django/tests/ordering/tests.py

553 lines
18 KiB
Python

from datetime import datetime
from operator import attrgetter
from django.db.models import (
CharField,
Count,
DateTimeField,
F,
Max,
OuterRef,
Subquery,
Value,
)
from django.db.models.functions import Upper
from django.test import TestCase
from .models import Article, Author, ChildArticle, OrderedByFArticle, Reference
class OrderingTests(TestCase):
@classmethod
def setUpTestData(cls):
cls.a1 = Article.objects.create(
headline="Article 1", pub_date=datetime(2005, 7, 26)
)
cls.a2 = Article.objects.create(
headline="Article 2", pub_date=datetime(2005, 7, 27)
)
cls.a3 = Article.objects.create(
headline="Article 3", pub_date=datetime(2005, 7, 27)
)
cls.a4 = Article.objects.create(
headline="Article 4", pub_date=datetime(2005, 7, 28)
)
cls.author_1 = Author.objects.create(name="Name 1")
cls.author_2 = Author.objects.create(name="Name 2")
for i in range(2):
Author.objects.create()
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_order_by_nulls_first_and_last(self):
msg = "nulls_first and nulls_last are mutually exclusive"
with self.assertRaisesMessage(ValueError, msg):
Article.objects.order_by(
F("author").desc(nulls_last=True, nulls_first=True)
)
def assertQuerysetEqualReversible(self, queryset, sequence):
self.assertSequenceEqual(queryset, sequence)
self.assertSequenceEqual(queryset.reverse(), list(reversed(sequence)))
def test_order_by_nulls_last(self):
Article.objects.filter(headline="Article 3").update(author=self.author_1)
Article.objects.filter(headline="Article 4").update(author=self.author_2)
# asc and desc are chainable with nulls_last.
self.assertQuerysetEqualReversible(
Article.objects.order_by(F("author").desc(nulls_last=True), "headline"),
[self.a4, self.a3, self.a1, self.a2],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(F("author").asc(nulls_last=True), "headline"),
[self.a3, self.a4, self.a1, self.a2],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(
Upper("author__name").desc(nulls_last=True), "headline"
),
[self.a4, self.a3, self.a1, self.a2],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(
Upper("author__name").asc(nulls_last=True), "headline"
),
[self.a3, self.a4, self.a1, self.a2],
)
def test_order_by_nulls_first(self):
Article.objects.filter(headline="Article 3").update(author=self.author_1)
Article.objects.filter(headline="Article 4").update(author=self.author_2)
# asc and desc are chainable with nulls_first.
self.assertQuerysetEqualReversible(
Article.objects.order_by(F("author").asc(nulls_first=True), "headline"),
[self.a1, self.a2, self.a3, self.a4],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(F("author").desc(nulls_first=True), "headline"),
[self.a1, self.a2, self.a4, self.a3],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(
Upper("author__name").asc(nulls_first=True), "headline"
),
[self.a1, self.a2, self.a3, self.a4],
)
self.assertQuerysetEqualReversible(
Article.objects.order_by(
Upper("author__name").desc(nulls_first=True), "headline"
),
[self.a1, self.a2, self.a4, self.a3],
)
def test_orders_nulls_first_on_filtered_subquery(self):
Article.objects.filter(headline="Article 1").update(author=self.author_1)
Article.objects.filter(headline="Article 2").update(author=self.author_1)
Article.objects.filter(headline="Article 4").update(author=self.author_2)
Author.objects.filter(name__isnull=True).delete()
author_3 = Author.objects.create(name="Name 3")
article_subquery = (
Article.objects.filter(
author=OuterRef("pk"),
headline__icontains="Article",
)
.order_by()
.values("author")
.annotate(
last_date=Max("pub_date"),
)
.values("last_date")
)
self.assertQuerysetEqualReversible(
Author.objects.annotate(
last_date=Subquery(article_subquery, output_field=DateTimeField())
)
.order_by(F("last_date").asc(nulls_first=True))
.distinct(),
[author_3, self.author_1, self.author_2],
)
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.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(
qs2,
[
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
attrgetter("headline"),
)
self.assertQuerysetEqual(
qs1,
[
"Article 1",
"Article 2",
"Article 3",
"Article 4",
],
attrgetter("headline"),
)
def test_reverse_meta_ordering_pure(self):
Article.objects.create(
headline="Article 5",
pub_date=datetime(2005, 7, 30),
author=self.author_1,
second_author=self.author_2,
)
Article.objects.create(
headline="Article 5",
pub_date=datetime(2005, 7, 30),
author=self.author_2,
second_author=self.author_1,
)
self.assertQuerysetEqual(
Article.objects.filter(headline="Article 5").reverse(),
["Name 2", "Name 1"],
attrgetter("author.name"),
)
self.assertQuerysetEqual(
Article.objects.filter(headline="Article 5"),
["Name 1", "Name 2"],
attrgetter("author.name"),
)
def test_no_reordering_after_slicing(self):
msg = "Cannot reverse a query once a slice has been taken."
