default:
			rv := reflect.ValueOf(v)
			if v == nil || !rv.IsValid() || rv.Kind() == reflect.Ptr && rv.IsNil() {
				vars[idx] = nullStr
			} else if valuer, ok := v.(driver.Valuer); ok {
				v, _ = valuer.Value()
				convertParams(v, idx)
			} else if rv.Kind() == reflect.Ptr && !rv.IsZero() {
				convertParams(reflect.Indirect(rv).Interface(), idx)
			} else if isNumeric(rv.Kind()) {

Primeiro, é claro, você pode misturar `Path`, `Query` e declarações de parâmetro no corpo da requisição livremente e o **FastAPI** saberá o que fazer.

E você também pode declarar parâmetros de corpo como opcionais, definindo o valor padrão com `None`:

=== "Python 3.10+"

    ```Python hl_lines="17-19"
    {!> ../../../docs_src/body_multiple_params/tutorial001_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="19-21"

// systems by fcntl_linux_32bit.go to be SYS_FCNTL64.
var fcntl64Syscall uintptr = SYS_FCNTL

func fcntl(fd int, cmd, arg int) (int, error) {
	valptr, _, errno := Syscall(fcntl64Syscall, uintptr(fd), uintptr(cmd), uintptr(arg))
	var err error
	if errno != 0 {
		err = errno
	}
	return int(valptr), err
}

// FcntlInt performs a fcntl syscall on fd with the provided command and argument.
func FcntlInt(fd uintptr, cmd, arg int) (int, error) {

	builder.WriteQuoted(like.Column)
	builder.WriteString(" NOT LIKE ")
	builder.AddVar(builder, like.Value)
}

func eqNil(value interface{}) bool {
	if valuer, ok := value.(driver.Valuer); ok && !eqNilReflect(valuer) {
		value, _ = valuer.Value()
	}

	return value == nil || eqNilReflect(value)
}

func eqNilReflect(value interface{}) bool {
	reflectValue := reflect.ValueOf(value)

Errors returned by [driver.Valuer] implementations are now wrapped for
improved error handling during operations like [DB.Query], [DB.Exec],

**FastAPI** usará esa respuesta *temporal* para extraer el código de estado (también cookies y headers), y los pondrá en la respuesta final que contiene el valor que retornaste, filtrado por cualquier `response_model`.

	}

	fieldValue := reflect.New(field.IndirectFieldType)
	// if field is valuer, used its value or first field as data type
	valuer, isValuer := fieldValue.Interface().(driver.Valuer)
	if isValuer {
		if _, ok := fieldValue.Interface().(GormDataTypeInterface); !ok {
			if v, err := valuer.Value(); reflect.ValueOf(v).IsValid() && err == nil {
				fieldValue = reflect.ValueOf(v)
			}

		{"error not equal", errors.New("1"), errors.New("2"), false},
		{"driver.Valuer equal", ModifyAt{Time: now, Valid: true}, ModifyAt{Time: now, Valid: true}, true},
		{"driver.Valuer not equal", ModifyAt{Time: now, Valid: true}, ModifyAt{Time: now.Add(time.Second), Valid: true}, false},
		{"driver.Valuer equal (ptr to nil ptr)", (*ModifyAt)(nil), &ModifyAt{}, false},
	}
	for _, test := range assertEqualTests {

	}

	if err := DB.Create(&data).Error; err != nil {
		t.Fatalf("No error should happened when create scanner valuer struct, but got %v", err)
	}

	var result ScannerValuerStruct

	if err := DB.Find(&result, "id = ?", data.ID).Error; err != nil {
		t.Fatalf("no error should happen when query scanner, valuer struct, but got %v", err)
	}

	if result.ExampleStructPtr.Val != "value2" {

{!../../../docs_src/body/tutorial001.py!}
```

Tout comme pour la déclaration de paramètres de requête, quand un attribut de modèle a une valeur par défaut, il n'est pas nécessaire. Sinon, cet attribut doit être renseigné dans le corps de la requête. Pour rendre ce champ optionnel simplement, utilisez `None` comme valeur par défaut.

Par exemple, le modèle ci-dessus déclare un "objet" JSON (ou `dict` Python) tel que :

```JSON
{
    "name": "Foo",