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			549 lines
		
	
	
	
		
			18 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			549 lines
		
	
	
	
		
			18 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
from __future__ import unicode_literals
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from datetime import datetime, timedelta
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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 import CharField, TextField, Value as V
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from django.db.models.expressions import RawSQL
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from django.db.models.functions import (
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    Coalesce, Concat, Greatest, Least, Length, Lower, Now, Substr, Upper,
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)
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from django.test import TestCase, skipIfDBFeature, skipUnlessDBFeature
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from django.utils import six, timezone
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from .models import Article, Author, Fan
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lorem_ipsum = """
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    Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
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    tempor incididunt ut labore et dolore magna aliqua."""
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def truncate_microseconds(value):
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    return value if connection.features.supports_microsecond_precision else value.replace(microsecond=0)
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class FunctionTests(TestCase):
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    def test_coalesce(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.annotate(display_name=Coalesce('alias', 'name'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                'smithj',
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                'Rhonda',
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            ],
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            lambda a: a.display_name
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        )
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        with self.assertRaisesMessage(ValueError, 'Coalesce must take at least two expressions'):
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            Author.objects.annotate(display_name=Coalesce('alias'))
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    def test_coalesce_mixed_values(self):
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        a1 = Author.objects.create(name='John Smith', alias='smithj')
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        a2 = Author.objects.create(name='Rhonda')
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        ar1 = Article.objects.create(
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            title="How to Django",
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            text=lorem_ipsum,
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            written=timezone.now(),
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        )
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        ar1.authors.add(a1)
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        ar1.authors.add(a2)
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        # mixed Text and Char
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        article = Article.objects.annotate(
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            headline=Coalesce('summary', 'text', output_field=TextField()),
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        )
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        self.assertQuerysetEqual(
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            article.order_by('title'), [
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                lorem_ipsum,
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            ],
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            lambda a: a.headline
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        )
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        # mixed Text and Char wrapped
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        article = Article.objects.annotate(
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            headline=Coalesce(Lower('summary'), Lower('text'), output_field=TextField()),
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        )
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        self.assertQuerysetEqual(
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            article.order_by('title'), [
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                lorem_ipsum.lower(),
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            ],
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            lambda a: a.headline
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        )
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    def test_coalesce_ordering(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.order_by(Coalesce('alias', 'name'))
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        self.assertQuerysetEqual(
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            authors, [
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                'Rhonda',
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                'John Smith',
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            ],
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            lambda a: a.name
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        )
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        authors = Author.objects.order_by(Coalesce('alias', 'name').asc())
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        self.assertQuerysetEqual(
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            authors, [
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                'Rhonda',
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                'John Smith',
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            ],
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            lambda a: a.name
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        )
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        authors = Author.objects.order_by(Coalesce('alias', 'name').desc())
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        self.assertQuerysetEqual(
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            authors, [
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                'John Smith',
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                'Rhonda',
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            ],
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            lambda a: a.name
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        )
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    def test_greatest(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",
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            written=before,
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            published=now,
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        )
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        articles = Article.objects.annotate(
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            last_updated=Greatest('written', 'published'),
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        )
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        self.assertEqual(articles.first().last_updated, truncate_microseconds(now))
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    @skipUnlessDBFeature('greatest_least_ignores_nulls')
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    def test_greatest_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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            last_updated=Greatest('written', 'published'),
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        )
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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_greatest_propogates_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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            last_updated=Greatest('written', 'published'),
