### `response_model` Priority

If you declare both a return type and a `response_model`, the `response_model` will take priority and be used by FastAPI.

### Приоритет `response_model`

Если одновременно указать аннотацию типа для ответа функции и параметр `response_model` - последний будет иметь больший приоритет и FastAPI будет использовать именно его.

    {!> ../../../docs_src/response_model/tutorial001_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="17  22  24-27"
    {!> ../../../docs_src/response_model/tutorial001.py!}
    ```

!!! note "Hinweis"
    Beachten Sie, dass `response_model` ein Parameter der „Dekorator“-Methode ist (`get`, `post`, usw.). Nicht der *Pfadoperation-Funktion*, so wie die anderen Parameter.

    👉 ✔ `response_model_by_alias` 👈 👷 ➡.

=== "🐍 3️⃣.6️⃣ & 🔛"

    ```Python hl_lines="31  37"
    {!> ../../../docs_src/response_model/tutorial005.py!}
    ```

=== "🐍 3️⃣.1️⃣0️⃣ & 🔛"

    ```Python hl_lines="29  35"
    {!> ../../../docs_src/response_model/tutorial005_py310.py!}
    ```

!!! tip

* Tự động tài liệu hóa data model theo <a href="https://json-schema.org/" class="external-link" target="_blank"><strong>JSON Schema</strong></a> (OpenAPI bản thân nó được dựa trên JSON Schema).

```Python hl_lines="17"
{!../../../docs_src/path_params/tutorial005.py!}
```

#### Получение *значения перечисления*

Можно получить фактическое значение (в данном случае - `str`) с помощью `model_name.value` или в общем случае `your_enum_member.value`:

```Python hl_lines="20"
{!../../../docs_src/path_params/tutorial005.py!}
```

!!! tip "Подсказка"

```Python hl_lines="17"
{!../../../docs_src/path_params/tutorial005.py!}
```

#### Récupérer la *valeur de l'énumération*

Vous pouvez obtenir la valeur réel d'un membre (une chaîne de caractères ici), avec `model_name.value`, ou en général, `votre_membre_d'enum.value` :

```Python hl_lines="20"
{!../../../docs_src/path_params/tutorial005.py!}
```

!!! tip "Astuce"

!!! 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.

这样，而不是仅仅试图从`dict`上 `id` 中获取值，如下所示：

```Python
id = data["id"]
```

尝试从属性中获取它，如：

```Python
id = data.id
```

有了这个，Pydantic*模型*与 ORM 兼容，您只需在*路径操作*`response_model`的参数中声明它即可。

您将能够返回一个数据库模型，它将从中读取数据。

#### ORM 模式的技术细节

SQLAlchemy 和许多其他默认情况下是“延迟加载”。

这意味着，例如，除非您尝试访问包含该数据的属性，否则它们不会从数据库中获取关系数据。

例如，访问属性`items`：

```Python
current_user.items

Many packages that simplify it a lot have to make many compromises with the data model, database, and available features. And some of these packages that simplify things too much actually have security flaws underneath.

---

**FastAPI** doesn't make any compromise with any database, data model or tool.

It gives you all the flexibility to choose the ones that fit your project the best.