@app.patch("/items/{item_id}", response_model=Item)
async def update_item(item_id: str, item: Item):
    stored_item_data = items[item_id]
    stored_item_model = Item(**stored_item_data)
    update_data = item.dict(exclude_unset=True)
    updated_item = stored_item_model.copy(update=update_data)
    items[item_id] = jsonable_encoder(updated_item)

    {!> ../../../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:

# 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.

@app.patch("/items/{item_id}", response_model=Item)
async def update_item(item_id: str, item: Item):
    stored_item_data = items[item_id]
    stored_item_model = Item(**stored_item_data)
    update_data = item.dict(exclude_unset=True)
    updated_item = stored_item_model.copy(update=update_data)
    items[item_id] = jsonable_encoder(updated_item)

def _regenerate_error_with_loc(
    *, errors: Sequence[Any], loc_prefix: Tuple[Union[str, int], ...]
) -> List[Dict[str, Any]]:
    updated_loc_errors: List[Any] = [
        {**err, "loc": loc_prefix + err.get("loc", ())}
        for err in _normalize_errors(errors)
    ]

    return updated_loc_errors


def _annotation_is_sequence(annotation: Union[Type[Any], None]) -> bool:

# 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:

        <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" %}

@app.patch("/items/{item_id}", response_model=Item)
async def update_item(item_id: str, item: Item):
    stored_item_data = items[item_id]
    stored_item_model = Item(**stored_item_data)
    update_data = item.dict(exclude_unset=True)
    updated_item = stored_item_model.copy(update=update_data)
    items[item_id] = jsonable_encoder(updated_item)

# ~~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"

Let's now see the file `sql_app/models.py`.

### Create Peewee models for our data

Now create the Peewee models (classes) for `User` and `Item`.

This is the same you would do if you followed the Peewee tutorial and updated the models to have the same data as in the SQLAlchemy tutorial.

!!! tip
    Peewee also uses the term "**model**" to refer to these classes and instances that interact with the database.