# How To - Recipes

Here you will see different recipes or "how to" guides for **several topics**.

Most of these ideas would be more or less **independent**, and in most cases you should only need to study them if they apply directly to **your project**.

If something seems interesting and useful to your project, go ahead and check it, but otherwise, you might probably just skip them.

!!! tip

* <a href="https://ariadnegraphql.org/" class="external-link" target="_blank">Ariadne</a>
    * With <a href="https://ariadnegraphql.org/docs/starlette-integration" class="external-link" target="_blank">docs for Starlette</a> (that also apply to FastAPI)
* <a href="https://tartiflette.io/" class="external-link" target="_blank">Tartiflette</a>

    ```

And all the ideas in the section about [adding `dependencies` to the *path operation decorators*](dependencies-in-path-operation-decorators.md){.internal-link target=_blank} still apply, but in this case, to all of the *path operations* in the app.

## Dependencies for groups of *path operations*

    This section doesn't apply those ideas, to be equivalent to the counterpart in <a href="https://www.starlette.io/database/" class="external-link" target="_blank">Starlette</a>.

## Import and set up `SQLAlchemy`

* Import `SQLAlchemy`.

In the next chapters, I'll give you more **concrete recipes** to deploy FastAPI applications.

But for now, let's check these important **conceptual ideas**. These concepts also apply to any other type of web API. 💡

## Security - HTTPS

In the [previous chapter about HTTPS](https.md){.internal-link target=_blank} we learned about how HTTPS provides encryption for your API.

## Global Dependencies

* `dependencies`: to include ✨ top-level dependencies ✨ that apply to the whole application. E.g. to add global authentication.
* `callbacks`: OpenAPI callbacks that apply to all the *path operations*.
* `deprecated`: to mark all the *path operations* as deprecated. 🤷
* `include_in_schema`: to allow excluding all the *path operations* from the OpenAPI schema.
* `responses`: OpenAPI responses that apply to all the *path operations*.

For example:

## To `async` or not to `async`

As dependencies will also be called by **FastAPI** (the same as your *path operation functions*), the same rules apply while defining your functions.

You can use `async def` or normal `def`.

    ```

=== "Python 3.8+"

    ```Python hl_lines="35"
    {!> ../../../docs_src/body_updates/tutorial002.py!}
    ```

### Partial updates recap

In summary, to apply partial updates you would:

* (Optionally) use `PATCH` instead of `PUT`.
* Retrieve the stored data.
* Put that data in a Pydantic model.

<img src="/img/tutorial/additional-responses/image01.png">

## Combine predefined responses and custom ones

You might want to have some predefined responses that apply to many *path operations*, but you want to combine them with custom responses needed by each *path operation*.

For those cases, you can use the Python technique of "unpacking" a `dict` with `**dict_to_unpack`:

```Python