}
            }
        }

        if (member instanceof JApiField) {

            JApiField field = (JApiField) member
            CtField oldField = field.oldFieldOptional.get()
            CtField newField = field.newFieldOptional.get()

            def oldNullability = hasNullableAnnotation(oldField)
            def newNullability = hasNullableAnnotation(newField)

    new_field.required = field.required  # type: ignore[misc]
    new_field.model_config = field.model_config  # type: ignore[attr-defined]
    new_field.field_info = field.field_info
    new_field.allow_none = field.allow_none  # type: ignore[attr-defined]
    new_field.validate_always = field.validate_always  # type: ignore[attr-defined]
    if field.sub_fields:  # type: ignore[attr-defined]

	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

}

// ParseUniqueConstraints parse schema unique constraints
func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
	uniques := make(map[string]UniqueConstraint)
	for _, field := range schema.Fields {
		if field.Unique {
			name := schema.namer.UniqueName(schema.Table, field.DBName)
			uniques[name] = UniqueConstraint{Name: name, Field: field}
		}
	}
	return uniques

      throws IllegalAccessException {
    for (Field field : relevantFields(clazz)) {
      assertEquals(
          upperToHttpHeaderName(field.getName(), specialCases, uppercaseAcronyms), field.get(null));
    }
  }

  // Visible for other tests to use
  static ImmutableSet<Field> relevantFields(Class<?> cls) {
    ImmutableSet.Builder<Field> builder = ImmutableSet.builder();
    for (Field field : cls.getDeclaredFields()) {
      /*

			}

			if stmt.Schema != nil {
				if field := stmt.Schema.LookUpField(k); field != nil {
					if field.DBName != "" {
						if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
							set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: kv})
							assignValue(field, value[k])
						}
					} else if v, ok := selectColumns[field.Name]; (ok && v) || (!ok && !restricted) {

        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        final String field = getSearchField(context.getDefaultField(), prefixQuery.getField());
        final String text = prefixQuery.getPrefix().text();

        if (Constants.DEFAULT_FIELD.equals(field)) {
            context.addFieldLog(field, text + "*");
            context.addHighlightedQuery(text);

     * @param field
     *            フィールド。{@literal null}であってはいけません
     */
    public FieldDescImpl(final BeanDesc beanDesc, final Field field) {
        assertArgumentNotNull("beanDesc", beanDesc);
        assertArgumentNotNull("field", field);

        this.beanDesc = beanDesc;
        this.field = field;
        fieldName = field.getName();
        fieldType = field.getType();

                    "msg": "Field required",
                    "input": None,
                }
            ]
        }
    ) | IsDict(
        # TODO: remove when deprecating Pydantic v1
        {
            "detail": [
                {
                    "loc": ["body", "password"],
                    "msg": "field required",
                    "type": "value_error.missing",

!!! tip "提示"

    注意，模型属性的类型、默认值及 `Field` 的代码结构与*路径操作函数*的参数相同，只不过是用 `Field` 替换了`Path`、`Query`、`Body`。

## 添加更多信息

`Field`、`Query`、`Body` 等对象里可以声明更多信息，并且 JSON Schema 中也会集成这些信息。

*声明示例*一章中将详细介绍添加更多信息的知识。

## 小结

Pydantic 的 `Field` 可以为模型属性声明更多校验和元数据。