```Python
from typing import List, Dict
from datetime import date

from pydantic import BaseModel

# Deklarieren Sie eine Variable als ein `str`
# und bekommen Sie Editor-Unterstütung innerhalb der Funktion
def main(user_id: str):
    return user_id


# Ein Pydantic-Modell
class User(BaseModel):
    id: int
    name: str
    joined: date
```

Das kann nun wie folgt verwendet werden:

```Python

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note
    Polecenie `uvicorn main:app` odnosi się do:

    * `main`: plik `main.py` ("moduł" Python).
    * `app`: obiekt utworzony w pliku `main.py` w lini `app = FastAPI()`.
    * `--reload`: sprawia, że serwer uruchamia się ponownie po zmianie kodu. Używany tylko w trakcie tworzenia oprogramowania.

## Main **FastAPI** app

And now in the file `sql_app/main.py` let's integrate and use all the other parts we created before.

### Create the database tables

In a very simplistic way create the database tables:

```Python hl_lines="9-11"
{!../../../docs_src/sql_databases_peewee/sql_app/main.py!}
```

### Create a dependency

INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary>Nipa aṣẹ kóòdù náà <code>uvicorn main:app --reload</code>...</summary>

Àṣẹ `uvicorn main:app` ń tọ́ka sí:

* `main`: fáìlì náà 'main.py' (Python "module").
* `app` jẹ object( i.e. nǹkan) tí a ṣẹ̀dá nínú `main.py` pẹ̀lú ilà `app = FastAPI()`.

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note
    Câu lệnh `uvicorn main:app` được giải thích như sau:

    * `main`: tệp tin `main.py` (một Python "mô đun").
    * `app`: một object được tạo ra bên trong `main.py` với dòng `app = FastAPI()`.
    * `--reload`: làm server khởi động lại sau mỗi lần thay đổi. Chỉ sử dụng trong môi trường phát triển.

All this renewal process, while still serving the app, is one of the main reasons why you would want to have a **separate system to handle HTTPS** with a TLS Termination Proxy instead of just using the TLS certificates with the application server directly (e.g. Uvicorn).

## Recap

- `main`: `main.py`ファイル (Python "モジュール")
- `app`: `main.py` の`app = FastAPI()`の行で生成されたオブジェクト
- `--reload`: コードを変更したらサーバーを再起動します。このオプションは開発環境でのみ使用します

</details>

### 動作確認

ブラウザから<a href="http://127.0.0.1:8000/items/5?q=somequery" class="external-link" target="_blank">http://127.0.0.1:8000/items/5?q=somequery</a>を開きます。

以下の JSON のレスポンスが確認できます:

```JSON
{"item_id": 5, "q": "somequery"}
```

```Python hl_lines="1  3  7" title="app/main.py"
{!../../../docs_src/bigger_applications/app/main.py!}
```

### 🗄 `APIRouter`

🔜 👥 🗄 🎏 🔁 👈 ✔️ `APIRouter`Ⓜ:

```Python hl_lines="5" title="app/main.py"
{!../../../docs_src/bigger_applications/app/main.py!}
```

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note "Not"
    `uvicorn main:app` komutunu şu şekilde açıklayabiliriz:

    * `main`: dosya olan `main.py` (yani Python "modülü").
    * `app`: ise `main.py` dosyasının içerisinde `app = FastAPI()` satırında oluşturduğumuz `FastAPI` nesnesi.

    `Item(**item.dict(), owner_id=user_id)`

## Main **FastAPI** app

And now in the file `sql_app/main.py` let's integrate and use all the other parts we created before.

### Create the database tables

In a very simplistic way create the database tables:

=== "Python 3.9+"

    ```Python hl_lines="7"
    {!> ../../../docs_src/sql_databases/sql_app_py39/main.py!}
    ```

=== "Python 3.8+"