## Overriding the defaults

Using the information above, you can use the same utility function to generate the OpenAPI schema and override each part that you need.

For example, let's add <a href="https://github.com/Rebilly/ReDoc/blob/master/docs/redoc-vendor-extensions.md#x-logo" class="external-link" target="_blank">ReDoc's OpenAPI extension to include a custom logo</a>.

### Normal **FastAPI**

Peewee was not designed for async frameworks, or with them in mind.

Peewee has some heavy assumptions about its defaults and about how it should be used.

If you are developing an application with an older non-async framework, and can work with all its defaults, **it can be a great tool**.

* Data validation
* Automatic documentation

## Defaults

As query parameters are not a fixed part of a path, they can be optional and can have default values.

In the example above they have default values of `skip=0` and `limit=10`.

So, going to the URL:

```
http://127.0.0.1:8000/items/
```

would be the same as going to:

@app.get("/items/{item_id}")
def main(
    item_id: int = Path(default=..., gt=0),
    query: str = Query(default=..., max_length=10),
    session: str = Cookie(default=..., min_length=3),
    x_trace: str = Header(default=..., title="Tracing header"),
):
    return {"message": "Hello World"}
```

...all these parameters are required because the default value is `...` (Ellipsis).

### Short

It has sensible **defaults** for everything, with optional configurations everywhere. All the parameters can be fine-tuned to do what you need and to define the API you need.

But by default, it all **"just works"**.

### Validation

* Validation for most (or all?) Python **data types**, including:

<img src="/img/tutorial/query-params-str-validations/image02.png">

### Query-Parameter-Liste / Mehrere Werte mit Defaults

Und Sie können auch eine Default-`list`e von Werten definieren, wenn keine übergeben werden:

=== "Python 3.9+"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params_str_validations/tutorial012_an_py39.py!}

!!! info "Информация"
    Вы также можете использовать:

    * `response_model_exclude_defaults=True`
    * `response_model_exclude_none=True`

    как описано в <a href="https://docs.pydantic.dev/latest/concepts/serialization/#modeldict" class="external-link" target="_blank">документации Pydantic</a> для параметров `exclude_defaults` и `exclude_none`.

#### Если значение поля отличается от значения по-умолчанию

!!! info "정보"
    아래 또한 사용할 수 있습니다:

    * `response_model_exclude_defaults=True`
    * `response_model_exclude_none=True`

    <a href="https://docs.pydantic.dev/latest/concepts/serialization/#modeldict" class="external-link" target="_blank">Pydantic 문서</a>에서 `exclude_defaults` 및 `exclude_none`에 대해 설명한 대로 사용할 수 있습니다.

#### 기본값이 있는 필드를 갖는 값의 데이터

    ```

👥 ✔️ ❎ 🔢 💲 `None` 🔢 ⏮️ `Query()`, 👥 💪 🔜 ⚒ 🔢 💲 ⏮️ 🔢 `Query(default=None)`, ⚫️ 🍦 🎏 🎯 ⚖ 👈 🔢 💲.

:

```Python
q: Union[str, None] = Query(default=None)
```

...⚒ 🔢 📦, 🎏:

```Python
q: Union[str, None] = None
```

& 🐍 3️⃣.1️⃣0️⃣ & 🔛:

```Python
q: str | None = Query(default=None)
```

...⚒ 🔢 📦, 🎏:

```Python
q: str | None = None
```

Comme nous devons remplacer la valeur par défaut `None` dans la fonction par `Query()`, nous pouvons maintenant définir la valeur par défaut avec le paramètre `Query(default=None)`, il sert le même objectif qui est de définir cette valeur par défaut.

Donc :

```Python
q: Union[str, None] = Query(default=None)
```

... rend le paramètre optionnel, et est donc équivalent à :

```Python
q: Union[str, None] = None
```