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from datetime import datetime
from operator import attrgetter
from django.test import TestCase
from models import Article
class OrderingTests(TestCase):
def test_basic(self):
a1 = Article.objects.create(
headline="Article 1", pub_date=datetime(2005, 7, 26)
)
a2 = Article.objects.create(
headline="Article 2", pub_date=datetime(2005, 7, 27)
)
a3 = Article.objects.create(
headline="Article 3", pub_date=datetime(2005, 7, 27)
)
a4 = Article.objects.create(
headline="Article 4", pub_date=datetime(2005, 7, 28)
)
# 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")
)
# 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")
)
# 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")
)
# 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")
)
# 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")
)
# Getting a single item should work too:
self.assertEqual(Article.objects.all()[0], a4)
# Use '?' to order randomly.
self.assertEqual(
len(list(Article.objects.order_by("?"))), 4
)
# 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")
)
# 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")
)
# 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")
)
|
