From 3434dbd39d373df7193ad006b970c09c1a909ea3 Mon Sep 17 00:00:00 2001
From: Simon Charette <charette.s@gmail.com>
Date: Wed, 2 Aug 2023 20:47:49 -0400
Subject: [PATCH] Fixed #34754 -- Fixed JSONField check constraints validation
on NULL values.
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The __isnull lookup of JSONField must special case
Value(None, JSONField()) left-hand-side in order to be coherent with
its convoluted null handling.
Since psycopg>=3 offers no way to pass a NULL::jsonb the issue is
resolved by optimizing IsNull(Value(None), True | False) to
True | False.
Regression in 5c23d9f0c32f166c81ecb6f3f01d5077a6084318.
Thanks Alexandre Collet for the report.
---
django/db/models/lookups.py | 5 +++++
docs/releases/4.2.5.txt | 4 +++-
tests/constraints/models.py | 7 +++++++
tests/constraints/tests.py | 20 ++++++++++++++++++++
4 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/django/db/models/lookups.py b/django/db/models/lookups.py
index 91342a864a..8528fcda5c 100644
--- a/django/db/models/lookups.py
+++ b/django/db/models/lookups.py
@@ -607,6 +607,11 @@ class IsNull(BuiltinLookup):
raise ValueError(
"The QuerySet value for an isnull lookup must be True or False."
)
+ if isinstance(self.lhs, Value) and self.lhs.value is None:
+ if self.rhs:
+ raise FullResultSet
+ else:
+ raise EmptyResultSet
sql, params = self.process_lhs(compiler, connection)
if self.rhs:
return "%s IS NULL" % sql, params
diff --git a/docs/releases/4.2.5.txt b/docs/releases/4.2.5.txt
index a4e2471158..23ba728da5 100644
--- a/docs/releases/4.2.5.txt
+++ b/docs/releases/4.2.5.txt
@@ -9,4 +9,6 @@ Django 4.2.5 fixes several bugs in 4.2.4.
Bugfixes
========
-* ...
+* Fixed a regression in Django 4.2 that caused an incorrect validation of
+ ``CheckConstraints`` on ``__isnull`` lookups against ``JSONField``
+ (:ticket:`34754`).
diff --git a/tests/constraints/models.py b/tests/constraints/models.py
index ab3d4dc1e0..3ea5cf2323 100644
--- a/tests/constraints/models.py
+++ b/tests/constraints/models.py
@@ -121,3 +121,10 @@ class AbstractModel(models.Model):
class ChildModel(AbstractModel):
pass
+
+
+class JSONFieldModel(models.Model):
+ data = models.JSONField(null=True)
+
+ class Meta:
+ required_db_features = {"supports_json_field"}
diff --git a/tests/constraints/tests.py b/tests/constraints/tests.py
index 7e3d20e40c..f6571084b0 100644
--- a/tests/constraints/tests.py
+++ b/tests/constraints/tests.py
@@ -13,6 +13,7 @@ from django.utils.deprecation import RemovedInDjango60Warning
from .models import (
ChildModel,
ChildUniqueConstraintProduct,
+ JSONFieldModel,
Product,
UniqueConstraintConditionProduct,
UniqueConstraintDeferrable,
@@ -332,6 +333,25 @@ class CheckConstraintTests(TestCase):
)
constraint.validate(Product, Product())
+ @skipUnlessDBFeature("supports_json_field")
+ def test_validate_nullable_jsonfield(self):
+ is_null_constraint = models.CheckConstraint(
+ check=models.Q(data__isnull=True),
+ name="nullable_data",
+ )
+ is_not_null_constraint = models.CheckConstraint(
+ check=models.Q(data__isnull=False),
+ name="nullable_data",
+ )
+ is_null_constraint.validate(JSONFieldModel, JSONFieldModel(data=None))
+ msg = f"Constraint “{is_null_constraint.name}” is violated."
+ with self.assertRaisesMessage(ValidationError, msg):
+ is_null_constraint.validate(JSONFieldModel, JSONFieldModel(data={}))
+ msg = f"Constraint “{is_not_null_constraint.name}” is violated."
+ with self.assertRaisesMessage(ValidationError, msg):
+ is_not_null_constraint.validate(JSONFieldModel, JSONFieldModel(data=None))
+ is_not_null_constraint.validate(JSONFieldModel, JSONFieldModel(data={}))
+
class UniqueConstraintTests(TestCase):
@classmethod