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

Backport of 509763c79952cde02d9f5b584af4278bdbed77b2 from main.

1 files changed, 14 insertions, 0 deletions

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",