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        )
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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_greatest_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_greatest_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, truncate_microseconds(now))
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    def test_greatest_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_greatest_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_greatest_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(
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            highest_age=Greatest('age', 'fans__age'),
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        )
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        self.assertEqual(authors.first().highest_age, 50)
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    def test_greatest_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_least(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",
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            written=before,
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            published=now,
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        )
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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, truncate_microseconds(before))
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    @skipUnlessDBFeature('greatest_least_ignores_nulls')
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    def test_least_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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    @skipIfDBFeature('greatest_least_ignores_nulls')
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    def test_least_propogates_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.assertIsNone(articles.first().first_updated)
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    @skipIf(connection.vendor == 'mysql', "This doesn't work on MySQL")
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    def test_least_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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    @skipUnless(connection.vendor == 'mysql', "MySQL-specific workaround")
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    def test_least_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, truncate_microseconds(now))
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    def test_least_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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    def test_least_one_expressions(self):
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        with self.assertRaisesMessage(ValueError, 'Least must take at least two expressions'):
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            Least('written')
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    def test_least_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(
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            lowest_age=Least('age', 'fans__age'),
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        )
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        self.assertEqual(authors.first().lowest_age, 45)
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    def test_least_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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    def test_concat(self):
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        Author.objects.create(name='Jayden')
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        Author.objects.create(name='John Smith', alias='smithj', goes_by='John')
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        Author.objects.create(name='Margaret', goes_by='Maggie')
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        Author.objects.create(name='Rhonda', alias='adnohR')
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        authors = Author.objects.annotate(joined=Concat('alias', 'goes_by'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                '',
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                'smithjJohn',
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                'Maggie',
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                'adnohR',
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            ],
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            lambda a: a.joined
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        )
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        with self.assertRaisesMessage(ValueError, 'Concat must take at least two expressions'):
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            Author.objects.annotate(joined=Concat('alias'))
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    def test_concat_many(self):
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        Author.objects.create(name='Jayden')
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        Author.objects.create(name='John Smith', alias='smithj', goes_by='John')
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        Author.objects.create(name='Margaret', goes_by='Maggie')
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        Author.objects.create(name='Rhonda', alias='adnohR')
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        authors = Author.objects.annotate(
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            joined=Concat('name', V(' ('), 'goes_by', V(')'), output_field=CharField()),
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        )
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                'Jayden ()',
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                'John Smith (John)',
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                'Margaret (Maggie)',
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                'Rhonda ()',
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            ],
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            lambda a: a.joined
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        )
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    def test_concat_mixed_char_text(self):
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        Article.objects.create(title='The Title', text=lorem_ipsum, written=timezone.now())
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        article = Article.objects.annotate(
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            title_text=Concat('title', V(' - '), 'text', output_field=TextField()),
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        ).get(title='The Title')
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        self.assertEqual(article.title + ' - ' + article.text, article.title_text)
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        # wrap the concat in something else to ensure that we're still
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        # getting text rather than bytes
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        article = Article.objects.annotate(
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            title_text=Upper(Concat('title', V(' - '), 'text', output_field=TextField())),
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        ).get(title='The Title')
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        expected = article.title + ' - ' + article.text
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        self.assertEqual(expected.upper(), article.title_text)
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    def test_lower(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.annotate(lower_name=Lower('name'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                'john smith',
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                'rhonda',
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            ],
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            lambda a: a.lower_name
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        )
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        Author.objects.update(name=Lower('name'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                ('john smith', 'john smith'),
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                ('rhonda', 'rhonda'),
