Mixin Classes
=============

SQLAlchemy supports mixin classes for models to add functionality. OpenAlchemy
supports this through the :samp:`x-mixins` extension property that may define
one or more importable class to mix into the model class.

.. seealso::

    :ref:`mixins`
      OpenAlchemy documentation for the :samp:`x-mixins` value.

The following example adds the :samp:`sqlalchemy_mixins.TimestampsMixin` to
the :samp:`Employee` model:

.. literalinclude:: ../../../examples/mixins/example-spec.yml
    :language: yaml
    :linenos:

The following file uses OpenAlchemy to generate the SQLAlchemy models:

.. literalinclude:: ../../../examples/mixins/models.py
    :language: python
    :linenos:

The SQLAlchemy models generated by OpenAlchemy are equivalent to the following
traditional models file:

.. literalinclude:: ../../../examples/mixins/models_traditional.py
    :language: python
    :linenos:

OpenAlchemy will generate the following typed models:

.. literalinclude:: ../../../examples/mixins/models_auto.py
    :language: python
    :linenos:

.. seealso::
    :ref:`getting-started`