[3.2.x] Fixed #32453 -- Added introspection of unique constraint field ordering on SQLite.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

Backport of 4d99375b46 from master

django/db/backends/sqlite3/introspection.py

@@ -413,7 +413,7 @@ class DatabaseIntrospection(BaseDatabaseIntrospection):
                     }
                 constraints[index]['columns'].append(column)
             # Add type and column orders for indexes
-            if constraints[index]['index'] and not constraints[index]['unique']:
+            if constraints[index]['index']:
                 # SQLite doesn't support any index type other than b-tree
                 constraints[index]['type'] = Index.suffix
                 orders = self._get_index_columns_orders(sql)

tests/introspection/models.py

@@ -80,3 +80,18 @@ class CheckConstraintModel(models.Model):
         constraints = [
             models.CheckConstraint(name='up_votes_gte_0_check', check=models.Q(up_votes__gte=0)),
         ]
+
+
+class UniqueConstraintConditionModel(models.Model):
+    name = models.CharField(max_length=255)
+    color = models.CharField(max_length=32, null=True)
+
+    class Meta:
+        required_db_features = {'supports_partial_indexes'}
+        constraints = [
+            models.UniqueConstraint(
+                fields=['name'],
+                name='cond_name_without_color_uniq',
+                condition=models.Q(color__isnull=True),
+            ),
+        ]

tests/introspection/tests.py

@@ -6,7 +6,7 @@ from django.test import TransactionTestCase, skipUnlessDBFeature
 
 from .models import (
     Article, ArticleReporter, CheckConstraintModel, City, Comment, Country,
-    District, Reporter,
+    District, Reporter, UniqueConstraintConditionModel,
 )
 
 
@@ -221,6 +221,19 @@ class IntrospectionTests(TransactionTestCase):
                 indexes_verified += 1
         self.assertEqual(indexes_verified, len(expected_columns))
 
+    @skipUnlessDBFeature('supports_index_column_ordering', 'supports_partial_indexes')
+    def test_get_constraints_unique_indexes_orders(self):
+        with connection.cursor() as cursor:
+            constraints = connection.introspection.get_constraints(
+                cursor,
+                UniqueConstraintConditionModel._meta.db_table,
+            )
+        self.assertIn('cond_name_without_color_uniq', constraints)
+        constraint = constraints['cond_name_without_color_uniq']
+        self.assertIs(constraint['unique'], True)
+        self.assertEqual(constraint['columns'], ['name'])
+        self.assertEqual(constraint['orders'], ['ASC'])
+
     def test_get_constraints(self):
         def assertDetails(details, cols, primary_key=False, unique=False, index=False, check=False, foreign_key=None):
             # Different backends have different values for same constraints: