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			96 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			96 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| from datetime import datetime, timedelta
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| from decimal import Decimal
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| from unittest import skipUnless
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| 
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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, Least
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| from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
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| from django.utils import timezone
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| 
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| from ..models import Article, Author, DecimalModel, Fan
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| 
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| 
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| class LeastTests(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(
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|             title="Testing with Django", written=before, published=now
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|         )
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|         articles = Article.objects.annotate(first_updated=Least("written", "published"))
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|         self.assertEqual(articles.first().first_updated, before)
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| 
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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(
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|             first_updated=Least("written", "published"),
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|         )
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|         self.assertEqual(articles.first().first_updated, now)
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| 
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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(first_updated=Least("written", "published"))
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|         self.assertIsNone(articles.first().first_updated)
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| 
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|     def test_coalesce_workaround(self):
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|         future = datetime(2100, 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=Least(
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|                 Coalesce("written", future),
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|                 Coalesce("published", future),
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|             ),
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|         )
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|         self.assertEqual(articles.first().last_updated, now)
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| 
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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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|         future = datetime(2100, 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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|         future_sql = RawSQL("cast(%s as datetime)", (future,))
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|         articles = Article.objects.annotate(
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|             last_updated=Least(
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|                 Coalesce("written", future_sql),
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|                 Coalesce("published", future_sql),
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|             ),
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|         )
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|         self.assertEqual(articles.first().last_updated, now)
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| 
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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(first_updated=Least("published", "updated"))
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|         self.assertIsNone(articles.first().first_updated)
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| 
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|     def test_one_expressions(self):
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|         with self.assertRaisesMessage(
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|             ValueError, "Least must take at least two expressions"
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|         ):
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|             Least("written")
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| 
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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(lowest_age=Least("age", "fans__age"))
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|         self.assertEqual(authors.first().lowest_age, 45)
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| 
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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=Least("name", "goes_by"))
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|         author.refresh_from_db()
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|         self.assertEqual(author.alias, "James Smith")
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| 
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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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|                 least=Least("n1", "n2"),
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|             ).filter(least=Decimal("1.1")),
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|             [obj],
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|         )
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