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).

* `sql_app/__init__.py`: is an empty file.

* `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`:

pkg database/sql, const LevelDefault = 0
pkg database/sql, const LevelDefault IsolationLevel
pkg database/sql, const LevelLinearizable = 7
pkg database/sql, const LevelLinearizable IsolationLevel
pkg database/sql, const LevelReadCommitted = 2
pkg database/sql, const LevelReadCommitted IsolationLevel
pkg database/sql, const LevelReadUncommitted = 1
pkg database/sql, const LevelReadUncommitted IsolationLevel

`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`:

pkg database/sql, method (*Conn) QueryRowContext(context.Context, string, ...interface{}) *Row
pkg database/sql, method (*DB) Conn(context.Context) (*Conn, error)
pkg database/sql, type Conn struct
pkg database/sql, type Out struct
pkg database/sql, type Out struct, Dest interface{}
pkg database/sql, type Out struct, In bool
pkg database/sql, var ErrConnDone error

     contents in a database in which You have Sui Generis Database
     Rights, then the database in which You have Sui Generis Database
     Rights (but not its individual contents) is Adapted Material; and

  c. You must comply with the conditions in Section 3(a) if You Share
     all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not

---> 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`.

	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"`
}

	Host               xnet.URL `json:"host"`
	Port               string   `json:"port"`
	User               string   `json:"user"`
	Password           string   `json:"password"`
	Database           string   `json:"database"`
	QueueDir           string   `json:"queueDir"`
	QueueLimit         uint64   `json:"queueLimit"`
	MaxOpenConnections int      `json:"maxOpenConnections"`
}

// Validate MySQLArgs fields