Fixed #30108 -- Allowed adding foreign key constraints in the same statement that adds a field.

2 files changed, 24 insertions, 5 deletions

diff --git a/tests/indexes/tests.py b/tests/indexes/tests.py
index 7eb5dd89a9..ecc449ed4a 100644
--- a/tests/indexes/tests.py
+++ b/tests/indexes/tests.py
@@ -226,11 +226,9 @@ class SchemaIndexesMySQLTests(TransactionTestCase):
                 new_field.set_attributes_from_name('new_foreign_key')
                 editor.add_field(ArticleTranslation, new_field)
                 field_created = True
-                self.assertEqual([str(statement) for statement in editor.deferred_sql], [
-                    'ALTER TABLE `indexes_articletranslation` '
-                    'ADD CONSTRAINT `indexes_articletrans_new_foreign_key_id_d27a9146_fk_indexes_a` '
-                    'FOREIGN KEY (`new_foreign_key_id`) REFERENCES `indexes_article` (`id`)'
-                ])
+                # No deferred SQL. The FK constraint is included in the
+                # statement to add the field.
+                self.assertFalse(editor.deferred_sql)
         finally:
             if field_created:
                 with connection.schema_editor() as editor:
diff --git a/tests/schema/tests.py b/tests/schema/tests.py
index 410a52b646..9b40a43523 100644
--- a/tests/schema/tests.py
+++ b/tests/schema/tests.py
@@ -241,6 +241,27 @@ class SchemaTests(TransactionTestCase):
             editor.alter_field(Book, old_field, new_field, strict=True)
         self.assertForeignKeyExists(Book, 'author_id', 'schema_tag')
 
+    @skipUnlessDBFeature('can_create_inline_fk')
+    def test_inline_fk(self):
+        # Create some tables.
+        with connection.schema_editor() as editor:
+            editor.create_model(Author)
+            editor.create_model(Book)
+            editor.create_model(Note)
+        self.assertForeignKeyNotExists(Note, 'book_id', 'schema_book')
+        # Add a foreign key from one to the other.
+        with connection.schema_editor() as editor:
+            new_field = ForeignKey(Book, CASCADE)
+            new_field.set_attributes_from_name('book')
+            editor.add_field(Note, new_field)
+        self.assertForeignKeyExists(Note, 'book_id', 'schema_book')
+        # Creating a FK field with a constraint uses a single statement without
+        # a deferred ALTER TABLE.
+        self.assertFalse([
+            sql for sql in (str(statement) for statement in editor.deferred_sql)
+            if sql.startswith('ALTER TABLE') and 'ADD CONSTRAINT' in sql
+        ])
+
     @skipUnlessDBFeature('supports_foreign_keys')
     def test_char_field_with_db_index_to_fk(self):
         # Create the table