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b2a0978610
Thanks Simon Charette for the review and implementation idea.
Backport of dd1fa3a31b from main
84 lines
3.0 KiB
Python
84 lines
3.0 KiB
Python
from django.db.models import Subquery, TextField
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from django.db.models.functions import Coalesce, Lower
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from django.test import TestCase
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from django.utils import timezone
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from ..models import Article, Author
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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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class CoalesceTests(TestCase):
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def test_basic(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'), ['smithj', 'Rhonda'],
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lambda a: a.display_name
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)
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def test_gt_two_expressions(self):
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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_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'), [lorem_ipsum],
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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'), [lorem_ipsum.lower()],
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lambda a: a.headline
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)
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def test_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, ['Rhonda', 'John Smith'],
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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, ['Rhonda', 'John Smith'],
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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, ['John Smith', 'Rhonda'],
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lambda a: a.name
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)
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def test_empty_queryset(self):
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Author.objects.create(name='John Smith')
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tests = [
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Author.objects.none(),
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Subquery(Author.objects.none()),
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]
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for empty_query in tests:
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with self.subTest(empty_query.__class__.__name__):
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qs = Author.objects.annotate(annotation=Coalesce(empty_query, 42))
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self.assertEqual(qs.first().annotation, 42)
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