raise exception when deletes is called with a subquery and add the skipped test.

Author: WaVEV

django_mongodb/features.py

@@ -92,8 +92,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         "schema.tests.SchemaTests.test_composed_constraint_with_fk",
         "schema.tests.SchemaTests.test_remove_ignored_unique_constraint_not_create_fk_index",
         "schema.tests.SchemaTests.test_unique_constraint",
-        # Delete does not support subqueries.
-        "delete_regress.tests.DeleteTests.test_self_reference_with_through_m2m_at_second_level",
         # Handle column default value.
         # https://github.com/mongodb-labs/django-mongodb/issues/155
         "annotations.tests.NonAggregateAnnotationTestCase.test_empty_queryset_annotation",
@@ -396,6 +394,9 @@ def django_test_expected_failures(self):
             "schema.tests.SchemaTests.test_rename_column_renames_deferred_sql_references",
             "schema.tests.SchemaTests.test_rename_table_renames_deferred_sql_references",
         },
+        "Subqueries cannot be used in delete operations": {
+            "delete_regress.tests.DeleteTests.test_self_reference_with_through_m2m_at_second_level"
+        },
         "Test executes raw SQL.": {
             "aggregation.tests.AggregateTestCase.test_coalesced_empty_result_set",
             "aggregation_regress.tests.AggregationTests.test_annotate_with_extra",

django_mongodb/query.py

@@ -65,6 +65,8 @@ def __repr__(self):
     @wrap_database_errors
     def delete(self):
         """Execute a delete query."""
+        if self.compiler.subqueries:
+            raise NotSupportedError("Subqueries are not supported in delete operations.")
         return self.collection.delete_many(self.mongo_query).deleted_count
 
     @wrap_database_errors