* `Field(primary_key=True)` 会告诉 SQLModel `id` 是 SQL 数据库中的**主键**（你可以在 SQLModel 文档中了解更多关于 SQL 主键的信息）。

    **注意：** 我们为主键字段使用 `int | None`，这样在 Python 代码中我们可以在没有 `id`（`id=None`）的情况下创建对象，并假定数据库在保存时会生成它。SQLModel 会理解数据库会提供 `id`，并在数据库模式中将该列定义为非空的 `INTEGER`。详见 [SQLModel 关于主键的文档](https://sqlmodel.tiangolo.com/tutorial/create-db-and-table/#primary-key-id)。

    private BelowAll() {
      /*
       * No code ever sees this bogus value for `endpoint`: This class overrides both methods that
       * use the `endpoint` field, compareTo() and endpoint(). Additionally, the main implementation
       * of Cut.compareTo checks for belowAll before reading accessing `endpoint` on another Cut
       * instance.
       */
      super("");
    }

	}

	stmt := dryDB.Clauses(clause.OrderBy{
		Expression: clause.Expr{SQL: "FIELD(id,?)", Vars: []interface{}{[]int{1, 2, 3}}, WithoutParentheses: true},
	}).Find(&User{}).Statement

	explainedSQL := dryDB.Dialector.Explain(stmt.SQL.String(), stmt.Vars...)
	if !regexp.MustCompile("SELECT \\* FROM .*users.* ORDER BY FIELD\\(id,1,2,3\\)").MatchString(explainedSQL) {
		t.Fatalf("Build Order condition, but got %v", explainedSQL)

</div>

### `Settings` 객체 만들기 { #create-the-settings-object }

Pydantic에서 `BaseSettings`를 import하고, Pydantic 모델과 매우 비슷하게 서브클래스를 만드세요.

Pydantic 모델과 같은 방식으로, 타입 어노테이션(그리고 필요하다면 기본값)과 함께 클래스 속성을 선언합니다.

다양한 데이터 타입, `Field()`로 추가 검증 등 Pydantic 모델에서 사용하는 동일한 검증 기능과 도구를 모두 사용할 수 있습니다.

{* ../../docs_src/settings/tutorial001_py310.py hl[2,5:8,11] *}

/// tip | 팁

빠르게 복사/붙여넣기할 예시가 필요하다면, 이 예시는 사용하지 말고 아래의 마지막 예시를 사용하세요.

///

**GSA Configuration Mapping**

| GSA Setting | Fess Equivalent |
|-------------|----------------|
| Collection | WebConfig or FileConfig |
| Start URLs | URLs field in crawl config |
| Good URL Pattern | Included URLs (regex) |
| Bad URL Pattern | Excluded URLs (regex) |
| Follow/Index Pattern | Config Depth and Filter settings |

**Implementation Details**

在这些情况下，你可以使用**自定义校验函数**，该函数会在正常校验之后应用（例如，在先校验值是 `str` 之后）。

你可以在 `Annotated` 中使用 [Pydantic 的 `AfterValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator) 来实现。

/// tip | 提示

Pydantic 还有 [`BeforeValidator`](https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator) 等。🤓

///

        void testSetDcerpcSecurityProvider() {
            // When: Setting security provider
            handle.setDcerpcSecurityProvider(mockSecurityProvider);

            // Then: Should not throw exception (private field, no direct verification)
            assertDoesNotThrow(() -> handle.setDcerpcSecurityProvider(mockSecurityProvider));
        }

        @Test
        @DisplayName("Should handle close operation")

		t.Fatal(err)
	}

	// Check if the reference format and input formats are same.
	if err = formatErasureV3Check(quorumFormat, formats[0]); err != nil {
		t.Fatal(err)
	}

	// QuorumFormat has .This field empty on purpose, expect a failure.
	if err = formatErasureV3Check(formats[0], quorumFormat); err == nil {
		t.Fatal("Unexpected success")
	}

	formats[0] = nil
	quorumFormat, err = getFormatErasureInQuorum(formats)

  with its <<<DefaultInheritanceAssembler>>> implementation
  ({{{./xref/org/apache/maven/model/inheritance/DefaultInheritanceAssembler.html}source}}).

  By default, every model field is inherited as-is from parent, with a few exceptions that are intentionally not inherited:
  <<<modelVersion>>>, <<<artifactId>>>, <<<packaging>>>, <<<profiles>>> (injected in phase 1) and <<<prerequisites>>>.

}

// Check to see if Policy is signed correctly.
func doesPolicySignatureMatch(formValues http.Header) (auth.Credentials, APIErrorCode) {
	// For SignV2 - Signature field will be valid
	if _, ok := formValues[xhttp.AmzSignatureV2]; ok {
		return doesPolicySignatureV2Match(formValues)
	}
	return doesPolicySignatureV4Match(formValues)
}