mirror of https://github.com/django/django.git
55 lines
1.7 KiB
Python
55 lines
1.7 KiB
Python
from unittest import skipUnless
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from django.db import connection
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from django.db.models import Value
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from django.db.models.functions import NullIf
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from django.test import TestCase
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from ..models import Author
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class NullIfTests(TestCase):
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@classmethod
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def setUpTestData(cls):
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Author.objects.create(name="John Smith", alias="smithj")
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Author.objects.create(name="Rhonda", alias="Rhonda")
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def test_basic(self):
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authors = Author.objects.annotate(nullif=NullIf("alias", "name")).values_list(
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"nullif"
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)
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self.assertCountEqual(
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authors,
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[
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("smithj",),
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(
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(
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""
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if connection.features.interprets_empty_strings_as_nulls
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else None
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),
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),
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],
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)
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def test_null_argument(self):
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authors = Author.objects.annotate(
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nullif=NullIf("name", Value(None))
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).values_list("nullif")
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self.assertCountEqual(authors, [("John Smith",), ("Rhonda",)])
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def test_too_few_args(self):
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msg = "'NullIf' takes exactly 2 arguments (1 given)"
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with self.assertRaisesMessage(TypeError, msg):
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NullIf("name")
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@skipUnless(connection.vendor == "oracle", "Oracle specific test for NULL-literal")
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def test_null_literal(self):
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msg = "Oracle does not allow Value(None) for expression1."
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with self.assertRaisesMessage(ValueError, msg):
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list(
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Author.objects.annotate(nullif=NullIf(Value(None), "name")).values_list(
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"nullif"
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)
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)
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