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78 lines
3.2 KiB
Python
78 lines
3.2 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"], 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(
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ValueError, "Coalesce must take at least two expressions"
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):
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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], 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(
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Lower("summary"), Lower("text"), output_field=TextField()
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),
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)
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self.assertQuerySetEqual(
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article.order_by("title"), [lorem_ipsum.lower()], 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(authors, ["Rhonda", "John Smith"], lambda a: a.name)
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authors = Author.objects.order_by(Coalesce("alias", "name").asc())
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self.assertQuerySetEqual(authors, ["Rhonda", "John Smith"], lambda a: a.name)
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authors = Author.objects.order_by(Coalesce("alias", "name").desc())
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self.assertQuerySetEqual(authors, ["John Smith", "Rhonda"], lambda a: a.name)
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def test_empty_queryset(self):
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Author.objects.create(name="John Smith")
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queryset = Author.objects.values("id")
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tests = [
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(queryset.none(), "QuerySet.none()"),
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(queryset.filter(id=0), "QuerySet.filter(id=0)"),
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(Subquery(queryset.none()), "Subquery(QuerySet.none())"),
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(Subquery(queryset.filter(id=0)), "Subquery(Queryset.filter(id=0)"),
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]
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for empty_query, description in tests:
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with self.subTest(description), self.assertNumQueries(1):
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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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