django1/tests/db_functions/comparison/test_coalesce.py

73 lines
2.6 KiB
Python

from django.db.models import TextField
from django.db.models.functions import Coalesce, Lower
from django.test import TestCase
from django.utils import timezone
from ..models import Article, Author
lorem_ipsum = """
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua."""
class CoalesceTests(TestCase):
def test_basic(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='Rhonda')
authors = Author.objects.annotate(display_name=Coalesce('alias', 'name'))
self.assertQuerysetEqual(
authors.order_by('name'), ['smithj', 'Rhonda'],
lambda a: a.display_name
)
def test_gt_two_expressions(self):
with self.assertRaisesMessage(ValueError, 'Coalesce must take at least two expressions'):
Author.objects.annotate(display_name=Coalesce('alias'))
def test_mixed_values(self):
a1 = Author.objects.create(name='John Smith', alias='smithj')
a2 = Author.objects.create(name='Rhonda')
ar1 = Article.objects.create(
title='How to Django',
text=lorem_ipsum,
written=timezone.now(),
)
ar1.authors.add(a1)
ar1.authors.add(a2)
# mixed Text and Char
article = Article.objects.annotate(
headline=Coalesce('summary', 'text', output_field=TextField()),
)
self.assertQuerysetEqual(
article.order_by('title'), [lorem_ipsum],
lambda a: a.headline
)
# mixed Text and Char wrapped
article = Article.objects.annotate(
headline=Coalesce(Lower('summary'), Lower('text'), output_field=TextField()),
)
self.assertQuerysetEqual(
article.order_by('title'), [lorem_ipsum.lower()],
lambda a: a.headline
)
def test_ordering(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='Rhonda')
authors = Author.objects.order_by(Coalesce('alias', 'name'))
self.assertQuerysetEqual(
authors, ['Rhonda', 'John Smith'],
lambda a: a.name
)
authors = Author.objects.order_by(Coalesce('alias', 'name').asc())
self.assertQuerysetEqual(
authors, ['Rhonda', 'John Smith'],
lambda a: a.name
)
authors = Author.objects.order_by(Coalesce('alias', 'name').desc())
self.assertQuerysetEqual(
authors, ['John Smith', 'Rhonda'],
lambda a: a.name
)