Fix whitespace in CREATE INDEX SQL for index suffixes

Ensure proper spacing before DESC and after opclasses in generated
CREATE INDEX statements. This improves SQL readability and resolves
formatting quirks introduced by previous fixes.

Refs #30903.

django/db/backends/ddl_references.py

@@ -83,10 +83,14 @@ class Columns(TableColumns):
 
     def __str__(self):
         def col_str(column, idx):
+            col = self.quote_name(column)
             try:
-                return self.quote_name(column) + self.col_suffixes[idx]
+                suffix = self.col_suffixes[idx]
+                if suffix:
+                    col = '{} {}'.format(col, suffix)
             except IndexError:
-                return self.quote_name(column)
+                pass
+            return col
 
         return ', '.join(col_str(column, idx) for idx, column in enumerate(self.columns))
 
@@ -114,7 +118,9 @@ class IndexColumns(Columns):
             # length as self.columns.
             col = '{} {}'.format(self.quote_name(column), self.opclasses[idx])
             try:
-                col = '{} {}'.format(col, self.col_suffixes[idx])
+                suffix = self.col_suffixes[idx]
+                if suffix:
+                    col = '{} {}'.format(col, suffix)
             except IndexError:
                 pass
             return col

tests/indexes/tests.py

@@ -75,6 +75,15 @@ class SchemaIndexesTests(TestCase):
         index_sql = connection.schema_editor()._model_indexes_sql(IndexTogetherSingleList)
         self.assertEqual(len(index_sql), 1)
 
+    def test_index_sql_whitespace_desc(self):
+        """Test that CREATE INDEX has proper whitespace before DESC."""
+        editor = connection.schema_editor()
+        index = Index(fields=['-headline'], name='test_idx_desc')
+        sql = str(index.create_sql(Article, editor))
+        # Should have space before DESC, not "headline"DESC
+        self.assertIn('"headline" DESC', sql)
+        self.assertNotIn('"headline"DESC', sql)
+
 
 @skipIf(connection.vendor == 'postgresql', 'opclasses are PostgreSQL only')
 class SchemaIndexesNotPostgreSQLTests(TransactionTestCase):
@@ -223,6 +232,32 @@ class SchemaIndexesPostgreSQLTests(TransactionTestCase):
             cursor.execute(self.get_opclass_query % indexname)
             self.assertCountEqual(cursor.fetchall(), [('text_pattern_ops', indexname)])
 
+    def test_ops_class_whitespace(self):
+        """Test proper whitespace in CREATE INDEX with opclasses."""
+        # Test ascending order (empty suffix) doesn't add trailing space
+        index_asc = Index(
+            name='test_ops_class_asc',
+            fields=['body'],
+            opclasses=['text_pattern_ops'],
+        )
+        with connection.schema_editor() as editor:
+            sql = str(index_asc.create_sql(IndexedArticle2, editor))
+            # Should not have trailing space after opclass
+            self.assertNotIn('text_pattern_ops )', sql)
+            self.assertIn('text_pattern_ops)', sql)
+
+        # Test descending order has proper spacing
+        index_desc = Index(
+            name='test_ops_class_desc',
+            fields=['-body'],
+            opclasses=['text_pattern_ops'],
+        )
+        with connection.schema_editor() as editor:
+            sql = str(index_desc.create_sql(IndexedArticle2, editor))
+            # Should have space before DESC, no double spaces
+            self.assertIn('text_pattern_ops DESC', sql)
+            self.assertNotIn('text_pattern_ops  DESC', sql)
+
 
 @skipUnless(connection.vendor == 'mysql', 'MySQL tests')
 class SchemaIndexesMySQLTests(TransactionTestCase):