```Python hl_lines="9"
    {!> ../../../docs_src/sql_databases/sql_app/main.py!}
    ```

#### Alembic Note

Normally you would probably initialize your database (create tables, etc) with <a href="https://alembic.sqlalchemy.org/en/latest/" class="external-link" target="_blank">Alembic</a>.

And you would also use Alembic for "migrations" (that's its main job).

    ```

#### Alembic 注意

通常你可能会使用 <a href="https://alembic.sqlalchemy.org/en/latest/" class="external-link" target="_blank">Alembic</a>，来进行格式化数据库（创建表等）。

而且您还可以将 Alembic 用于“迁移”（这是它的主要工作）。

“迁移”是每当您更改 SQLAlchemy 模型的结构、添加新属性等以在数据库中复制这些更改、添加新列、新表等时所需的一组步骤。

### ✍ 🔗

🔜 ⚙️ `SessionLocal` 🎓 👥 ✍ `sql_app/database.py` 📁 ✍ 🔗.

👥 💪 ✔️ 🔬 💽 🎉/🔗 (`SessionLocal`) 📍 📨, ⚙️ 🎏 🎉 🔘 🌐 📨 & ⤴️ 🔐 ⚫️ ⏮️ 📨 🏁.

& ⤴️ 🆕 🎉 🔜 ✍ ⏭ 📨.

## Create the tables

In this case, we are creating the tables in the same Python file, but in production, you would probably want to create them with Alembic, integrated with migrations, etc.

Here, this section would run directly, right before starting your **FastAPI** application.

* Create an `engine`.
* Create all the tables from the `metadata` object.

* **SQLAlchemy**-Modelle (unabhängig von Flask-Erweiterungen, sodass sie direkt mit Celery-Workern verwendet werden können).
* Grundlegende Startmodelle für Benutzer (ändern und entfernen Sie nach Bedarf).
* **Alembic**-Migrationen.
* **CORS** (Cross Origin Resource Sharing).
* **Celery**-Worker, welche Modelle und Code aus dem Rest des Backends selektiv importieren und verwenden können.