# Query Parameter Models

If you have a group of **query parameters** that are related, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

## Query Parameters with a Pydantic Model

////

O **FastAPI** irá **extrair** as informações para **cada campo** dos **dados do formulário** na requisição e dar para você o modelo Pydantic que você definiu.

## Confira os Documentos

Você pode verificar na UI de documentação em `/docs`:

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Proibir Campos Extras de Formulários

<img src="/img/tutorial/response-model/image01.png">

Und beide Modelle werden auch in der interaktiven API-Dokumentation verwendet:

<img src="/img/tutorial/response-model/image02.png">

## Andere Rückgabetyp-Annotationen

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel

app = FastAPI()


class Model(BaseModel):
    pass


class Model2(BaseModel):
    a: Model


class Model3(BaseModel):
    c: Model
    d: Model2


@app.get("/", response_model=Model3)
def f():
    return {"c": {}, "d": {"a": {}}}


client = TestClient(app)


def test_get_api_route():

# Modelos de Parâmetros de Cookie

Se você possui um grupo de **cookies** que estão relacionados, você pode criar um **modelo Pydantic** para declará-los. 🍪

Isso lhe permitiria **reutilizar o modelo** em **diversos lugares** e também declarar validações e metadata para todos os parâmetros de uma vez. 😎

/// note | Nota

Isso é suportado desde a versão `0.115.0` do FastAPI. 🤓

///

/// tip | Dica

# OpenAPI `models`

OpenAPI Pydantic models used to generate and validate the generated OpenAPI.

# Cookie Parameter Models

If you have a group of **cookies** that are related, you can create a **Pydantic model** to declare them. 🍪

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

/// tip

This same technique applies to `Query`, `Cookie`, and `Header`. 😎

///

Und es wird entsprechend annotiert/dokumentiert.

## Verschachtelte Modelle

Jedes Attribut eines Pydantic-Modells hat einen Typ.

Aber dieser Typ kann selbst ein anderes Pydantic-Modell sein.

Sie können also tief verschachtelte JSON-„Objekte“ deklarieren, mit spezifischen Attributnamen, -typen, und -validierungen.

	Active    bool
}

type Account struct {
	gorm.Model
	UserID sql.NullInt64
	Number string
}

type Pet struct {
	gorm.Model
	UserID *uint
	Name   string
	Toy    Toy `gorm:"polymorphic:Owner;"`
}

type Toy struct {
	gorm.Model
	Name      string
	OwnerID   string
	OwnerType string
}

type Tools struct {
	gorm.Model
	Name     string
	CustomID string
	Type     string
}

## Nested Models

Each attribute of a Pydantic model has a type.

But that type can itself be another Pydantic model.

So, you can declare deeply nested JSON "objects" with specific attribute names, types and validations.

All that, arbitrarily nested.

### Define a submodel

For example, we can define an `Image` model:

//// tab | Python 3.10+