///

This is a very simple and short tutorial, if you want to learn about databases in general, about SQL, or more advanced features, go to the [SQLModel docs](https://sqlmodel.tiangolo.com/).

## Install `SQLModel` { #install-sqlmodel }

The benefit of raising an exception over returning a value will be more evident in the section about Dependencies and Security.

In this example, when the client requests an item by an ID that doesn't exist, raise an exception with a status code of `404`:

{* ../../docs_src/handling_errors/tutorial001_py310.py hl[11] *}

3. **Actively collaborate with us.** We commit real time and attention to everything we review. Low-effort submissions—where code is generated,...

你可以在編輯器中連接偵錯器，例如 Visual Studio Code 或 PyCharm。

## 呼叫 `uvicorn` { #call-uvicorn }

在你的 FastAPI 應用程式中，直接匯入並執行 `uvicorn`：

{* ../../docs_src/debugging/tutorial001_py310.py hl[1,15] *}

### 關於 `__name__ == "__main__"` { #about-name-main }

`__name__ == "__main__"` 的主要目的是，當你的檔案以以下方式呼叫時，執行某些程式碼：

<div class="termy">

```console
$ python myapp.py
```

</div>

但當其他檔案匯入它時不會執行，例如：

```Python
from myapp import app

* 在 [**Dev.to**](https://dev.to/tiangolo) 或 [**Medium**](https://medium.com/@tiangolo) 閱讀我寫的內容（或關注我）。
    * 閱讀我的想法、文章，以及我建立的工具。
    * 關注我以便在我發佈新內容時能第一時間看到。

## 在 X（Twitter）發文談談 **FastAPI** { #tweet-about-fastapi }

[發一則關於 **FastAPI** 的推文](https://x.com/compose/tweet?text=I'm loving @fastapi because... https://github.com/fastapi/fastapi)，讓我與其他人知道你為什麼喜歡它。🎉

我很樂於聽到 **FastAPI** 是如何被使用、你喜歡它的哪些地方、在哪個專案／公司使用它等等。

           *
           * ...when we build with JDK 22 and run under JDK 8.
           */
          || info.getName().contains("MultimapsTest")
      /*
       * Luckily, we don't care about analyzing tests at all. We'd skip them all if we could do so
       * trivially, but it's enough to skip these ones.
       */
      ) {
        continue;
      }
      Class<?> clazz = info.load();
      try {

你可以在编辑器中连接调试器，例如使用 Visual Studio Code 或 PyCharm。

## 调用 `uvicorn` { #call-uvicorn }

在你的 FastAPI 应用中直接导入 `uvicorn` 并运行：

{* ../../docs_src/debugging/tutorial001_py310.py hl[1,15] *}

### 关于 `__name__ == "__main__"` { #about-name-main }

`__name__ == "__main__"` 的主要目的是使用以下代码调用文件时执行一些代码：

<div class="termy">

```console
$ python myapp.py
```

</div>

而当其它文件导入它时并不会被调用，像这样：

```Python
from myapp import app

    /** Constructor */
    protected final Constructor<?> constructor;

    /** Array of constructor parameter types */
    protected final Class<?>[] parameterTypes;

    /** Information about parameterized argument types */
    protected final ParameterizedClassDesc[] parameterizedClassDescs;

    /**
     * Constructs an instance.
     *
     * @param beanDesc

import org.apache.maven.api.Service;
import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Service for detecting and providing information about the operating system (OS)
 * on which the application is running.
 * <p>
 * This service provides a platform-independent way to:
 * <ul>
 * <li>Query basic OS information like name, architecture, and version</li>

It doesn't matter. **FastAPI** will know what to do.

/// note

If you don't know, check the [Async: *"In a hurry?"*](../../async.md#in-a-hurry) section about `async` and `await` in the docs.

///

## Integrated with OpenAPI { #integrated-with-openapi }