from datetime import datetime
from django.test import TestCase
from django.core.exceptions import FieldError
from models import Article, Reporter
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(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(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(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(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(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.
self.assertRaises(TypeError, 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(2005, 7, 29))
new_article2 = self.r2.article_set.create(headline="Paul's story",
pub_date=datetime(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):
new_article = self.r.article_set.create(headline="John's second story",
pub_date=datetime(2005, 7, 29))
new_article2 = self.r2.article_set.create(headline="Paul's story",
pub_date=datetime(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.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'" % u'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>",
])
# You need two underscores between "reporter" and "id" -- not one.
self.assertRaises(FieldError, Article.objects.filter, reporter_id__exact=self.r.id)
# You need to specify a comparison clause
self.assertRaises(FieldError, Article.objects.filter, reporter_id=self.r.id)
def test_reverse_selects(self):
a3 = Article.objects.create(id=None, headline="Third article",
pub_date=datetime(2005, 7, 27), reporter_id=self.r.id)
a4 = Article.objects.create(id=None, headline="Fourth article",
pub_date=datetime(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>"])
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>",
])
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': u'John', 'reporter__last_name': u'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')
a1 = Article.objects.create(headline='First', pub_date=datetime(1980, 4, 23), reporter=r1)
a2 = Article.objects.create(headline='Second', pub_date=datetime(1980, 4, 23), reporter=r2)
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'day')),
[
datetime(1980, 4, 23, 0, 0),
datetime(2005, 7, 27, 0, 0),
])
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'month')),
[
datetime(1980, 4, 1, 0, 0),
datetime(2005, 7, 1, 0, 0),
])
self.assertEqual(list(Article.objects.select_related().dates('pub_date', 'year')),
[
datetime(1980, 1, 1, 0, 0),
datetime(2005, 1, 1, 0, 0),
])
def test_delete(self):
new_article = self.r.article_set.create(headline="John's second story",
pub_date=datetime(2005, 7, 29))
new_article2 = self.r2.article_set.create(headline="Paul's story",
pub_date=datetime(2006, 1, 17))
a3 = Article.objects.create(id=None, headline="Third article",
pub_date=datetime(2005, 7, 27), reporter_id=self.r.id)
a4 = Article.objects.create(id=None, headline="Fourth article",
pub_date=datetime(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_regression_12876(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)
from copy import deepcopy
self.assertEqual(repr(deepcopy(self.r)), "<Reporter: John Smith>")