```Python
app.dependency_overrides = {}
```

!!! tip

        raise typer.Abort()
    typer.echo("Valid README ✅")


@app.command()
def build_all() -> None:
    """
    Build mkdocs site for en, and then build each language inside, end result is located
    at directory ./site/ with each language inside.
    """
    update_languages()
    shutil.rmtree(site_path, ignore_errors=True)
    langs = [lang.name for lang in get_lang_paths() if lang.is_dir()]

!!! tip "提示"

    为减少代码重复，最好把这段代码写成函数，在 `database.py` 与 `tests/test_sql_app.py`中使用。

    为了把注意力集中在测试代码上，本例只是复制了这段代码。

## 创建数据库

因为现在是想在新文件中使用新数据库，所以要使用以下代码创建数据库：

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

一般是在 `main.py` 中调用这行代码，但在 `main.py` 里，这行代码用于创建 `sql_app.db`，但是现在要为测试创建 `test.db`。

因此，要在测试代码中添加这行代码创建新的数据库文件。

```Python hl_lines="16"
{!../../../docs_src/sql_databases/sql_app/tests/test_sql_app.py!}

```

!!! tip "提示"

    连接 PostgreSQL 等数据库时，需要修改 `DATABASE_URL`。

## 创建表

本例中，使用 Python 文件创建表，但在生产环境中，应使用集成迁移等功能的 Alembic 创建表。

本例在启动 **FastAPI** 应用前，直接执行这些操作。

* 创建 `engine`
* 使用 `metadata` 对象创建所有表

```Python hl_lines="25-28"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

## 创建模型

创建以下 Pydantic 模型：

* 创建笔记的模型（`NoteIn`）
* 返回笔记的模型（`Note`）

    {!> ../../../docs_src/path_operation_configuration/tutorial003_py310.py!}
    ```

## 📛 ⚪️➡️ #️⃣

📛 😑 📏 &amp; 📔 💗 ⏸, 👆 💪 📣 *➡ 🛠️* 📛 🔢 <abbr title="a multi-line string as the first expression inside a function (not assigned to any variable) used for documentation"> #️⃣ </abbr> &amp; **FastAPI** 🔜 ✍ ⚫️ ⚪️➡️ 📤.

* **Taviz yok** hiçbir şeyden taviz vermeden, database frontend vs. Bütün hepsinin kolayca entegre edilebiliyor.

### Sınırsız "plug-inler"

Başka bir deyişle, plug-inlere ihtiyacımız yok, import edip direkt olarak kullanmaya başlayabiliriz.

<img src="/img/tutorial/body/image01.png">

And will be also used in the API docs inside each *path operation* that needs them:

<img src="/img/tutorial/body/image02.png">

## Editor support

In your editor, inside your function you will get type hints and completion everywhere (this wouldn't happen if you received a `dict` instead of a Pydantic model):

    ```Python
    commons: CommonQueryParams = Depends()
    ```

You declare the dependency as the type of the parameter, and you use `Depends()` without any parameter, instead of having to write the full class *again* inside of `Depends(CommonQueryParams)`.

The same example would then look like:

=== "Python 3.10+"

    ```Python hl_lines="19"
    {!> ../../../docs_src/dependencies/tutorial004_an_py310.py!}
    ```

* `Path()`
* `Query()`
* `Header()`
* `Cookie()`
* `Body()`
* `Form()`
* `File()`

you can also declare a group of `examples` with additional information that will be added to their **JSON Schemas** inside of **OpenAPI**.

### `Body` with `examples`

Here we pass `examples` containing one example of the data expected in `Body()`:

=== "Python 3.10+"

    ```Python hl_lines="22-29"

# Additional Status Codes

By default, **FastAPI** will return the responses using a `JSONResponse`, putting the content you return from your *path operation* inside of that `JSONResponse`.

It will use the default status code or the one you set in your *path operation*.

## Additional status codes