In this case, we pass a dependency function `get_current_active_user` to `Security` (the same way we would do with `Depends`).

But we also pass a `list` of scopes, in this case with just one scope: `items` (it could have more).

If you are starting a project from scratch, you are probably better off with SQLAlchemy ORM ([SQL (Relational) Databases](../tutorial/sql-databases.md){.internal-link target=_blank}), or any other async ORM.

If you already have a code base that uses <a href="https://docs.peewee-orm.com/en/latest/" class="external-link" target="_blank">Peewee ORM</a>, you can check here how to use it with **FastAPI**.

!!! warning "Python 3.7+ required"

In this case, if you had **multiple containers**, by default, when Prometheus came to **read the metrics**, it would get the ones for **a single container each time** (for the container that handled that particular request), instead of getting the **accumulated metrics** for all the replicated containers.

```

### ✍ `Base` 🎓

🔜 👥 🔜 ⚙️ 🔢 `declarative_base()` 👈 📨 🎓.

⏪ 👥 🔜 😖 ⚪️➡️ 👉 🎓 ✍ 🔠 💽 🏷 ⚖️ 🎓 (🐜 🏷):

```Python hl_lines="13"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

## ✍ 💽 🏷

➡️ 🔜 👀 📁 `sql_app/models.py`.

### ✍ 🇸🇲 🏷 ⚪️➡️ `Base` 🎓

👥 🔜 ⚙️ 👉 `Base` 🎓 👥 ✍ ⏭ ✍ 🇸🇲 🏷.

!!! tip

!!! info "技術詳細"
    **FastAPI**は、`OAuth2PasswordBearer` クラス (依存関係で宣言されている) を使用してOpenAPIのセキュリティスキームを定義できることを知っています。これは`fastapi.security.oauth2.OAuth2`、`fastapi.security.base.SecurityBase`を継承しているからです。

    OpenAPIと統合するセキュリティユーティリティ (および自動APIドキュメント) はすべて`SecurityBase`を継承しています。それにより、**FastAPI**はそれらをOpenAPIに統合する方法を知ることができます。

## どのように動作するか

```

#### Raspberry Pi e outras arquiteturas

Se você estiver rodando Docker em um Raspberry Pi (que possui um processador ARM) ou qualquer outra arquitetura, você pode criar um `Dockerfile` do zero, baseado em uma imagem base Python (que é multi-arquitetural) e utilizar Uvicorn sozinho.

Nesse caso, seu `Dockerfile` poderia parecer assim:

```Dockerfile
FROM python:3.7

RUN pip install fastapi uvicorn

EXPOSE 80

!!! tip
    If you want something quick to copy and paste, don't use this example, use the last one below.

Then, when you create an instance of that `Settings` class (in this case, in the `settings` object), Pydantic will read the environment variables in a case-insensitive way, so, an upper-case variable `APP_NAME` will still be read for the attribute `app_name`.

For example:

```Python
class Cat:
    def __init__(self, name: str):
        self.name = name


fluffy = Cat(name="Mr Fluffy")
```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

    * As the `q` parameter is declared with `= None`, it is optional.
    * Without the `None` it would be required (as is the body in the case with `PUT`).
* For `PUT` requests to `/items/{item_id}`, Read the body as JSON:
    * Check that it has a required attribute `name` that should be a `str`.

        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="4  12  20"
    {!> ../../../docs_src/dependencies/tutorial008.py!}
    ```

And all of them can use `yield`.

In this case `dependency_c`, to execute its exit code, needs the value from `dependency_b` (here named `dep_b`) to still be available.