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from __future__ import unicode_literals
from unittest import skipUnless
from django.db import connection
from django.db.models import CharField, TextField, Value as V
from django.db.models.functions import (
Coalesce, Concat, ConcatPair, Length, Lower, Substr, Upper,
)
from django.test import TestCase
from django.utils import six, 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 FunctionTests(TestCase):
def test_coalesce(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
)
with self.assertRaisesMessage(ValueError, 'Coalesce must take at least two expressions'):
Author.objects.annotate(display_name=Coalesce('alias'))
def test_coalesce_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_coalesce_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
)
def test_concat(self):
Author.objects.create(name='Jayden')
Author.objects.create(name='John Smith', alias='smithj', goes_by='John')
Author.objects.create(name='Margaret', goes_by='Maggie')
Author.objects.create(name='Rhonda', alias='adnohR')
authors = Author.objects.annotate(joined=Concat('alias', 'goes_by'))
self.assertQuerysetEqual(
authors.order_by('name'), [
'',
'smithjJohn',
'Maggie',
'adnohR',
],
lambda a: a.joined
)
with self.assertRaisesMessage(ValueError, 'Concat must take at least two expressions'):
Author.objects.annotate(joined=Concat('alias'))
def test_concat_many(self):
Author.objects.create(name='Jayden')
Author.objects.create(name='John Smith', alias='smithj', goes_by='John')
Author.objects.create(name='Margaret', goes_by='Maggie')
Author.objects.create(name='Rhonda', alias='adnohR')
authors = Author.objects.annotate(
joined=Concat('name', V(' ('), 'goes_by', V(')'), output_field=CharField()),
)
self.assertQuerysetEqual(
authors.order_by('name'), [
'Jayden ()',
'John Smith (John)',
'Margaret (Maggie)',
'Rhonda ()',
],
lambda a: a.joined
)
def test_concat_mixed_char_text(self):
Article.objects.create(title='The Title', text=lorem_ipsum, written=timezone.now())
article = Article.objects.annotate(
title_text=Concat('title', V(' - '), 'text', output_field=TextField()),
).get(title='The Title')
self.assertEqual(article.title + ' - ' + article.text, article.title_text)
# wrap the concat in something else to ensure that we're still
# getting text rather than bytes
article = Article.objects.annotate(
title_text=Upper(Concat('title', V(' - '), 'text', output_field=TextField())),
).get(title='The Title')
expected = article.title + ' - ' + article.text
self.assertEqual(expected.upper(), article.title_text)
@skipUnless(connection.vendor == 'sqlite', "sqlite specific implementation detail.")
def test_concat_coalesce_idempotent(self):
pair = ConcatPair(V('a'), V('b'))
# Check nodes counts
self.assertEqual(len(list(pair.flatten())), 3)
self.assertEqual(len(list(pair.coalesce().flatten())), 7) # + 2 Coalesce + 2 Value()
self.assertEqual(len(list(pair.flatten())), 3)
def test_concat_sql_generation_idempotency(self):
qs = Article.objects.annotate(description=Concat('title', V(': '), 'summary'))
# Multiple compilations should not alter the generated query.
self.assertEqual(str(qs.query), str(qs.all().query))
def test_lower(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='Rhonda')
authors = Author.objects.annotate(lower_name=Lower('name'))
self.assertQuerysetEqual(
authors.order_by('name'), [
'john smith',
'rhonda',
],
lambda a: a.lower_name
)
Author.objects.update(name=Lower('name'))
self.assertQuerysetEqual(
authors.order_by('name'), [
('john smith', 'john smith'),
('rhonda', 'rhonda'),
],
lambda a: (a.lower_name, a.name)
)
def test_upper(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='Rhonda')
authors = Author.objects.annotate(upper_name=Upper('name'))
self.assertQuerysetEqual(
authors.order_by('name'), [
'JOHN SMITH',
'RHONDA',
],
lambda a: a.upper_name
)
Author.objects.update(name=Upper('name'))
self.assertQuerysetEqual(
authors.order_by('name'), [
('JOHN SMITH', 'JOHN SMITH'),
('RHONDA', 'RHONDA'),
],
lambda a: (a.upper_name, a.name)
)
def test_length(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='Rhonda')
authors = Author.objects.annotate(
name_length=Length('name'),
alias_length=Length('alias'))
self.assertQuerysetEqual(
authors.order_by('name'), [
(10, 6),
(6, None),
],
lambda a: (a.name_length, a.alias_length)
)
self.assertEqual(authors.filter(alias_length__lte=Length('name')).count(), 1)
def test_length_ordering(self):
Author.objects.create(name='John Smith', alias='smithj')
Author.objects.create(name='John Smith', alias='smithj1')
Author.objects.create(name='Rhonda', alias='ronny')
authors = Author.objects.order_by(Length('name'), Length('alias'))
self.assertQuerysetEqual(
authors, [
('Rhonda', 'ronny'),
('John Smith', 'smithj'),
('John Smith', 'smithj1'),
],
lambda a: (a.name, a.alias)
)
def test_substr(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
)
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
)
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