.. _djangopatchmutation:

================================
DjangoPatchMutation
================================

Will update an existing instance of a model. The PatchMutation (in
contrast to the UpdateMutation) does not require all fields to be
supplied. I.e. all are fields are optional.

Mutation input arguments:

+------------+-----------+
| Argument   | Type      |
+============+===========+
| id         | ID!       |
+------------+-----------+
| input      | Object!   |
+------------+-----------+

All meta arguments:

+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Argument                 | type       | Default   | Description                                                                                                                                                                       |
+==========================+============+===========+===================================================================================================================================================================================+
| model                    | Model      | None      | The model. **Required**.                                                                                                                                                          |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| only\_fields             | Iterable   | None      | If supplied, only these fields will be added as input variables for the model                                                                                                     |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| exclude\_fields          | Iterable   | None      | If supplied, these fields will be excluded as input variables for the model.                                                                                                      |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| return\_field\_name      | String     | None      | The name of the return field within the mutation. The default is the camelCased name of the model                                                                                 |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| permissions              | Tuple      | None      | The permissions required to access the mutation                                                                                                                                   |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| login\_required          | Boolean    | None      | If true, the calling user has to be authenticated                                                                                                                                 |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| auto\_context\_fields    | Dict       | None      | A mapping of context values into model fields. See below                                                                                                                          |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| optional\_fields         | Tuple      | ()        | A list of fields which explicitly should have ``required=False``                                                                                                                  |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| required\_fields         | Tuple      | None      | A list of fields which explicitly should have ``required=True``                                                                                                                   |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| custom\_fields           | Tuple      | None      | A list of custom graphene fields which will be added to the model input type.                                                                                                     |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| type\_name               | String     | None      | If supplied, the input variable in the mutation will have its typename set to this string. This is useful when creating multiple mutations of the same type for a single model.   |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| many\_to\_many\_extras   | Dict       | {}        | A dict with extra information regarding many-to-many fields. See below.                                                                                                           |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| many\_to\_one\_extras    | Dict       | {}        | A dict with extra information regarding many-to-one relations. See below.                                                                                                         |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| foreign\_key\_extras     | Dict       | {}        | A dict with extra information regarding foreign key extras.                                                                                                                       |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| one\_to\_one\_extras     | Dict       | {}        | A dict with extra information regarding one to one extras.                                                                                                                        |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| use_select_for_update    | Boolean    | True      | If true, the queryset will be altered with ``select_for_update``, locking the database rows in question. Used to ensure data integrity on updates.                                |
+--------------------------+------------+-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Example mutation
^^^^^^^^^^^^^^^^

.. code::

    mutation {
        updateUser(id: "VXNlck5vZGU6MQ==", input: {
            name: "John Doe",
        }){
            user{
                id
                name
                address
            }
        }
    }