# Body - Fields { #body-fields }

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

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

First, you have to import it:

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


/// warning

## `Field`のインポート

まず、以下のようにインポートします:

{* ../../docs_src/body_fields/tutorial001.py hl[4] *}

/// warning | 注意

`Field`は他の全てのもの（`Query`、`Path`、`Body`など）とは違い、`fastapi`からではなく、`pydantic`から直接インポートされていることに注意してください。

///

## モデルの属性の宣言

以下のように`Field`をモデルの属性として使用することができます:

    }

    public void test_setResponseFields() {
        String[] fields = { "field1", "field2", "field3" };
        queryFieldConfig.setResponseFields(fields);

        assertSame(fields, queryFieldConfig.responseFields);
    }

    public void test_getScrollResponseFields() {
        String[] fields = { "scroll1", "scroll2", "scroll3" };
        queryFieldConfig.setScrollResponseFields(fields);

        String[] roles = { "role2", "role1" };
        String[] fields = { "field2", "field1" };
        String[] excludes = { "exclude2", "exclude1" };

        String result1 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);
        String result2 = popularWordHelper.getCacheKey(seed, tags, roles, fields, excludes);

        assertEquals(result1, result2);
    }

        List<String> readings = Arrays.asList("reading1", "reading2");
        List<String> fields = Arrays.asList("field1", "field2", "field3");
        List<String> tags = Arrays.asList("tag1", "tag2");
        List<String> roles = Arrays.asList("role1", "role2", "role3");

        elevateWord = new ElevateWord(word, boost, readings, fields, tags, roles);
        SuggestItem suggestItem = elevateWord.toSuggestItem();

        facetInfo.size = 20;
        facetInfo.sort = "term.asc";

        String result = facetInfo.toString();
        assertEquals("FacetInfo [field=[field1], query=null, size=20, minDocCount=null, sort=term.asc, missing=null]", result);
    }

    // Test field assignment
    public void test_fieldAssignment() {
        String[] fields = new String[] { "field1", "field2", "field3" };

    @Test
    public void testGetKeywordsWithEmptyField() {
        // Test with empty field array
        String query = "test query";
        String[] fields = {};
        List<String> keywords = SuggestUtil.getKeywords(query, fields);
        assertNotNull(keywords);
        assertEquals(0, keywords.size()); // No keywords because no fields match
    }

    @Test
    public void testGetKeywordsWithComplexQuery() {

                    final Map<String, Object> fields = searchHit.getSourceAsMap();
                    target.setParentUrl(getFieldValue(fields.get("parentUrl"), String.class));
                    target.setMethod(getFieldValue(fields.get("method"), String.class));
                    target.setMimeType(getFieldValue(fields.get("mimeType"), String.class));
                    target.setSessionId(getFieldValue(fields.get("sessionId"), String.class));

                return fields;
            }

            @Override
            public String[] getQueryAdditionalSearchFields(String... fields) {
                return fields;
            }

            @Override
            public String[] getQueryAdditionalFacetFields(String... fields) {
                return fields;
            }

            @Override

 * <li>{@link #QUERY_FREQ} - The query frequency field.</li>
 * <li>{@link #DOC_FREQ} - The document frequency field.</li>
 * <li>{@link #USER_BOOST} - The user boost field.</li>
 * <li>{@link #KINDS} - The kinds field.</li>
 * <li>{@link #TIMESTAMP} - The timestamp field.</li>
 * <li>{@link #TAGS} - The tags field.</li>
 * <li>{@link #ROLES} - The roles field.</li>
 * <li>{@link #FIELDS} - The fields field.</li>