Value(ctx context.Context, field *Field, dst reflect.Value, fieldValue interface{}) (interface{}, error)
}

// JSONSerializer json serializer
type JSONSerializer struct{}

// Scan implements serializer interface
func (JSONSerializer) Scan(ctx context.Context, field *Field, dst reflect.Value, dbValue interface{}) (err error) {
	fieldValue := reflect.New(field.FieldType)

	if dbValue != nil {
		var bytes []byte

      <version>1.0.0+</version>
      <fields>
        <field>
          <name>toolchains</name>
          <version>1.0.0+</version>
          <description>The toolchain instance definition.</description>
          <association xml.itemsStyle="flat">
            <type>ToolchainModel</type>
            <multiplicity>*</multiplicity>
          </association>
        </field>
      </fields>
      <codeSegments>

                public interface $TEST_INTERFACE_SIMPLE_NAME {
                    String field = "value";
                    void method();
                }
            """
            : """
                public class $TEST_INTERFACE_SIMPLE_NAME {
                    public String field = "value";
                    public void method() { }
                    public $TEST_INTERFACE_SIMPLE_NAME() { }

func (z *BaseOptions) DecodeMsg(dc *msgp.Reader) (err error) {
	var field []byte
	_ = field
	var zb0001 uint32
	zb0001, err = dc.ReadMapHeader()
	if err != nil {
		err = msgp.WrapError(err)
		return
	}
	for zb0001 > 0 {
		zb0001--
		field, err = dc.ReadMapKeyPtr()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}
		switch msgp.UnsafeString(field) {
		default:
			err = dc.Skip()
			if err != nil {

            {
                "type": "missing",
                "loc": ["body", "username"],
                "msg": "Field required",
                "input": {},
            },
            {
                "type": "missing",
                "loc": ["body", "password"],
                "msg": "Field required",
                "input": {},
            },
        ]
    }

            {
                "type": "missing",
                "loc": ["body", "username"],
                "msg": "Field required",
                "input": None,
            },
            {
                "type": "missing",
                "loc": ["body", "password"],
                "msg": "Field required",
                "input": None,
            },
        ]
    }

## Import `Field` { #import-field }

First, you have to import it:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

Notice that `Field` is imported directly from `pydantic`, not from `fastapi` as are all the rest (`Query`, `Path`, `Body`, etc).

///

# 请求体 - 字段

与在*路径操作函数*中使用 `Query`、`Path` 、`Body` 声明校验与元数据的方式一样，可以使用 Pydantic 的 `Field` 在 Pydantic 模型内部声明校验和元数据。

## 导入 `Field`

首先，从 Pydantic 中导入 `Field`：

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}

/// warning | 警告

注意，与从 `fastapi` 导入 `Query`，`Path`、`Body` 不同，要直接从 `pydantic` 导入 `Field` 。

///

## 声明模型属性

然后，使用 `Field` 定义模型的属性：

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[11:14] *}

## `Field` 임포트

먼저 이를 임포트해야 합니다:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}

/// warning | 경고

`Field`는 다른 것들처럼 (`Query`, `Path`, `Body` 등) `fastapi`에서가 아닌 `pydantic`에서 바로 임포트 되는 점에 주의하세요.

///

## 모델 어트리뷰트 선언

그 다음 모델 어트리뷰트와 함께 `Field`를 사용할 수 있습니다:

	public static final field TLS_KRB5_WITH_RC4_128_SHA Lokhttp3/CipherSuite;
	public static final field TLS_PSK_WITH_3DES_EDE_CBC_SHA Lokhttp3/CipherSuite;
	public static final field TLS_PSK_WITH_AES_128_CBC_SHA Lokhttp3/CipherSuite;
	public static final field TLS_PSK_WITH_AES_256_CBC_SHA Lokhttp3/CipherSuite;
	public static final field TLS_PSK_WITH_RC4_128_SHA Lokhttp3/CipherSuite;