made QuerySet.bulk_create() set pk on created model instances

django_mongodb/compiler.py

@@ -677,13 +677,13 @@ def execute_sql(self, returning_fields=None):
 
                 field_values[field.column] = value
             objs.append(field_values)
-        return [self.insert(objs, returning_fields=returning_fields)]
+        return self.insert(objs, returning_fields=returning_fields)
 
     @wrap_database_errors
     def insert(self, docs, returning_fields=None):
         """Store a list of documents using field columns as element names."""
         inserted_ids = self.collection.insert_many(docs).inserted_ids
-        return inserted_ids if returning_fields else []
+        return [(x,) for x in inserted_ids] if returning_fields else []
 
     @cached_property
     def collection_name(self):

django_mongodb/features.py

@@ -10,6 +10,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     allows_multiple_constraints_on_same_fields = False
     can_create_inline_fk = False
     can_introspect_foreign_keys = False
+    can_return_rows_from_bulk_insert = True
     greatest_least_ignores_nulls = True
     has_json_object_function = False
     has_native_json_field = True