!!! tip
    通过创建仅专用于与数据库交互（获取用户或项目）的函数，独立于*路径操作函数*，您可以更轻松地在多个部分中重用它们，并为它们添加单元测试。

### 创建数据

现在创建实用程序函数来创建数据。

它的步骤是：

* 使用您的数据创建一个 SQLAlchemy 模型*实例。*
* 使用`add`来将该实例对象添加到您的数据库。
* 使用`commit`来对数据库的事务提交（以便保存它们）。
* 使用`refresh`来刷新您的数据库实例（以便它包含来自数据库的任何新数据，例如生成的 ID）。

```Python hl_lines="18-24  31-36"
{!../../../docs_src/sql_databases/sql_app/crud.py!}
```

!!! tip

    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    return db_user


def get_items(db: Session, skip: int = 0, limit: int = 100):
    return db.query(models.Item).offset(skip).limit(limit).all()


def create_user_item(db: Session, item: schemas.ItemCreate, user_id: int):
    db_item = models.Item(**item.dict(), owner_id=user_id)
    db.add(db_item)
    db.commit()
    db.refresh(db_item)

      - run: pip install smokeshow

      - uses: dawidd6/action-download-artifact@v3.1.4
        with:
          github_token: ${{ secrets.FASTAPI_SMOKESHOW_DOWNLOAD_ARTIFACTS }}
          workflow: test.yml
          commit: ${{ github.event.workflow_run.head_sha }}

      - run: smokeshow upload coverage-html
        env:
          SMOKESHOW_GITHUB_STATUS_DESCRIPTION: Coverage {coverage-percentage}

* ⬆ [pre-commit.ci] pre-commit autoupdate. PR [#5536](https://github.com/tiangolo/fastapi/pull/5536) by [@pre-commit-ci[bot]](https://github.com/apps/pre-commit-ci).
* 🐛 Fix internal Trio test warnings. PR [#5547](https://github.com/tiangolo/fastapi/pull/5547) by [@samuelcolvin](https://github.com/samuelcolvin).

    # TODO remove pytest-cov
    'ignore::pytest.PytestDeprecationWarning:pytest_cov',
    # TODO: remove after upgrading SQLAlchemy to a version that includes the following changes
    # https://github.com/sqlalchemy/sqlalchemy/commit/59521abcc0676e936b31a523bd968fc157fef0c2
    'ignore:datetime\.datetime\.utcfromtimestamp\(\) is deprecated and scheduled for removal in a future version\..*:DeprecationWarning:sqlalchemy',

### Don't worry about style

* Don't worry too much about things like commit message styles, I will squash and merge customizing the commit manually.

* Also don't worry about style rules, there are already automatized tools checking that.

And if there's any other style or consistency need, I'll ask directly for that, or I'll add commits on top with the needed changes.

### Check the code

### ✍ 💽

🔜 ✍ 🚙 🔢 ✍ 💽.

🔁:

* ✍ 🇸🇲 🏷 *👐* ⏮️ 👆 📊.
* `add` 👈 👐 🎚 👆 💽 🎉.
* `commit` 🔀 💽 (👈 👫 🖊).
* `refresh` 👆 👐 (👈 ⚫️ 🔌 🙆 🆕 📊 ⚪️➡️ 💽, 💖 🏗 🆔).

```Python hl_lines="18-24  31-36"
{!../../../docs_src/sql_databases/sql_app/crud.py!}
```

!!! tip

* Machen Sie sich nicht zu viele Gedanken über Dinge wie den Stil von Commit-Nachrichten, ich werde den Commit manuell zusammenführen und anpassen.

* Machen Sie sich auch keine Sorgen über Stilregeln, es gibt bereits automatisierte Tools, die das überprüfen.

Und wenn es irgendeinen anderen Stil- oder Konsistenz-Bedarf gibt, bitte ich direkt darum oder füge zusätzliche Commits mit den erforderlichen Änderungen hinzu.

### Den Code überprüfen

    """
    Create an item with all the information:

    - **name**: each item must have a name
    - **description**: a long description
    - **price**: required
    - **tax**: if the item doesn't have tax, you can omit this
    - **tags**: a set of unique tag strings for this item
    """

* `allowed_hosts` - A list of domain names that should be allowed as hostnames. Wildcard domains such as `*.example.com` are supported for matching subdomains. To allow any hostname either use `allowed_hosts=["*"]` or omit the middleware.

If an incoming request does not validate correctly then a `400` response will be sent.

## `GZipMiddleware`

Handles GZip responses for any request that includes `"gzip"` in the `Accept-Encoding` header.