[5.1.x] Fixed #35638 -- Updated validate_constraints to consider db_default.

Backport of 509763c79952cde02d9f5b584af4278bdbed77b2 from main.

2 files changed, 15 insertions, 1 deletions

diff --git a/tests/validation/models.py b/tests/validation/models.py
index f6b1e0cd62..beec524758 100644
--- a/tests/validation/models.py
+++ b/tests/validation/models.py
@@ -48,7 +48,7 @@ class ModelToValidate(models.Model):
 
 class UniqueFieldsModel(models.Model):
     unique_charfield = models.CharField(max_length=100, unique=True)
-    unique_integerfield = models.IntegerField(unique=True)
+    unique_integerfield = models.IntegerField(unique=True, db_default=42)
     non_unique_field = models.IntegerField()
 
 
diff --git a/tests/validation/test_unique.py b/tests/validation/test_unique.py
index 4a8b3894f0..36ee6e9da0 100644
--- a/tests/validation/test_unique.py
+++ b/tests/validation/test_unique.py
@@ -146,6 +146,20 @@ class PerformUniqueChecksTest(TestCase):
             mtv = ModelToValidate(number=10, name="Some Name")
             mtv.full_clean()
 
+    def test_unique_db_default(self):
+        UniqueFieldsModel.objects.create(unique_charfield="foo", non_unique_field=42)
+        um = UniqueFieldsModel(unique_charfield="bar", non_unique_field=42)
+        with self.assertRaises(ValidationError) as cm:
+            um.full_clean()
+        self.assertEqual(
+            cm.exception.message_dict,
+            {
+                "unique_integerfield": [
+                    "Unique fields model with this Unique integerfield already exists."
+                ]
+            },
+        )
+
     def test_unique_for_date(self):
         Post.objects.create(
             title="Django 1.0 is released",