```Python hl_lines="34"
{!../../../docs_src/body_updates/tutorial002.py!}
```

### 使用 Pydantic 的 `update` 参数

接下来，用 `.copy()` 为已有模型创建调用 `update` 参数的副本，该参数为包含更新数据的 `dict`。

例如，`stored_item_model.copy(update=update_data)`：

```Python hl_lines="35"
{!../../../docs_src/body_updates/tutorial002.py!}
```

### 更新部分数据小结

简而言之，更新部分数据应：

* 使用 `PATCH` 而不是 `PUT` （可选，也可以用 `PUT`）；
* 提取存储的数据；

```

!!! info
    In Pydantic v1 the method was called `.dict()`, it was deprecated (but still supported) in Pydantic v2, and renamed to `.model_dump()`.

    The examples here use `.dict()` for compatibility with Pydantic v1, but you should use `.model_dump()` instead if you can use Pydantic v2.

!!! note

# Extra Models

Continuing with the previous example, it will be common to have more than one related model.

This is especially the case for user models, because:

* The **input model** needs to be able to have a password.
* The **output model** should not have a password.
* The **database model** would probably need to have a hashed password.

!!! danger
    Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

!!! info
    Note that the `TestClient` receives data that can be converted to JSON, not Pydantic models.

    If you have a Pydantic model in your test and you want to send its data to the application during testing, you can use the `jsonable_encoder` described in [JSON Compatible Encoder](encoder.md){.internal-link target=_blank}.

## Run it

## Embed a single body parameter

Let's say you only have a single `item` body parameter from a Pydantic model `Item`.

By default, **FastAPI** will then expect its body directly.

But if you want it to expect a JSON with a key `item` and inside of it the model contents, as it does when you declare extra body parameters, you can use the special `Body` parameter `embed`:

```Python

* Sie sollte wahrscheinlich eine Deklaration des Bodys enthalten, die sie erhalten soll, z. B. `body: InvoiceEvent`.
* Und sie könnte auch eine Deklaration der Response enthalten, die zurückgegeben werden soll, z. B. `response_model=InvoiceEventReceived`.

```Python hl_lines="16-18  21-22  28-32"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

Es gibt zwei Hauptunterschiede zu einer normalen *Pfadoperation*:

⚫️ 🏆 🚫 🎦 🆙 🧾, ✋️ 🎏 🧰 (✅ 🐉) 🔜 💪 ⚙️ 🎂.

```Python hl_lines="19-29"
{!../../../docs_src/path_operation_advanced_configuration/tutorial004.py!}
```

## 🌖 📨

👆 🎲 ✔️ 👀 ❔ 📣 `response_model` & `status_code` *➡ 🛠️*.

👈 🔬 🗃 🔃 👑 📨 *➡ 🛠️*.

👆 💪 📣 🌖 📨 ⏮️ 👫 🏷, 👔 📟, ♒️.

📤 🎂 📃 📥 🧾 🔃 ⚫️, 👆 💪 ✍ ⚫️ [🌖 📨 🗄](additional-responses.md){.internal-link target=_blank}.

## 🗄 ➕

* Fix type declaration of `response_model` to allow generic Python types as `List[Model]`. Mainly to fix `mypy` for users. PR [#266](https://github.com/tiangolo/fastapi/pull/266).

## 0.25.0

* Add support for Pydantic's `include`, `exclude`, `by_alias`.
    * Update documentation: [Response Model](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).

!!! check "Inspired **FastAPI** to"
    Define extra validations for data types using the "default" value of model attributes. This improves editor support, and it was not available in Pydantic before.

The same way, this database wouldn't receive a Pydantic model (an object with attributes), only a `dict`.

You can use `jsonable_encoder` for that.

It receives an object, like a Pydantic model, and returns a JSON compatible version:

=== "Python 3.10+"

    ```Python hl_lines="4  21"
    {!> ../../../docs_src/encoder/tutorial001_py310.py!}