mirror of https://github.com/django/django.git
92 lines
3.7 KiB
Python
92 lines
3.7 KiB
Python
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from datetime import datetime, timedelta
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from decimal import Decimal
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from unittest import skipIf, skipUnless
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from django.db import connection
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from django.db.models.expressions import RawSQL
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from django.db.models.functions import Coalesce, Greatest
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from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
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from django.utils import timezone
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from ..models import Article, Author, DecimalModel, Fan
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class GreatestTests(TestCase):
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def test_basic(self):
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now = timezone.now()
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before = now - timedelta(hours=1)
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Article.objects.create(title='Testing with Django', written=before, published=now)
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articles = Article.objects.annotate(last_updated=Greatest('written', 'published'))
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self.assertEqual(articles.first().last_updated, now)
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@skipUnlessDBFeature('greatest_least_ignores_nulls')
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def test_ignores_null(self):
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now = timezone.now()
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Article.objects.create(title='Testing with Django', written=now)
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articles = Article.objects.annotate(last_updated=Greatest('written', 'published'))
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self.assertEqual(articles.first().last_updated, now)
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@skipIfDBFeature('greatest_least_ignores_nulls')
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def test_propagates_null(self):
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Article.objects.create(title='Testing with Django', written=timezone.now())
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articles = Article.objects.annotate(last_updated=Greatest('written', 'published'))
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self.assertIsNone(articles.first().last_updated)
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@skipIf(connection.vendor == 'mysql', "This doesn't work on MySQL")
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def test_coalesce_workaround(self):
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past = datetime(1900, 1, 1)
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now = timezone.now()
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Article.objects.create(title='Testing with Django', written=now)
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articles = Article.objects.annotate(
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last_updated=Greatest(
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Coalesce('written', past),
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Coalesce('published', past),
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),
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)
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self.assertEqual(articles.first().last_updated, now)
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@skipUnless(connection.vendor == 'mysql', "MySQL-specific workaround")
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def test_coalesce_workaround_mysql(self):
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past = datetime(1900, 1, 1)
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now = timezone.now()
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Article.objects.create(title='Testing with Django', written=now)
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past_sql = RawSQL("cast(%s as datetime)", (past,))
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articles = Article.objects.annotate(
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last_updated=Greatest(
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Coalesce('written', past_sql),
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Coalesce('published', past_sql),
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),
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)
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self.assertEqual(articles.first().last_updated, now)
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def test_all_null(self):
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Article.objects.create(title='Testing with Django', written=timezone.now())
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articles = Article.objects.annotate(last_updated=Greatest('published', 'updated'))
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self.assertIsNone(articles.first().last_updated)
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def test_one_expressions(self):
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with self.assertRaisesMessage(ValueError, 'Greatest must take at least two expressions'):
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Greatest('written')
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def test_related_field(self):
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author = Author.objects.create(name='John Smith', age=45)
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Fan.objects.create(name='Margaret', age=50, author=author)
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authors = Author.objects.annotate(highest_age=Greatest('age', 'fans__age'))
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self.assertEqual(authors.first().highest_age, 50)
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def test_update(self):
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author = Author.objects.create(name='James Smith', goes_by='Jim')
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Author.objects.update(alias=Greatest('name', 'goes_by'))
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author.refresh_from_db()
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self.assertEqual(author.alias, 'Jim')
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def test_decimal_filter(self):
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obj = DecimalModel.objects.create(n1=Decimal('1.1'), n2=Decimal('1.2'))
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self.assertCountEqual(
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DecimalModel.objects.annotate(
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greatest=Greatest('n1', 'n2'),
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).filter(greatest=Decimal('1.2')),
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[obj],
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)
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