!!! check "检查"

    还是使用 Python 类型声明，**FastAPI** 提供了（集成 Swagger UI 的）API 文档。

    注意，路径参数的类型是整数。

## 基于标准的好处，备选文档

**FastAPI** 使用 <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md" class="external-link" target="_blank">OpenAPI</a> 生成概图，所以能兼容很多工具。

## Bodys mit beliebigen `dict`s

Sie können einen Body auch als `dict` deklarieren, mit Schlüsseln eines Typs und Werten eines anderen Typs.

So brauchen Sie vorher nicht zu wissen, wie die Feld-/Attribut-Namen lauten (wie es bei Pydantic-Modellen der Fall wäre).

Das ist nützlich, wenn Sie Schlüssel empfangen, deren Namen Sie nicht bereits kennen.

---

</p>
<p align="center">
<a href="https://github.com/tiangolo/fastapi/actions?query=workflow%3ATest+event%3Apush+branch%3Amaster" target="_blank">
    <img src="https://github.com/tiangolo/fastapi/workflows/Test/badge.svg?event=push&branch=master" alt="Test">
</a>
<a href="https://codecov.io/gh/tiangolo/fastapi" target="_blank">
    <img src="https://img.shields.io/codecov/c/github/tiangolo/fastapi?color=%2334D058" alt="Coverage">
</a>

</p>
<p align="center">
<a href="https://travis-ci.com/tiangolo/fastapi" target="_blank">
    <img src="https://travis-ci.com/tiangolo/fastapi.svg?branch=master" alt="Build Status">
</a>
<a href="https://codecov.io/gh/tiangolo/fastapi" target="_blank">
    <img src="https://img.shields.io/codecov/c/github/tiangolo/fastapi" alt="Coverage">
</a>

您可以在[Project Generation - Template](https://fastapi.tiangolo.com/zh/project-generation/)的模板中找到一个 FastAPI 项目中的 Alembic 示例。具体在[`alembic`代码目录中](https://github.com/tiangolo/full-stack-fastapi-postgresql/tree/master/src/backend/app/alembic/)。

### 创建依赖项

现在使用我们在`sql_app/database.py`文件中创建的`SessionLocal`来创建依赖项。

我们需要每个请求有一个独立的数据库会话/连接（`SessionLocal`），在所有请求中使用相同的会话，然后在请求完成后关闭它。

然后将为下一个请求创建一个新会话。

def test_router():
    client = TestClient(app)
    with client.websocket_connect("/router") as websocket:
        data = websocket.receive_text()
        assert data == "Hello, router!"


def test_prefix_router():
    client = TestClient(app)
    with client.websocket_connect("/prefix/") as websocket:
        data = websocket.receive_text()
        assert data == "Hello, router with prefix!"


def test_native_prefix_router():

)
router_b_override.include_router(router_b_a, prefix="/a")
router_a.include_router(router_a_a, prefix="/a")
router_a.include_router(
    router_a_b_override, prefix="/b", default_response_class=PlainTextResponse
)
app.include_router(router_a, prefix="/a")
app.include_router(
    router_b_override, prefix="/b", default_response_class=PlainTextResponse
)


client = TestClient(app)

We are importing the submodule `items` directly, instead of importing just its variable `router`.

This is because we also have another variable named `router` in the submodule `users`.

If we had imported one after the other, like:

```Python
from .routers.items import router
from .routers.users import router
```

    if response.status_code != 200:
        logging.error(
            f"Response was not 200, after: {after}, category_id: {category_id}"
        )
        logging.error(response.text)
        raise RuntimeError(response.text)
    data = response.json()
    if "errors" in data:
        logging.error(f"Errors in response, after: {after}, category_id: {category_id}")
        logging.error(data["errors"])

{!../../../docs_src/custom_request_and_route/tutorial002.py!}
```

## Custom `APIRoute` class in a router

You can also set the `route_class` parameter of an `APIRouter`:

```Python hl_lines="26"
{!../../../docs_src/custom_request_and_route/tutorial003.py!}
```