AddField support

django_mongodb/schema.py

@@ -92,6 +92,12 @@ def add_field(self, model, field):
             self.get_collection(model._meta.db_table).update_many(
                 {}, [{"$set": {column: self.effective_default(field)}}]
             )
+        if isinstance(field, EmbeddedModelField):
+            new_path = f"{field.column}."
+            self._create_model_indexes(
+                field.embedded_model, parent_model=model, column_prefix=new_path
+            )
+
         # Add an index or unique, if required.
         if self._field_should_be_indexed(model, field):
             self._add_field_index(model, field)

tests/schema_/test_embedded_model.py

@@ -163,7 +163,7 @@ def assertTableExists(self, model):
     def assertTableNotExists(self, model):
         self.assertNotIn(model._meta.db_table, connection.introspection.table_names())
 
-    # Tests
+    # SchemaEditor.create_model() tests
     def test_db_index(self):
         """Field(db_index=True) on an embedded model."""
         with connection.schema_editor() as editor:
@@ -391,3 +391,33 @@ class Meta:
             )
             editor.delete_model(Author)
         self.assertTableNotExists(Author)
+
+    # SchemaEditor.add_field() tests
+    @isolate_apps("schema_")
+    def test_add_field_db_index(self):
+        """AddField + EmbeddedModelField"""
+
+        class Book(models.Model):
+            name = models.CharField(max_length=100)
+
+            class Meta:
+                app_label = "schema_"
+
+        new_field = EmbeddedModelField(Author)
+        new_field.set_attributes_from_name("author")
+
+        with connection.schema_editor() as editor:
+            # Create the table amd add the field.
+            editor.create_model(Book)
+            editor.add_field(Book, new_field)
+            # Embedded indexes are created.
+            self.assertEqual(
+                self.get_constraints_for_columns(Book, ["author.age"]),
+                ["schema__book_author.age_dc08100b"],
+            )
+            self.assertEqual(
+                self.get_constraints_for_columns(Book, ["author.address.zip_code"]),
+                ["schema__book_author.address.zip_code_7b9a9307"],
+            )
+            editor.delete_model(Book)
+        self.assertTableNotExists(Author)