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Using the init plugin
---------------------
In our example application, we've seen that we need to manage the database engine within the scope of the application's
lifespan, and the session within the scope of a request. This is a common pattern, and the
:class:`SQLAlchemyInitPlugin <litestar.contrib.sqlalchemy.plugins.SQLAlchemyInitPlugin>` plugin provides assistance for
this.
In our latest update, we leverage two features of the plugin:
1. The plugin will automatically create a database engine for us and manage it within the scope of the application's
lifespan.
2. The plugin will automatically create a database session for us and manage it within the scope of a request.
We access the database session via dependency injection, using the ``db_session`` parameter.
Here's the updated code:
.. literalinclude:: /examples/contrib/sqlalchemy/plugins/tutorial/full_app_with_init_plugin.py
:language: python
:linenos:
:emphasize-lines: 12, 28, 76-78, 85
The most notable difference is that we no longer need the ``db_connection()`` lifespan context manager - the plugin
handles this for us. It also handles the creation of the tables in our database if we supply our metadata and
set ``create_all=True`` when creating a ``SQLAlchemyAsyncConfig`` instance.
Additionally, we have a new ``db_session`` dependency available to us, which we use in our ``provide_transaction()``
dependency provider, instead of creating our own session.
Next steps
==========
Next up, we'll make one final change to our application, and then we'll be recap!
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