<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<h2>Query Syntax</h2>
<dl>
	<dt>Field</dt>
	<dd>
		You can search any field by typing the field name followed by a colon
		":" and then the term you are looking for. If you want to find
		documents which has "Fess" as the document title, you can enter:
		<pre>title:Fess</pre>
		The available fields are "url", "host", "site", "title", "content",

					switch column := eq.Column.(type) {
					case string:
						if field := db.Statement.Schema.LookUpField(column); field != nil {
							db.AddError(field.Set(db.Statement.Context, db.Statement.ReflectValue, eq.Value))
						}
					case clause.Column:
						if field := db.Statement.Schema.LookUpField(column.Name); field != nil {
							db.AddError(field.Set(db.Statement.Context, db.Statement.ReflectValue, eq.Value))
						}
					}

	// ErrModelValueRequired model value required
	ErrModelValueRequired = errors.New("model value required")
	// ErrModelAccessibleFieldsRequired model accessible fields required
	ErrModelAccessibleFieldsRequired = errors.New("model accessible fields required")
	// ErrSubQueryRequired sub query required
	ErrSubQueryRequired = errors.New("sub query required")
	// ErrInvalidData unsupported data

                )
    new_field = create_model_field(name=field.name, type_=use_type)
    new_field.has_alias = field.has_alias  # type: ignore[attr-defined]
    new_field.alias = field.alias  # type: ignore[misc]
    new_field.class_validators = field.class_validators  # type: ignore[attr-defined]
    new_field.default = field.default  # type: ignore[misc]
    new_field.required = field.required  # type: ignore[misc]

        final String[] fields = getParamValueArray(request, "facet.field");
        final String[] queries = getParamValueArray(request, "facet.query");
        if (fields.length == 0 && queries.length == 0) {
            return null;
        }
        final FacetInfo facetInfo = new FacetInfo();
        facetInfo.field = fields;
        facetInfo.query = queries;

	user, err := schema.Parse(&UserWithPermissionControl{}, &sync.Map{}, schema.NamingStrategy{})
	if err != nil {
		t.Fatalf("Failed to parse user with permission, got error %v", err)
	}

	fields := []*schema.Field{
		{Name: "ID", DBName: "id", BindNames: []string{"ID"}, DataType: schema.Uint, PrimaryKey: true, Size: 64, Creatable: true, Updatable: true, Readable: true, HasDefaultValue: true, AutoIncrement: true},

```

////

//// tab | Python 3.8+

```Python hl_lines="15-23"
{!> ../../docs_src/schema_extra_example/tutorial001.py!}
```

////

这些额外的信息将按原样添加到输出的JSON模式中。

## `Field` 的附加参数

在 `Field`, `Path`, `Query`, `Body` 和其他你之后将会看到的工厂函数，你可以为JSON 模式声明额外信息，你也可以通过给工厂函数传递其他的任意参数来给JSON 模式声明额外信息，比如增加 `example`:

//// tab | Python 3.10+

```Python hl_lines="2  8-11"

func (z *xlMetaDataDirDecoder) 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
	}
	var zb0001Mask uint8 /* 1 bits */
	_ = zb0001Mask
	for zb0001 > 0 {
		zb0001--
		field, err = dc.ReadMapKeyPtr()
		if err != nil {
			err = msgp.WrapError(err)
			return
		}

            {
                "type": "value_error.missing",
                "loc": ["body", "username"],
                "msg": "field required",
            },
            {
                "type": "value_error.missing",
                "loc": ["body", "password"],
                "msg": "field required",
            },
        ]
    }


# TODO: remove when deprecating Pydantic v1
@needs_pydanticv1

		"PFAndESI":                  "pf_and_esi",
		"AbcAndJkl":                 "abc_and_jkl",
		"EmployeeID":                "employee_id",
		"SKU_ID":                    "sku_id",
		"FieldX":                    "field_x",
		"HTTPAndSMTP":               "http_and_smtp",
		"HTTPServerHandlerForURLID": "http_server_handler_for_url_id",
		"UUID":                      "uuid",
		"HTTPURL":                   "http_url",