Gunicorn would also take care of managing **dead processes** and **restarting** new ones if needed to keep the number of workers. So that helps in part with the **restart** concept from the list above.

Nevertheless, you would probably also want to have something outside making sure to **restart Gunicorn** if necessary, and also to **run it on startup**, etc.

## Uvicorn with Workers

## Use `SecurityScopes`

Now update the dependency `get_current_user`.

This is the one used by the dependencies above.

Here's were we are using the same OAuth2 scheme we created before, declaring it as a dependency: `oauth2_scheme`.

That also applies to callables with no parameters at all. The same as it would be for *path operation functions* with no parameters.

Then, we can change the dependency "dependable" `common_parameters` from above to the class `CommonQueryParams`:

=== "Python 3.10+"

    ```Python hl_lines="11-15"
    {!> ../../../docs_src/dependencies/tutorial002_an_py310.py!}
    ```

=== "Python 3.9+"

    ```

The same as when declaring query parameters, when a model attribute has a default value, it is not required. Otherwise, it is required. Use `None` to make it just optional.

For example, this model above declares a JSON "`object`" (or Python `dict`) like:

```JSON
{
    "name": "Foo",
    "description": "An optional description",
    "price": 45.2,
    "tax": 3.5
}
```

```bash
pip install fastapi
```

...it includes the same code and dependencies as:

```bash
pip install "fastapi-slim[standard]"
```

The standard extra dependencies are the ones mentioned above.

## License

    But Pydantic also uses the term "**model**" to refer to something different, the data validation, conversion, and documentation classes and instances.

Import `Base` from `database` (the file `database.py` from above).

Create classes that inherit from it.

These classes are the SQLAlchemy models.

```Python hl_lines="4  7-8  18-19"
{!../../../docs_src/sql_databases/sql_app/models.py!}
```

```bash
pip install fastapi
```

...it includes the same code and dependencies as:

```bash
pip install "fastapi-slim[standard]"
```

The standard extra dependencies are the ones mentioned above.

## License

    if dependant.body_params:
        (
            body_values,
            body_errors,
        ) = await request_body_to_args(  # body_params checked above
            required_params=dependant.body_params, received_body=body
        )
        values.update(body_values)
        errors.extend(body_errors)
    if dependant.http_connection_param_name: