# Using Dataclasses

FastAPI is built on top of **Pydantic**, and I have been showing you how to use Pydantic models to declare requests and responses.

But FastAPI also supports using <a href="https://docs.python.org/3/library/dataclasses.html" class="external-link" target="_blank">`dataclasses`</a> the same way:

```Python hl_lines="1  7-12  19-20"
{!../../../docs_src/dataclasses/tutorial001.py!}
```

```

!!! tip
    You could reduce duplication in that code by putting it in a function and using it from both `database.py` and `tests/test_sql_app.py`.

    For simplicity and to focus on the specific testing code, we are just copying it.

## Create the database

Because now we are going to use a new database in a new file, we need to make sure we create the database with:

```Python
Base.metadata.create_all(bind=engine)
```

```console
// Use the command "build-all", this will take a bit
$ python ./scripts/docs.py build-all

Updating es
Updating en
Building docs for: en
Building docs for: es
Successfully built docs for: es
Copying en index.md to README.md
```

</div>

👈 🏗 🌐 🩺 `./docs_build/` 🔠 🇪🇸. 👉 🔌 ❎ 🙆 📁 ⏮️ ❌ ✍, ⏮️ 🗒 💬 👈 "👉 📁 🚫 ✔️ ✍". ✋️ 👆 🚫 ✔️ 🕳 ⏮️ 👈 📁.

```console
// Use o comando "build-all", isso leverá um tempinho
$ python ./scripts/docs.py build-all

Updating es
Updating en
Building docs for: en
Building docs for: es
Successfully built docs for: es
Copying en index.md to README.md
```

</div>

* `deprecated`: to mark all the *path operations* in a router as deprecated in OpenAPI.
* `include_in_schema`: to allow disabling all the *path operations* from showing in the OpenAPI schema.
* `callbacks`: OpenAPI callbacks that apply to all the *path operations* in this router.

```console
// Use the command "build-all", this will take a bit
$ python ./scripts/docs.py build-all

Updating es
Updating en
Building docs for: en
Building docs for: es
Successfully built docs for: es
Copying en index.md to README.md
```

</div>

This is in contrast to the **development** stages, where you are constantly changing the code, breaking it and fixing it, stopping and restarting the development server, etc.

## Deployment Strategies

There are several ways to do it depending on your specific use case and the tools that you use.

!!! tip
    The `shutdown` would happen when you are **stopping** the application.

    Maybe you need to start a new version, or you just got tired of running it. 🤷

### Lifespan function

When you do this, the examples will be part of the internal **JSON Schema** for that body data.

Nevertheless, at the <abbr title="2023-08-26">time of writing this</abbr>, Swagger UI, the tool in charge of showing the docs UI, doesn't support showing multiple examples for the data in **JSON Schema**. But read below for a workaround.

### OpenAPI-specific `examples`

```console
// 「build-all」コマンドは少し時間がかかります。
$ python ./scripts/docs.py build-all

Updating es
Updating en
Building docs for: en
Building docs for: es
Successfully built docs for: es
Copying en index.md to README.md
```

</div>

これで、言語ごとにすべてのドキュメントが`./docs_build/`に作成されます。

これには、翻訳が欠落しているファイルを追加することと、「このファイルにはまだ翻訳がない」というメモが含まれます。ただし、そのディレクトリで何もする必要はありません。