Let's refer to the file `sql_app/database.py`.

### Import the SQLAlchemy parts

```Python hl_lines="1-3"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

### Create a database URL for SQLAlchemy

```Python hl_lines="5-6"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

In this example, we are "connecting" to a SQLite database (opening a file with the SQLite database).

{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip
    Notice that all this code is pure SQLAlchemy Core.

    `databases` is not doing anything here yet.

## Import and set up `databases`

* Import `databases`.
* Create a `DATABASE_URL`.
* Create a `database` object.

```Python hl_lines="3  9  12"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip

`sql_app` 🔜 ✔️ 📄 📁:

* `sql_app/__init__.py`: 🛁 📁.

* `sql_app/database.py`:

```Python
{!../../../docs_src/sql_databases_peewee/sql_app/database.py!}
```

* `sql_app/models.py`:

```Python
{!../../../docs_src/sql_databases_peewee/sql_app/models.py!}
```

* `sql_app/schemas.py`:

```Python
{!../../../docs_src/sql_databases_peewee/sql_app/schemas.py!}
```

* `sql_app/crud.py`:

* 创建 `DATABASE_URL`
* 创建 `database`

```Python hl_lines="3  9  12"
{!../../../docs_src/async_sql_databases/tutorial001.py!}
```

!!! tip "提示"

    连接 PostgreSQL 等数据库时，需要修改 `DATABASE_URL`。

## 创建表

本例中，使用 Python 文件创建表，但在生产环境中，应使用集成迁移等功能的 Alembic 创建表。

本例在启动 **FastAPI** 应用前，直接执行这些操作。

* 创建 `engine`
* 使用 `metadata` 对象创建所有表

```Python hl_lines="25-28"

initial_fake_database = {"rick": "Rick Sanchez"}

fake_database = initial_fake_database.copy()

initial_state = {"except": False, "finally": False}

state = initial_state.copy()

app = FastAPI()


async def get_database():
    temp_database = fake_database.copy()
    try:
        yield temp_database
        fake_database.update(temp_database)
    except HTTPException:

---> 100%
```

</div>

## 创建 SQLAlchemy 部件

让我们转到文件`sql_app/database.py`。

### 导入 SQLAlchemy 部件

```Python hl_lines="1-3"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

### 为 SQLAlchemy 定义数据库 URL地址

```Python hl_lines="5-6"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

在这个例子中，我们正在“连接”到一个 SQLite 数据库（用 SQLite 数据库打开一个文件）。

$ pip install sqlalchemy

---> 100%
```

</div>

## ✍ 🇸🇲 🍕

➡️ 🔗 📁 `sql_app/database.py`.

### 🗄 🇸🇲 🍕

```Python hl_lines="1-3"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

### ✍ 💽 📛 🇸🇲

```Python hl_lines="5-6"
{!../../../docs_src/sql_databases/sql_app/database.py!}
```

👉 🖼, 👥 "🔗" 🗄 💽 (📂 📁 ⏮️ 🗄 💽).

📁 🔜 🔎 🎏 📁 📁 `sql_app.db`.

    - 🧰 [SQLModel](https://sqlmodel.tiangolo.com) for the Python SQL database interactions (ORM).
    - 🔍 [Pydantic](https://docs.pydantic.dev), used by FastAPI, for the data validation and settings management.
    - 💾 [PostgreSQL](https://www.postgresql.org) as the SQL database.
- 🚀 [React](https://react.dev) for the frontend.

	Username           string    `json:"username"` // default: user running minio
	Password           string    `json:"password"` // default: no password
	Database           string    `json:"database"` // default: same as user
	QueueDir           string    `json:"queueDir"`
	QueueLimit         uint64    `json:"queueLimit"`
	MaxOpenConnections int       `json:"maxOpenConnections"`
}

                    "operationId": "read_items_items__get",
                    "parameters": [
                        {
                            "description": "Query string for the items to search in the database that have a good match",
                            "required": False,
                            "deprecated": True,
                            "schema": IsDict(
                                {