qs = Article.objects.all()[0:2]
with self.assertRaisesMessage(TypeError, msg):
qs.reverse()
with self.assertRaisesMessage(TypeError, msg):
qs.last()
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):
"""
'pk' works as an ordering option in Meta.
"""
self.assertEqual(
[a.pk for a in Author.objects.all()],
[a.pk for a in Author.objects.order_by("-pk")],
)
def test_order_by_fk_attname(self):
"""
ordering by a foreign key by its attribute name prevents the query
from inheriting its related model ordering option (#19195).
"""
authors = list(Author.objects.order_by("id"))
for i in range(1, 5):
author = authors[i - 1]
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_self_referential_fk(self):
self.a1.author = Author.objects.create(editor=self.author_1)
self.a1.save()
self.a2.author = Author.objects.create(editor=self.author_2)
self.a2.save()
self.assertQuerysetEqual(
Article.objects.filter(author__isnull=False).order_by("author__editor"),
["Article 2", "Article 1"],
attrgetter("headline"),
)
self.assertQuerysetEqual(
Article.objects.filter(author__isnull=False).order_by("author__editor_id"),
["Article 1", "Article 2"],
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_order_by_constant_value(self):
# Order by annotated constant from selected columns.
qs = Article.objects.annotate(
constant=Value("1", output_field=CharField()),
).order_by("constant", "-headline")
self.assertSequenceEqual(qs, [self.a4, self.a3, self.a2, self.a1])
# Order by annotated constant which is out of selected columns.
self.assertSequenceEqual(
qs.values_list("headline", flat=True),
[
"Article 4",
"Article 3",
"Article 2",
"Article 1",
],
)
# Order by constant.
qs = Article.objects.order_by(Value("1", output_field=CharField()), "-headline")
self.assertSequenceEqual(qs, [self.a4, self.a3, self.a2, self.a1])
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.assertSequenceEqual(Reference.objects.all(), [r2, r1])
def test_default_ordering_by_f_expression(self):
"""F expressions can be used in Meta.ordering."""
articles = OrderedByFArticle.objects.all()
articles.filter(headline="Article 2").update(author=self.author_2)
articles.filter(headline="Article 3").update(author=self.author_1)
self.assertQuerysetEqual(
articles,
["Article 1", "Article 4", "Article 3", "Article 2"],
attrgetter("headline"),
)
def test_order_by_ptr_field_with_default_ordering_by_expression(self):
ca1 = ChildArticle.objects.create(
headline="h2",
pub_date=datetime(2005, 7, 27),
author=self.author_2,
)
ca2 = ChildArticle.objects.create(
headline="h2",
pub_date=datetime(2005, 7, 27),
author=self.author_1,
)
ca3 = ChildArticle.objects.create(
headline="h3",
pub_date=datetime(2005, 7, 27),
author=self.author_1,
)
ca4 = ChildArticle.objects.create(headline="h1", pub_date=datetime(2005, 7, 28))
articles = ChildArticle.objects.order_by("article_ptr")
self.assertSequenceEqual(articles, [ca4, ca2, ca1, ca3])
def test_default_ordering_does_not_affect_group_by(self):
Article.objects.exclude(headline="Article 4").update(author=self.author_1)
Article.objects.filter(headline="Article 4").update(author=self.author_2)
articles = Article.objects.values("author").annotate(count=Count("author"))
self.assertCountEqual(
articles,
[
{"author": self.author_1.pk, "count": 3},
{"author": self.author_2.pk, "count": 1},
],
)