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...

///

#### 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",

### 创建 `Settings` 对象

从 Pydantic 导入 `BaseSettings` 并创建一个子类，与 Pydantic 模型非常相似。

与 Pydantic 模型一样，您使用类型注释声明类属性，还可以指定默认值。

您可以使用与 Pydantic 模型相同的验证功能和工具，比如不同的数据类型和使用 `Field()` 进行附加验证。

{* ../../docs_src/settings/tutorial001.py hl[2,5:8,11] *}

/// tip

如果您需要一个快速的复制粘贴示例，请不要使用此示例，而应使用下面的最后一个示例。

///

Pydantic verhält sich speziell, wenn Sie `Optional` oder `Union[Something, None]` ohne einen Defaultwert verwenden. Sie können darüber in der Pydantic Dokumentation unter <a href="https://docs.pydantic.dev/2.3/usage/models/#required-fields" class="external-link" target="_blank">Erforderliche optionale Felder</a> mehr erfahren.

///

## Typhinweise mit Metadaten-Annotationen { #type-hints-with-metadata-annotations }

* A new link should be at the top of its list.
* The link URL should work (it should not return a 404).
* The content of the link should be about FastAPI.
* The new addition should have these fields:
    * `author`: The name of the author.
    * `link`: The URL with the content.
    * `title`: The title of the link (the title of the article, podcast, etc).

**Spoiler alert**: туторіал - посібник користувача містить:

* Оголошення **параметрів** з інших місць як: **headers**, **cookies**, **form fields** та **files**.
* Як встановити **перевірку обмежень** як `maximum_length` або `regex`.