mirror of
				https://github.com/django/django.git
				synced 2025-10-30 00:56:09 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			93 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| from datetime import datetime, timedelta
 | |
| from decimal import Decimal
 | |
| from unittest import skipUnless
 | |
| 
 | |
| from django.db import connection
 | |
| from django.db.models.expressions import RawSQL
 | |
| from django.db.models.functions import Coalesce, Least
 | |
| from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
 | |
| from django.utils import timezone
 | |
| 
 | |
| from ..models import Article, Author, DecimalModel, Fan
 | |
| 
 | |
| 
 | |
| class LeastTests(TestCase):
 | |
| 
 | |
|     def test_basic(self):
 | |
|         now = timezone.now()
 | |
|         before = now - timedelta(hours=1)
 | |
|         Article.objects.create(title='Testing with Django', written=before, published=now)
 | |
|         articles = Article.objects.annotate(first_updated=Least('written', 'published'))
 | |
|         self.assertEqual(articles.first().first_updated, before)
 | |
| 
 | |
|     @skipUnlessDBFeature('greatest_least_ignores_nulls')
 | |
|     def test_ignores_null(self):
 | |
|         now = timezone.now()
 | |
|         Article.objects.create(title='Testing with Django', written=now)
 | |
|         articles = Article.objects.annotate(
 | |
|             first_updated=Least('written', 'published'),
 | |
|         )
 | |
|         self.assertEqual(articles.first().first_updated, now)
 | |
| 
 | |
|     @skipIfDBFeature('greatest_least_ignores_nulls')
 | |
|     def test_propagates_null(self):
 | |
|         Article.objects.create(title='Testing with Django', written=timezone.now())
 | |
|         articles = Article.objects.annotate(first_updated=Least('written', 'published'))
 | |
|         self.assertIsNone(articles.first().first_updated)
 | |
| 
 | |
|     def test_coalesce_workaround(self):
 | |
|         future = datetime(2100, 1, 1)
 | |
|         now = timezone.now()
 | |
|         Article.objects.create(title='Testing with Django', written=now)
 | |
|         articles = Article.objects.annotate(
 | |
|             last_updated=Least(
 | |
|                 Coalesce('written', future),
 | |
|                 Coalesce('published', future),
 | |
|             ),
 | |
|         )
 | |
|         self.assertEqual(articles.first().last_updated, now)
 | |
| 
 | |
|     @skipUnless(connection.vendor == 'mysql', "MySQL-specific workaround")
 | |
|     def test_coalesce_workaround_mysql(self):
 | |
|         future = datetime(2100, 1, 1)
 | |
|         now = timezone.now()
 | |
|         Article.objects.create(title='Testing with Django', written=now)
 | |
|         future_sql = RawSQL("cast(%s as datetime)", (future,))
 | |
|         articles = Article.objects.annotate(
 | |
|             last_updated=Least(
 | |
|                 Coalesce('written', future_sql),
 | |
|                 Coalesce('published', future_sql),
 | |
|             ),
 | |
|         )
 | |
|         self.assertEqual(articles.first().last_updated, now)
 | |
| 
 | |
|     def test_all_null(self):
 | |
|         Article.objects.create(title='Testing with Django', written=timezone.now())
 | |
|         articles = Article.objects.annotate(first_updated=Least('published', 'updated'))
 | |
|         self.assertIsNone(articles.first().first_updated)
 | |
| 
 | |
|     def test_one_expressions(self):
 | |
|         with self.assertRaisesMessage(ValueError, 'Least must take at least two expressions'):
 | |
|             Least('written')
 | |
| 
 | |
|     def test_related_field(self):
 | |
|         author = Author.objects.create(name='John Smith', age=45)
 | |
|         Fan.objects.create(name='Margaret', age=50, author=author)
 | |
|         authors = Author.objects.annotate(lowest_age=Least('age', 'fans__age'))
 | |
|         self.assertEqual(authors.first().lowest_age, 45)
 | |
| 
 | |
|     def test_update(self):
 | |
|         author = Author.objects.create(name='James Smith', goes_by='Jim')
 | |
|         Author.objects.update(alias=Least('name', 'goes_by'))
 | |
|         author.refresh_from_db()
 | |
|         self.assertEqual(author.alias, 'James Smith')
 | |
| 
 | |
|     def test_decimal_filter(self):
 | |
|         obj = DecimalModel.objects.create(n1=Decimal('1.1'), n2=Decimal('1.2'))
 | |
|         self.assertCountEqual(
 | |
|             DecimalModel.objects.annotate(
 | |
|                 least=Least('n1', 'n2'),
 | |
|             ).filter(least=Decimal('1.1')),
 | |
|             [obj],
 | |
|         )
 |