사실, FastAPI는 내부적으로 이 두 데코레이터를 사용합니다.

///

## `yield`를 사용하는 데이터베이스 의존성

예를 들어, 이 기능을 사용하면 데이터베이스 세션을 생성하고 작업이 끝난 후에 세션을 종료할 수 있습니다.

응답을 생성하기 전에는 `yield`문을 포함하여 그 이전의 코드만이 실행됩니다:

{* ../../docs_src/dependencies/tutorial007.py hl[2:4] *}

yield된 값은 *경로 작업* 및 다른 의존성들에 주입되는 값 입니다:

{* ../../docs_src/dependencies/tutorial007.py hl[4] *}

`yield`문 다음의 코드는 응답을 생성한 후 보내기 전에 실행됩니다:

* dockershim now makes an Image's Labels available in the Info field of ImageStatusResponse ([#58036](https://github.com/kubernetes/kubernetes/pull/58036), [@shlevy](https://github.com/shlevy))

* Support GetLabelsForVolume in OpenStack Provider ([#58871](https://github.com/kubernetes/kubernetes/pull/58871), [@edisonxiang](https://github.com/edisonxiang))

* Port-forward: use out and error streams instead of glog ([#17030](https://github.com/kubernetes/kubernetes/pull/17030), [@csrwng](https://github.com/csrwng))
* Promote Pod Hostname & Subdomain to fields (were annotations) ([#24362](https://github.com/kubernetes/kubernetes/pull/24362), [@ArtfulCoder](https://github.com/ArtfulCoder))

 * for details.
 * </td>
 * </tr>
 *
 * <tr>
 * <td >
 * <code>smb://domain;username:password@server/share/path/to/file.txt</code></td>
 * <td>
 * A prototypical example that uses all the fields.
 * </td>
 * </tr>
 *
 * <tr>
 * <td >
 * <code>smb://server/share/path/to/dir &lt;-- ILLEGAL </code></td>
 * <td>
 * URLs that represent servers, shares, or directories require a trailing slash '/'.

    public void test_annotationHashCodeAndEquals() throws Exception {
        final Field field1 = UriTypeTest.class.getDeclaredField("testFieldWeb");
        final UriType annotation1 = field1.getAnnotation(UriType.class);

        final Field field2 = UriTypeTest.class.getDeclaredField("testFieldFile");
        final UriType annotation2 = field2.getAnnotation(UriType.class);

 * for details.
 * </td></tr>
 *
 * <tr><td >
 * <code>smb1://domain;username:password@server/share/path/to/file.txt</code></td><td>
 * A prototypical example that uses all the fields.
 * </td></tr>
 *
 * <tr><td ><code>smb1://myworkgroup/angus/ &lt;-- ILLEGAL </code></td><td>
 * Despite the hierarchial relationship between workgroups, servers, and
 * filesystems this example is not valid.

        Map<String, Object> source;
        while ((source = reader.read()) != null) {
            assertTrue(source.get("field1").toString().startsWith("test"));
            valueSet.add(source.get("field1").toString());
            count++;
        }
        assertEquals(num, count);
        assertEquals(num, valueSet.size());
    }

    @Test

    *   Use `tensorflow::OkStatus()` instead of `tensorflow::Status::OK()`.
    *   Stop constructing `Status` objects from `tensorflow::error::Code`.
    *   One MUST NOT access `tensorflow::errors::Code` fields. Accessing
        `tensorflow::error::Code` fields is fine.
        *   Use the constructors such as `tensorflow::errors:InvalidArgument` to
            create status using an error code without accessing it.

# Abhängigkeiten mit yield

FastAPI unterstützt Abhängigkeiten, die nach Abschluss einige <abbr title="Manchmal auch genannt „Exit Code“, „Cleanup Code“, „Teardown Code“, „Closing Code“, „Kontext Manager Exit Code“, usw.">zusätzliche Schritte ausführen</abbr>.

Verwenden Sie dazu `yield` statt `return` und schreiben Sie die zusätzlichen Schritte / den zusätzlichen Code danach.

/// tip | Tipp

Stellen Sie sicher, dass Sie `yield` nur einmal pro Abhängigkeit verwenden.

   **FastAPI** использует их "под капотом" с этой целью.

## Зависимости с `yield` и `HTTPException`

Вы видели, что можно использовать зависимости с `yield` совместно с блоком `try`, отлавливающие исключения.

Таким же образом вы можете поднять исключение `HTTPException` или что-то подобное в завершающем коде, после `yield`.