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            ],
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            lambda a: (a.lower_name, a.name)
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        )
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    def test_upper(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.annotate(upper_name=Upper('name'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                'JOHN SMITH',
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                'RHONDA',
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            ],
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            lambda a: a.upper_name
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        )
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        Author.objects.update(name=Upper('name'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                ('JOHN SMITH', 'JOHN SMITH'),
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                ('RHONDA', 'RHONDA'),
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            ],
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            lambda a: (a.upper_name, a.name)
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        )
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    def test_length(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.annotate(
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            name_length=Length('name'),
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            alias_length=Length('alias'))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                (10, 6),
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                (6, None),
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            ],
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            lambda a: (a.name_length, a.alias_length)
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        )
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        self.assertEqual(authors.filter(alias_length__lte=Length('name')).count(), 1)
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    def test_length_ordering(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='John Smith', alias='smithj1')
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        Author.objects.create(name='Rhonda', alias='ronny')
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        authors = Author.objects.order_by(Length('name'), Length('alias'))
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        self.assertQuerysetEqual(
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            authors, [
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                ('Rhonda', 'ronny'),
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                ('John Smith', 'smithj'),
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                ('John Smith', 'smithj1'),
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            ],
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            lambda a: (a.name, a.alias)
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        )
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    def test_substr(self):
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        Author.objects.create(name='John Smith', alias='smithj')
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        Author.objects.create(name='Rhonda')
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        authors = Author.objects.annotate(name_part=Substr('name', 5, 3))
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        self.assertQuerysetEqual(
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            authors.order_by('name'), [
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                ' Sm',
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                'da',
 | 
						|
            ],
 | 
						|
            lambda a: a.name_part
 | 
						|
        )
 | 
						|
 | 
						|
        authors = Author.objects.annotate(name_part=Substr('name', 2))
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            authors.order_by('name'), [
 | 
						|
                'ohn Smith',
 | 
						|
                'honda',
 | 
						|
            ],
 | 
						|
            lambda a: a.name_part
 | 
						|
        )
 | 
						|
 | 
						|
        # if alias is null, set to first 5 lower characters of the name
 | 
						|
        Author.objects.filter(alias__isnull=True).update(
 | 
						|
            alias=Lower(Substr('name', 1, 5)),
 | 
						|
        )
 | 
						|
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            authors.order_by('name'), [
 | 
						|
                'smithj',
 | 
						|
                'rhond',
 | 
						|
            ],
 | 
						|
            lambda a: a.alias
 | 
						|
        )
 | 
						|
 | 
						|
    def test_substr_start(self):
 | 
						|
        Author.objects.create(name='John Smith', alias='smithj')
 | 
						|
        a = Author.objects.annotate(
 | 
						|
            name_part_1=Substr('name', 1),
 | 
						|
            name_part_2=Substr('name', 2),
 | 
						|
        ).get(alias='smithj')
 | 
						|
 | 
						|
        self.assertEqual(a.name_part_1[1:], a.name_part_2)
 | 
						|
 | 
						|
        with six.assertRaisesRegex(self, ValueError, "'pos' must be greater than 0"):
 | 
						|
            Author.objects.annotate(raises=Substr('name', 0))
 | 
						|
 | 
						|
    def test_substr_with_expressions(self):
 | 
						|
        Author.objects.create(name='John Smith', alias='smithj')
 | 
						|
        Author.objects.create(name='Rhonda')
 | 
						|
        authors = Author.objects.annotate(name_part=Substr('name', 5, 3))
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            authors.order_by('name'), [
 | 
						|
                ' Sm',
 | 
						|
                'da',
 | 
						|
            ],
 | 
						|
            lambda a: a.name_part
 | 
						|
        )
 | 
						|
 | 
						|
    def test_nested_function_ordering(self):
 | 
						|
        Author.objects.create(name='John Smith')
 | 
						|
        Author.objects.create(name='Rhonda Simpson', alias='ronny')
 | 
						|
 | 
						|
        authors = Author.objects.order_by(Length(Coalesce('alias', 'name')))
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            authors, [
 | 
						|
                'Rhonda Simpson',
 | 
						|
                'John Smith',
 | 
						|
            ],
 | 
						|
            lambda a: a.name
 | 
						|
        )
 | 
						|
 | 
						|
        authors = Author.objects.order_by(Length(Coalesce('alias', 'name')).desc())
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            authors, [
 | 
						|
                'John Smith',
 | 
						|
                'Rhonda Simpson',
 | 
						|
            ],
 | 
						|
            lambda a: a.name
 | 
						|
        )
 | 
						|
 | 
						|
    def test_now(self):
 | 
						|
        ar1 = Article.objects.create(
 | 
						|
            title='How to Django',
 | 
						|
            text=lorem_ipsum,
 | 
						|
            written=timezone.now(),
 | 
						|
        )
 | 
						|
        ar2 = Article.objects.create(
 | 
						|
            title='How to Time Travel',
 | 
						|
            text=lorem_ipsum,
 | 
						|
            written=timezone.now(),
 | 
						|
        )
 | 
						|
 | 
						|
        num_updated = Article.objects.filter(id=ar1.id, published=None).update(published=Now())
 | 
						|
        self.assertEqual(num_updated, 1)
 | 
						|
 | 
						|
        num_updated = Article.objects.filter(id=ar1.id, published=None).update(published=Now())
 | 
						|
        self.assertEqual(num_updated, 0)
 | 
						|
 | 
						|
        ar1.refresh_from_db()
 | 
						|
        self.assertIsInstance(ar1.published, datetime)
 | 
						|
 | 
						|
        ar2.published = Now() + timedelta(days=2)
 | 
						|
        ar2.save()
 | 
						|
        ar2.refresh_from_db()
 | 
						|
        self.assertIsInstance(ar2.published, datetime)
 | 
						|
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            Article.objects.filter(published__lte=Now()),
 | 
						|
            ['How to Django'],
 | 
						|
            lambda a: a.title
 | 
						|
        )
 | 
						|
        self.assertQuerysetEqual(
 | 
						|
            Article.objects.filter(published__gt=Now()),
 | 
						|
            ['How to Time Travel'],
 | 
						|
            lambda a: a.title
 | 
						|
        )
 |