/// note | Hinweis

Wenn Sie eine <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a> definieren, listen Sie den spezifischeren Typ zuerst auf, gefolgt vom weniger spezifischen Typ. Im Beispiel unten steht `PlaneItem` vor `CarItem` in `Union[PlaneItem, CarItem]`.

///

/// note | Примечание

При объявлении <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>, сначала указывайте наиболее детальные типы, затем менее детальные. В примере ниже более детальный `PlaneItem` стоит перед `CarItem` в `Union[PlaneItem, CarItem]`.

///

	var personAddressInfoList []*PersonAddressInfo
	if err := DB.Select("people.*, addresses.*").
		Table("people").
		Joins("inner join person_addresses on people.id = person_addresses.person_id").
		Joins("inner join addresses on person_addresses.address_id = addresses.id").
		Find(&personAddressInfoList).Error; err != nil {
		t.Errorf("Failed to run join query, got error: %v", err)
	}

						}
					} else if names := utils.SplitNestedRelationName(column); len(names) > 1 { // has nested relation
						aliasName := utils.JoinNestedRelationNames(names[0 : len(names)-1])
						for _, join := range db.Statement.Joins {
							if join.Alias == aliasName {
								names = append(strings.Split(join.Name, "."), names[len(names)-1])
								break
							}
						}

						if rel, ok := sch.Relationships.Relations[names[0]]; ok {

/// note | Nota

Ao definir um <a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>, inclua o tipo mais específico primeiro, seguido pelo tipo menos específico. No exemplo abaixo, o tipo mais específico `PlaneItem` vem antes de `CarItem` em `Union[PlaneItem, CarItem]`.

		t.Fatalf("Build count with select, but got %v", result.Statement.SQL.String())
	}

	var count4 int64
	if err := DB.Table("users").Joins("LEFT JOIN companies on companies.name = users.name").Where("users.name = ?", user1.Name).Count(&count4).Error; err != nil || count4 != 1 {
		t.Errorf("count with join, got error: %v, count %v", err, count4)
	}

	var result User

	newDB := DB.Session(&gorm.Session{NewDB: true, DryRun: true}).Table("users")

	newDB.Clauses(
		clause.From{
			Tables: []clause.Table{{Name: "users"}},
			Joins: []clause.Join{
				{
					Table: clause.Table{Name: "companies", Raw: false},
					ON: clause.Where{
						Exprs: []clause.Expression{
							clause.Eq{
								Column: clause.Column{
									Table: "users",

/// note | Nota

/// note | 참고

<a href="https://docs.pydantic.dev/latest/concepts/types/#unions" class="external-link" target="_blank">`Union`</a>을 정의할때는 더 구체적인 타입을 먼저 포함하고, 덜 구체적인 타입을 그 뒤에 나열해야합니다. 아래 예제에서는 `Union[PlaneItem, CarItem]` 를 보면, 더 구체적인 `PlaneItem`이 `CarItem`보다 앞에 위치합니다.

///

//
// Note that returning an error here will cause the Metrics handler to return a
// 500 Internal Server Error.
type MetricsLoaderFn func(context.Context, MetricValues, *metricsCache) error

// JoinLoaders - joins multiple loaders into a single loader. The returned
// loader will call each of the given loaders in order. If any of the loaders
// return an error, the returned loader will return that error.