Sie können dieselben Validierungs-Funktionen und -Tools verwenden, die Sie für Pydantic-Modelle verwenden, z. B. verschiedene Datentypen und zusätzliche Validierungen mit `Field()`.

{* ../../docs_src/settings/tutorial001_py39.py hl[2,5:8,11] *}

/// tip | Tipp

Für ein schnelles Copy-and-paste verwenden Sie nicht dieses Beispiel, sondern das letzte unten.

///

func TestFields(t *testing.T) {
	for _, tt := range fieldstests {
		b := []byte(tt.s)
		a := Fields(b)

		// Appending to the results should not change future results.
		var x []byte
		for _, v := range a {
			x = append(v, 'z')
		}

		result := sliceOfString(a)
		if !slices.Equal(result, tt.a) {
			t.Errorf("Fields(%q) = %v; want %v", tt.s, a, tt.a)
			continue
		}

from typing import Annotated, Any, Callable, Optional, Union

from fastapi.exceptions import FastAPIDeprecationWarning
from fastapi.openapi.models import Example
from pydantic import AliasChoices, AliasPath
from pydantic.fields import FieldInfo
from typing_extensions import Literal, deprecated

from ._compat import (
    Undefined,
)

_Unset: Any = Undefined


class ParamTypes(Enum):
    query = "query"

	if db5.Error != nil {
		t.Errorf("Should not raise error for join where identical fields in different tables. Error: %s", db5.Error.Error())
	}

	var users6 []User
	DB.Joins("inner join pets on pets.user_id = users.id AND pets.name = @Name", user.Pets[0]).Where("users.name = ?", user.Name).First(&users6)

O Pydantic tem um comportamento especial quando você usa `Optional` ou `Union[Something, None]` sem um valor padrão. Você pode ler mais sobre isso na documentação do Pydantic sobre <a href="https://docs.pydantic.dev/2.3/usage/models/#required-fields" class="external-link" target="_blank">campos Opcionais Obrigatórios</a>.

///

## Type Hints com Metadados de Anotações { #type-hints-with-metadata-annotations }

not in V2 configuration. The MinIO implementation above is based on V2 configuration, however it has been extended to allow both DeleteMarker replication and replication of versioned deletes with the `DeleteMarkerReplication` and `DeleteReplication` fields in the replication configuration above. By default, this is set to `Disabled` unless the user specifies it while adding a replication rule.

When an object is deleted from the source bucket, the corresponding replica version will be marked...

                    Severity.ERROR,
                    Version.BASE,
                    prefix + "systemPath",
                    d.getManagementKey(),
                    "must be omitted." + " This field may only be specified for a dependency with system scope.",
                    d);
        }

        if (request.getValidationLevel() >= ModelBuildingRequest.VALIDATION_LEVEL_MAVEN_2_0) {

///

#### Datos con valores para campos con valores por defecto { #data-with-values-for-fields-with-defaults }

Pero si tus datos tienen valores para los campos del modelo con valores por defecto, como el artículo con ID `bar`:

```Python hl_lines="3  5"
{
    "name": "Bar",

    with pytest.raises(FastAPIError) as e:

        @app.get("/")
        def read_root() -> Union[Response, None]:
            return Response(content="Foo")  # pragma: no cover

    assert "valid Pydantic field type" in e.value.args[0]
    assert "parameter response_model=None" in e.value.args[0]


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

	}

	if createdByRel, ok := userSchema.Relationships.Relations["CreatedBy"]; ok {
		if createdByRel.FieldSchema != userSchema {
			t.Fatalf("expects same field schema, but got new %p, old %p", createdByRel.FieldSchema, userSchema)
		}
	} else {
		t.Fatalf("expects created by relations, but not found")
	}
}

func TestEmbeddedHas(t *testing.T) {
	type Toy struct {