If you had multiple clients talking to your app exactly at the same time, this is what could happen.

And as your app starts to handle more and more clients at the same time, the waiting time in a single request needs to be shorter and shorter to trigger the error.

### Fix Peewee with FastAPI

Now go back to the file `sql_app/database.py`, and uncomment the line:

```Python

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [2248755] using WatchFiles
INFO:     Started server process [2248757]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>About the command <code>fastapi dev main.py</code>...</summary>

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>🔃 📋 <code>uvicorn main:app --reload</code>...</summary>

📋 `uvicorn main:app` 🔗:

    await do_stuff()
```

When you create a context manager or an async context manager like above, what it does is that, before entering the `with` block, it will execute the code before the `yield`, and after exiting the `with` block, it will execute the code after the `yield`.

In our code example above, we don't use it directly, but we pass it to FastAPI for it to use it.

This was designed this way mainly to allow using the same objects "yielded" by dependencies inside of background tasks, because the exit code would be executed after the background tasks were finished.

Nevertheless, as this would mean waiting for the response to travel through the network while unnecessarily holding a resource in a dependency with yield (for example a database connection), this was changed in FastAPI 0.106.0.

!!! tip

<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

Il est **FORTEMENT encouragé** que vous écriviez ou copiez le code, l'éditiez et l'exécutiez localement.

## Writing templates

Then you can write a template at `templates/item.html` with, for example:

```jinja hl_lines="7"
{!../../../docs_src/templates/templates/item.html!}
```

### Template Context Values

<img src="/img/tutorial/dependencies/image02.png">

## Shortcut

But you see that we are having some code repetition here, writing `CommonQueryParams` twice:

=== "Python 3.8+"

    ```Python
    commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip

## 使用 CLI 登录

现在，使用 CLI 登录 Deta：

<div class="termy">

```console
$ deta login

Please, log in from the web page. Waiting..
Logged in successfully.
```

</div>

这个命令会打开浏览器并自动验证身份。

## 使用 Deta 部署

接下来，使用 Deta CLI 部署应用：

<div class="termy">

```console
$ deta new