Wenn Sie einen Query-Parameter explizit mit `Query` auszeichnen, können Sie ihn auch eine Liste von Werten empfangen lassen, oder anders gesagt, mehrere Werte.

Um zum Beispiel einen Query-Parameter `q` zu deklarieren, der mehrere Male in der URL vorkommen kann, schreiben Sie:

=== "Python 3.10+"

    ```Python hl_lines="9"
    {!> ../../../docs_src/query_params_str_validations/tutorial011_an_py310.py!}
    ```

=== "Python 3.9+"

Чтобы это понять, представьте такую картину:

### Конкурентные бургеры

<!-- The gender neutral cook emoji "🧑‍🍳" does not render well in browsers. In the meantime, I'm using a mix of male "👨‍🍳" and female "👩‍🍳" cooks. -->

Вы идёте со своей возлюбленной 😍 в фастфуд 🍔 и становитесь в очередь, в это время кассир 💁 принимает заказы у посетителей перед вами.

## Create the database

Because now we are going to use a new database in a new file, we need to make sure we create the database with:

```Python
Base.metadata.create_all(bind=engine)
```

That is normally called in `main.py`, but the line in `main.py` uses the database file `sql_app.db`, and we need to make sure we create `test.db` for the tests.

So we add that line here, with the new file.

```Python hl_lines="16"

But I'll show you how to improve that next. 🤓

## Custom Operation IDs and Better Method Names

You can **modify** the way these operation IDs are **generated** to make them simpler and have **simpler method names** in the clients.

    <div class="termy">

    ```console
    $ Get-Command pip

    some/directory/fastapi/env/bin/pip
    ```

    </div>

If it shows the `pip` binary at `env/bin/pip` then it worked. 🎉

Make sure you have the latest pip version on your local environment to avoid errors on the next steps:

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="10"
    {!> ../../../docs_src/security/tutorial001.py!}
    ```

But that is still not that useful.

Let's make it give us the current user.

## Create a user model

First, let's create a Pydantic user model.

The same way we use Pydantic to declare bodies, we can use it anywhere else:

=== "Python 3.10+"

It was one of the first extremely fast Python frameworks based on `asyncio`. It was made to be very similar to Flask.

!!! note "Technical Details"
    It used <a href="https://github.com/MagicStack/uvloop" class="external-link" target="_blank">`uvloop`</a> instead of the default Python `asyncio` loop. That's what made it so fast.

This way, its schema will show up in the API docs user interface:

<img src="/img/tutorial/dataclasses/image01.png">

## Dataclasses in Nested Data Structures

You can also combine `dataclasses` with other type annotations to make nested data structures.

In some cases, you might still have to use Pydantic's version of `dataclasses`. For example, if you have errors with the automatically generated API documentation.

!!! tip
    **GraphQL** solves some very specific use cases.

    It has **advantages** and **disadvantages** when compared to common **web APIs**.

    Make sure you evaluate if the **benefits** for your use case compensate the **drawbacks**. 🤓

## GraphQL Libraries

Here are some of the **GraphQL** libraries that have **ASGI** support. You could use them with **FastAPI**:

### FastAPI Data Filtering

Now, for FastAPI, it will see the return type and make sure that what you return includes **only** the fields that are declared in the type.