# Testing a Database

!!! info
    These docs are about to be updated. 🎉

    The current version assumes Pydantic v1, and SQLAlchemy versions less than 2.0.

    The new docs will include Pydantic v2 and will use <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a> (which is also based on SQLAlchemy) once it is updated to use Pydantic v2 as well.

# Define this here and not in the main mkdocs.yml file because that one is auto
# updated and written, and the script would remove the env var
INHERIT: !ENV [INSIDERS_FILE, '../en/mkdocs.no-insiders.yml']
markdown_extensions:
  pymdownx.highlight:

# ~~Async SQL (Relational) Databases with Encode/Databases~~ (deprecated)

!!! info
    These docs are about to be updated. 🎉

    The current version assumes Pydantic v1.

    The new docs will include Pydantic v2 and will use <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a> once it is updated to use Pydantic v2 as well.

!!! warning "Deprecated"

# ~~NoSQL (Distributed / Big Data) Databases with Couchbase~~ (deprecated)

!!! info
    These docs are about to be updated. 🎉

    The current version assumes Pydantic v1.

    The new docs will hopefully use Pydantic v2 and will use <a href="https://art049.github.io/odmantic/" class="external-link" target="_blank">ODMantic</a> with MongoDB.

!!! warning "Deprecated"
    This tutorial is deprecated and will be removed in a future version.

然后再用它生成一个只含已设置（在请求中所发送）数据，且省略了默认值的 `dict`：

```Python hl_lines="34"
{!../../../docs_src/body_updates/tutorial002.py!}
```

### 使用 Pydantic 的 `update` 参数

接下来，用 `.copy()` 为已有模型创建调用 `update` 参数的副本，该参数为包含更新数据的 `dict`。

例如，`stored_item_model.copy(update=update_data)`：

```Python hl_lines="35"
{!../../../docs_src/body_updates/tutorial002.py!}
```

### 更新部分数据小结

简而言之，更新部分数据应：

    {!> ../../../docs_src/body_updates/tutorial002_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="35"
    {!> ../../../docs_src/body_updates/tutorial002_py39.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="35"
    {!> ../../../docs_src/body_updates/tutorial002.py!}
    ```

### Partial updates recap

In summary, to apply partial updates you would:

        <span class="twemoji twitter">
          {% include ".icons/fontawesome/brands/twitter.svg" %}
        </span> Follow <strong>@fastapi</strong> on <strong>Twitter</strong> to stay updated
      </a>
    </div>
    <div class="item">
      <a class="announce-link" href="https://fastapi.tiangolo.com/newsletter/">
        <span class="twemoji">
          {% include ".icons/material/email.svg" %}

    return operation_id


def deep_dict_update(main_dict: Dict[Any, Any], update_dict: Dict[Any, Any]) -> None:
    for key, value in update_dict.items():
        if (
            key in main_dict
            and isinstance(main_dict[key], dict)
            and isinstance(value, dict)
        ):
            deep_dict_update(main_dict[key], value)
        elif (
            key in main_dict

        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/{item_id}": {
                "put": {
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,

        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/{item_id}": {
                "put": {
                    "summary": "Update Item",
                    "operationId": "update_item_items__item_id__put",
                    "parameters": [
                        {
                            "required": True,