[1.9.x] Fixed #25535 -- Made ForeignObject checks less strict. (38d6e1e2) · Commits · Dom Sekotill / django

django/db/models/fields/related.py

+19 −6

Original line number	Diff line number	Diff line
		@@ -473,22 +473,35 @@ class ForeignObject(RelatedField):
		if not self.foreign_related_fields:
		return []

		has_unique_field = any(rel_field.unique
		for rel_field in self.foreign_related_fields)
		if not has_unique_field and len(self.foreign_related_fields) > 1:
		unique_foreign_fields = {
		frozenset([f.name])
		for f in self.remote_field.model._meta.get_fields()
		if getattr(f, 'unique', False)
		}
		unique_foreign_fields.update({
		frozenset(ut)
		for ut in self.remote_field.model._meta.unique_together
		})
		foreign_fields = {f.name for f in self.foreign_related_fields}
		has_unique_constraint = any(u <= foreign_fields for u in unique_foreign_fields)

		if not has_unique_constraint and len(self.foreign_related_fields) > 1:
		field_combination = ', '.join("'%s'" % rel_field.name
		for rel_field in self.foreign_related_fields)
		model_name = self.remote_field.model.__name__
		return [
		checks.Error(
		"None of the fields %s on model '%s' have a unique=True constraint."
		"No subset of the fields %s on model '%s' is unique."
		% (field_combination, model_name),
		hint=None,
		hint=(
		"Add unique=True on any of those fields or add at "
		"least a subset of them to a unique_together constraint."
		),
		obj=self,
		id='fields.E310',
		)
		]
		elif not has_unique_field:
		elif not has_unique_constraint:
		field_name = self.foreign_related_fields[0].name
		model_name = self.remote_field.model.__name__
		return [

docs/ref/checks.txt

+3 −2

Original line number	Diff line number	Diff line
		@@ -189,8 +189,9 @@ Related Fields
		for ``<field name>``.
		* fields.E306: Related name must be a valid Python identifier or end with
		a ``'+'``.
		* fields.E310: None of the fields ``<field1>``, ``<field2>``, ... on model
		``<model>`` have a ``unique=True`` constraint.
		* fields.E310: No subset of the fields ``<field1>``, ``<field2>``, ... on
		model ``<model>`` is unique. Add ``unique=True`` on any of those fields or
		add at least a subset of them to a unique_together constraint.
		* fields.E311: ``<model>`` must set ``unique=True`` because it is
		referenced by a ``ForeignKey``.
		* fields.E320: Field specifies ``on_delete=SET_NULL``, but cannot be null.

tests/foreign_object/tests.py

+52 −1

Original line number	Diff line number	Diff line
		@@ -2,7 +2,9 @@ import datetime
		from operator import attrgetter

		from django.core.exceptions import FieldError
		from django.test import TestCase, skipUnlessDBFeature
		from django.db import models
		from django.db.models.fields.related import ForeignObject
		from django.test import SimpleTestCase, TestCase, skipUnlessDBFeature
		from django.utils import translation

		from .models import (
		@@ -391,3 +393,52 @@ class MultiColumnFKTests(TestCase):
		""" See: https://code.djangoproject.com/ticket/21566 """
		objs = [Person(name="abcd_%s" % i, person_country=self.usa) for i in range(0, 5)]
		Person.objects.bulk_create(objs, 10)


		class TestModelCheckTests(SimpleTestCase):

		def test_check_composite_foreign_object(self):
		class Parent(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()

		class Meta:
		unique_together = (('a', 'b'),)

		class Child(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		value = models.CharField(max_length=255)
		parent = ForeignObject(
		Parent,
		on_delete=models.SET_NULL,
		from_fields=('a', 'b'),
		to_fields=('a', 'b'),
		related_name='children',
		)

		self.assertEqual(Child._meta.get_field('parent').check(from_model=Child), [])

		def test_check_subset_composite_foreign_object(self):
		class Parent(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		c = models.PositiveIntegerField()

		class Meta:
		unique_together = (('a', 'b'),)

		class Child(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		c = models.PositiveIntegerField()
		d = models.CharField(max_length=255)
		parent = ForeignObject(
		Parent,
		on_delete=models.SET_NULL,
		from_fields=('a', 'b', 'c'),
		to_fields=('a', 'b', 'c'),
		related_name='children',
		)

		self.assertEqual(Child._meta.get_field('parent').check(from_model=Child), [])

tests/invalid_models_tests/test_relative_fields.py

+80 −3

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@ import warnings

		from django.core.checks import Error, Warning as DjangoWarning
		from django.db import models
		from django.db.models.fields.related import ForeignObject
		from django.test import ignore_warnings
		from django.test.testcases import skipIfDBFeature
		from django.test.utils import override_settings
		@@ -507,9 +508,11 @@ class RelativeFieldTests(IsolatedModelsTestCase):
		errors = field.check()
		expected = [
		Error(
		"None of the fields 'country_id', 'city_id' on model 'Person' "
		"have a unique=True constraint.",
		hint=None,
		"No subset of the fields 'country_id', 'city_id' on model 'Person' is unique.",
		hint=(
		"Add unique=True on any of those fields or add at least "
		"a subset of them to a unique_together constraint."
		),
		obj=field,
		id='fields.E310',
		)
		@@ -1395,3 +1398,77 @@ class M2mThroughFieldsTests(IsolatedModelsTestCase):
		obj=field,
		id='fields.E337')]
		self.assertEqual(expected, errors)

		def test_superset_foreign_object(self):
		class Parent(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		c = models.PositiveIntegerField()

		class Meta:
		unique_together = (('a', 'b', 'c'),)

		class Child(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		value = models.CharField(max_length=255)
		parent = ForeignObject(
		Parent,
		on_delete=models.SET_NULL,
		from_fields=('a', 'b'),
		to_fields=('a', 'b'),
		related_name='children',
		)

		field = Child._meta.get_field('parent')
		errors = field.check(from_model=Child)
		expected = [
		Error(
		"No subset of the fields 'a', 'b' on model 'Parent' is unique.",
		hint=(
		"Add unique=True on any of those fields or add at least "
		"a subset of them to a unique_together constraint."
		),
		obj=field,
		id='fields.E310',
		),
		]
		self.assertEqual(expected, errors)

		def test_insersection_foreign_object(self):
		class Parent(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		c = models.PositiveIntegerField()
		d = models.PositiveIntegerField()

		class Meta:
		unique_together = (('a', 'b', 'c'),)

		class Child(models.Model):
		a = models.PositiveIntegerField()
		b = models.PositiveIntegerField()
		d = models.PositiveIntegerField()
		value = models.CharField(max_length=255)
		parent = ForeignObject(
		Parent,
		on_delete=models.SET_NULL,
		from_fields=('a', 'b', 'd'),
		to_fields=('a', 'b', 'd'),
		related_name='children',
		)

		field = Child._meta.get_field('parent')
		errors = field.check(from_model=Child)
		expected = [
		Error(
		"No subset of the fields 'a', 'b', 'd' on model 'Parent' is unique.",
		hint=(
		"Add unique=True on any of those fields or add at least "
		"a subset of them to a unique_together constraint."
		),
		obj=field,
		id='fields.E310',
		),
		]
		self.assertEqual(expected, errors)