from __future__ import unicode_literals
from datetime import datetime
from operator import attrgetter
from django.db.models import F
from django.test import TestCase
from .models import Article, Author, Reference
class OrderingTests(TestCase):
def setUp(self):
self.a1 = Article.objects.create(
headline="Article 1", pub_date=datetime(2005, 7, 26)
)
self.a2 = Article.objects.create(
headline="Article 2", pub_date=datetime(2005, 7, 27)
)
self.a3 = Article.objects.create(
headline="Article 3", pub_date=datetime(2005, 7, 27)
)
self.a4 = Article.objects.create(
headline="Article 4", pub_date=datetime(2005, 7, 28)
)
def test_default_ordering(self):
"""
By default, Article.objects.all() orders by pub_date descending, then
headline ascending.
"""
self.assertQuerysetEqual(
Article.objects.all(), [
"Article 4",
"Article 2",
"Article 3",
"Article 1",
],
attrgetter("headline")
)
# Getting a single item should work too:
self.assertEqual(Article.objects.all()[0], self.a4)
def test_default_ordering_override(self):
"""
Override ordering with order_by, which is in the same format as the
ordering attribute in models.
"""
self.assertQuerysetEqual(
Article.objects.order_by("headline"), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
Article.objects.order_by("pub_date", "-headline"), [
"Article 1",
"Article 3",
"Article 2",
"Article 4",
],
attrgetter("headline")
)
def test_order_by_override(self):
"""
Only the last order_by has any effect (since they each override any
previous ordering).
"""
self.assertQuerysetEqual(
Article.objects.order_by("id"), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
Article.objects.order_by("id").order_by("-headline"), [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_stop_slicing(self):
"""
Use the 'stop' part of slicing notation to limit the results.
"""
self.assertQuerysetEqual(
Article.objects.order_by("headline")[:2], [
"Article 1",
"Article 2",
],
attrgetter("headline")
)
def test_stop_start_slicing(self):
"""
Use the 'stop' and 'start' parts of slicing notation to offset the
result list.
"""
self.assertQuerysetEqual(
Article.objects.order_by("headline")[1:3], [
"Article 2",
"Article 3",
],
attrgetter("headline")
)
def test_random_ordering(self):
"""
Use '?' to order randomly.
"""
self.assertEqual(
len(list(Article.objects.order_by("?"))), 4
)
def test_reversed_ordering(self):
"""
Ordering can be reversed using the reverse() method on a queryset.
This allows you to extract things like "the last two items" (reverse
and then take the first two).
"""
self.assertQuerysetEqual(
Article.objects.all().reverse()[:2], [
"Article 1",
"Article 3",
],
attrgetter("headline")
)
def test_reverse_ordering_pure(self):
qs1 = Article.objects.order_by(F('headline').asc())
qs2 = qs1.reverse()
self.assertQuerysetEqual(
qs1, [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
qs2, [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_extra_ordering(self):
"""
Ordering can be based on fields included from an 'extra' clause
"""
self.assertQuerysetEqual(
Article.objects.extra(select={"foo": "pub_date"}, order_by=["foo", "headline"]), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
def test_extra_ordering_quoting(self):
"""
If the extra clause uses an SQL keyword for a name, it will be
protected by quoting.
"""
self.assertQuerysetEqual(
Article.objects.extra(select={"order": "pub_date"}, order_by=["order", "headline"]), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
def test_extra_ordering_with_table_name(self):
self.assertQuerysetEqual(
Article.objects.extra(order_by=['ordering_article.headline']), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
Article.objects.extra(order_by=['-ordering_article.headline']), [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_order_by_pk(self):
"""
Ensure that 'pk' works as an ordering option in Meta.
Refs #8291.
"""
Author.objects.create(pk=1)
Author.objects.create(pk=2)
Author.objects.create(pk=3)
Author.objects.create(pk=4)
self.assertQuerysetEqual(
Author.objects.all(), [
4, 3, 2, 1
],
attrgetter("pk")
)
def test_order_by_fk_attname(self):
"""
Ensure that ordering by a foreign key by its attribute name prevents
the query from inheriting it's related model ordering option.
Refs #19195.
"""
for i in range(1, 5):
author = Author.objects.create(pk=i)
article = getattr(self, "a%d" % (5 - i))
article.author = author
article.save(update_fields={'author'})
self.assertQuerysetEqual(
Article.objects.order_by('author_id'), [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_order_by_f_expression(self):
self.assertQuerysetEqual(
Article.objects.order_by(F('headline')), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
Article.objects.order_by(F('headline').asc()), [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
self.assertQuerysetEqual(
Article.objects.order_by(F('headline').desc()), [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_order_by_f_expression_duplicates(self):
"""
A column may only be included once (the first occurrence) so we check
to ensure there are no duplicates by inspecting the SQL.
"""
qs = Article.objects.order_by(F('headline').asc(), F('headline').desc())
sql = str(qs.query).upper()
fragment = sql[sql.find('ORDER BY'):]
self.assertEqual(fragment.count('HEADLINE'), 1)
self.assertQuerysetEqual(
qs, [
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline")
)
qs = Article.objects.order_by(F('headline').desc(), F('headline').asc())
sql = str(qs.query).upper()
fragment = sql[sql.find('ORDER BY'):]
self.assertEqual(fragment.count('HEADLINE'), 1)
self.assertQuerysetEqual(
qs, [
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline")
)
def test_related_ordering_duplicate_table_reference(self):
"""
An ordering referencing a model with an ordering referencing a model
multiple time no circular reference should be detected (#24654).
"""
first_author = Author.objects.create()
second_author = Author.objects.create()
self.a1.author = first_author
self.a1.second_author = second_author
self.a1.save()
self.a2.author = second_author
self.a2.second_author = first_author
self.a2.save()
r1 = Reference.objects.create(article_id=self.a1.pk)
r2 = Reference.objects.create(article_id=self.a2.pk)
self.assertQuerysetEqual(Reference.objects.all(), [r2, r1], lambda x: x)