.rel.to._meta.object_name)):
Child(parent=p)
with self.assertRaisesMessage(ValueError,
'Cannot assign "%r": "%s" instance isn\'t saved in the database.'
% (p, Child.parent.field.rel.to._meta.object_name)):
ToFieldChild(parent=p)
# Creation using attname keyword argument and an id will cause the
# related object to be fetched.
p = Parent.objects.get(name="Parent")
c = Child(parent_id=p.id)
self.assertIsNot(c.parent, p)
self.assertEqual(c.parent, p)
def test_multiple_foreignkeys(self):
# Test of multiple ForeignKeys to the same model (bug #7125).
c1 = Category.objects.create(name='First')
c2 = Category.objects.create(name='Second')
c3 = Category.objects.create(name='Third')
r1 = Record.objects.create(category=c1)
r2 = Record.objects.create(category=c1)
r3 = Record.objects.create(category=c2)
r4 = Record.objects.create(category=c2)
r5 = Record.objects.create(category=c3)
Relation.objects.create(left=r1, right=r2)
Relation.objects.create(left=r3, right=r4)
Relation.objects.create(left=r1, right=r3)
Relation.objects.create(left=r5, right=r2)
Relation.objects.create(left=r3, right=r2)
q1 = Relation.objects.filter(left__category__name__in=['First'], right__category__name__in=['Second'])
self.assertQuerysetEqual(q1, ["<Relation: First - Second>"])
q2 = Category.objects.filter(record__left_set__right__category__name='Second').order_by('name')
self.assertQuerysetEqual(q2, ["<Category: First>", "<Category: Second>"])
p = Parent.objects.create(name="Parent")
c = Child.objects.create(name="Child", parent=p)
self.assertRaises(ValueError, Child.objects.create, name="Grandchild", parent=c)
def test_fk_instantiation_outside_model(self):
# Regression for #12190 -- Should be able to instantiate a FK outside
# of a model, and interrogate its related field.
cat = models.ForeignKey(Category)
self.assertEqual('id', cat.rel.get_related_field().name)
def test_relation_unsaved(self):
# Test that the <field>_set manager does not join on Null value fields (#17541)
Third.objects.create(name='Third 1')
Third.objects.create(name='Third 2')
th = Third(name="testing")
# The object isn't saved an thus the relation field is null - we won't even
# execute a query in this case.
with self.assertNumQueries(0):
self.assertEqual(th.child_set.count(), 0)
th.save()
# Now the model is saved, so we will need to execute an query.
with self.assertNumQueries(1):
self.assertEqual(th.child_set.count(), 0)
def test_related_object(self):
public_school = School.objects.create(is_public=True)
public_student = Student.objects.create(school=public_school)
private_school = School.objects.create(is_public=False)
private_student = Student.objects.create(school=private_school)
# Only one school is available via all() due to the custom default manager.
self.assertQuerysetEqual(
School.objects.all(),
["<School: School object>"]
)
self.assertEqual(public_student.school, public_school)
# Make sure the base manager is used so that an student can still access
# its related school even if the default manager doesn't normally
# allow it.
self.assertEqual(private_student.school, private_school)
# If the manager is marked "use_for_related_fields", it'll get used instead
# of the "bare" queryset. Usually you'd define this as a property on the class,
# but this approximates that in a way that's easier in tests.
School.objects.use_for_related_fields = True
try:
private_student = Student.objects.get(pk=private_student.pk)
self.assertRaises(School.DoesNotExist, lambda: private_student.school)
finally:
School.objects.use_for_related_fields = False
def test_hasattr_related_object(self):
# The exception raised on attribute access when a related object
# doesn't exist should be an instance of a subclass of `AttributeError`
# refs #21563
self.assertFalse(hasattr(Article(), 'reporter'))