It was deprecated from Starlette, but if you have code that used it, you can easily **migrate** to <a href="https://github.com/ciscorn/starlette-graphene3" class="external-link" target="_blank">starlette-graphene3</a>, that covers the same use case and has an **almost identical interface**.

!!! tip

    Keep in mind that dataclasses can't do everything Pydantic models can do.

    So, you might still need to use Pydantic models.

    But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

## Dataclasses in `response_model`

You can also use `dataclasses` in the `response_model` parameter:

```Python hl_lines="1  7-13  19"
{!../../../docs_src/dataclasses/tutorial002.py!}

                        "content": {
                            "application/json": {



...
```

#### What is OpenAPI for

The OpenAPI schema is what powers the two interactive documentation systems included.

And there are dozens of alternatives, all based on OpenAPI. You could easily add any of those alternatives to your application built with **FastAPI**.

又例如，一个对象`orion_cat`（`Pet`的一个实例）可以有一个属性`orion_cat.type`, 对标数据库中的`type`列。并且该属性的值可以是其它，例如`"cat"`。

这些 ORM 还具有在表或实体之间建立关系的工具（比如创建多表关系）。

这样，您还可以拥有一个属性`orion_cat.owner`，它包含该宠物所有者的数据，这些数据取自另外一个表。

因此，`orion_cat.owner.name`可能是该宠物主人的姓名（来自表`owners`中的列`name`）。

它可能有一个像`"Arquilian"`(一种业务逻辑)。

当您尝试从您的宠物对象访问它时，ORM 将完成所有工作以从相应的表*所有者那里再获取信息。*

常见的 ORM 例如：Django-ORM（Django 框架的一部分）、SQLAlchemy ORM（SQLAlchemy 的一部分，独立于框架）和 Peewee（独立于框架）等。

* 🌐 Add French translation for FastAPI People. PR [#2232](https://github.com/tiangolo/fastapi/pull/2232) by [@JulianMaurin](https://github.com/JulianMaurin).
* 🌐 Add Korean translation for Tutorial - Path Parameters. PR [#2355](https://github.com/tiangolo/fastapi/pull/2355) by [@hard-coders](https://github.com/hard-coders).

## Top Translation Reviewers

These users are the **Top Translation Reviewers**. 🕵️

I only speak a few languages (and not very well 😅). So, the reviewers are the ones that have the [**power to approve translations**](contributing.md#translations){.internal-link target=_blank} of the documentation. Without them, there wouldn't be documentation in several other languages.

{% if people %}

If you are paying for 3 servers but you are using only a little bit of their RAM and CPU, you are probably **wasting money** 💸, and probably **wasting server electric power** 🌎, etc.

In that case, it could be better to have only 2 servers and use a higher percentage of their resources (CPU, memory, disk, network bandwidth, etc).

By declaring types for your variables, editors and tools can give you better support.

This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

👫 🐜 ✔️ 🧰 ⚒ 🔗 ⚖️ 🔗 🖖 🏓 ⚖️ 👨‍💼.

👉 🌌, 👆 💪 ✔️ 🔢 `orion_cat.owner` & 👨‍💼 🔜 🔌 💽 👉 🐶 👨‍💼, ✊ ⚪️➡️ 🏓 *👨‍💼*.

, `orion_cat.owner.name` 💪 📛 (⚪️➡️ `name` 🏓 `owners` 🏓) 👉 🐶 👨‍💼.

⚫️ 💪 ✔️ 💲 💖 `"Arquilian"`.

& 🐜 🔜 🌐 👷 🤚 ℹ ⚪️➡️ 🔗 🏓 *👨‍💼* 🕐❔ 👆 🔄 🔐 ⚫️ ⚪️➡️ 👆 🐶 🎚.

⚠ 🐜 🖼: ✳-🐜 (🍕 ✳ 🛠️), 🇸🇲 🐜 (🍕 🇸🇲, 🔬 🛠️) & 🏒 (🔬 🛠️), 👪 🎏.

By the last <a href="https://www.jetbrains.com/research/python-developers-survey-2018/#development-tools" class="external-link" target="_blank">Python Developer Survey</a>, that covers about 80% of the users.