FastAPI hat Unterstützung für `Annotated` hinzugefügt (und begonnen, es zu empfehlen) in der Version 0.95.0.

Wenn Sie eine ältere Version haben, würden Sie Fehler erhalten, beim Versuch, `Annotated` zu verwenden.

Stellen Sie sicher, dass Sie [die FastAPI-Version aktualisieren](../deployment/versions.md#upgrading-the-fastapi-versions){.internal-link target=_blank}, auf mindestens Version 0.95.1, bevor Sie `Annotated` verwenden.

///

# Migrate from Pydantic v1 to Pydantic v2 { #migrate-from-pydantic-v1-to-pydantic-v2 }

If you have an old FastAPI app, you might be using Pydantic version 1.

FastAPI version 0.100.0 had support for either Pydantic v1 or v2. It would use whichever you had installed.

FastAPI version 0.119.0 introduced partial support for Pydantic v1 from inside of Pydantic v2 (as `pydantic.v1`), to facilitate the migration to v2.

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven-test</groupId>
  <artifactId>t09-d</artifactId>
  <packaging>jar</packaging>
  <version>1.0</version>

  <dependencies>
    <dependency>
      <groupId>maven-test</groupId>
      <artifactId>t09-c</artifactId>
      <version>1.0</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>

        <artifactId>okhttp-bom</artifactId>
        <version>[5.2.0-SNAPSHOT,6.0.0-SNAPSHOT)</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.2</version>
      <scope>test</scope>
    </dependency>

  <groupId>gid</groupId>
  <version>0.1</version>

  <dependencies>
    <dependency>
      <groupId>test</groupId>
      <artifactId>a</artifactId>
      <version>0.2</version>
      <scope>system</scope>
      <systemPath>${basedir}/lib/a.jar</systemPath>
    </dependency>
    <dependency>
      <groupId>test</groupId>
      <artifactId>b</artifactId>
      <version>0.1</version>
      <scope>system</scope>

# Permit newer CUDA versions than Clang is aware of
common:cuda_clang --copt="-Wno-unknown-cuda-version"
# Set lld as the linker.
common:cuda_clang --host_linkopt="-fuse-ld=lld"
common:cuda_clang --host_linkopt="-lm"
common:cuda_clang --linkopt="-fuse-ld=lld"
common:cuda_clang --linkopt="-lm"

# Set up compilation CUDA version and paths and use the CUDA Clang toolchain.

<project>
  <parent>
    <artifactId>p1</artifactId>
    <groupId>maven</groupId>
    <version>1.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven</groupId>
  <artifactId>p2</artifactId>
  <packaging>pom</packaging>
  <name>p2</name>
  <version>1.0</version>
  <mailingLists>
    <mailingList>
      <name>mailing-list</name>
    </mailingList>
  </mailingLists>

<project>
  <parent>
    <artifactId>p0</artifactId>
    <groupId>maven.t01</groupId>
    <version>1.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven.t01</groupId>
  <artifactId>p1</artifactId>
  <packaging>pom</packaging>
  <name>p1</name>
  <version>1.0</version>
  <organization>
    <name>p1-org</name>
  </organization>

<project>
  <parent>
    <artifactId>p3</artifactId>
    <groupId>maven.t01</groupId>
    <version>1.0</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>maven.t01</groupId>
  <artifactId>p4</artifactId>
  <packaging>jar</packaging>
  <name>p4</name>
  <version>1.0</version>
  <organization>
    <name>p4-org</name>
  </organization>

-->

<project>
  <modelVersion>4.0.0</modelVersion>
  <artifactId>foo</artifactId>
  <groupId>foo</groupId>
  <version>99.44</version>
  <packaging>jar</packaging>

  <dependencies>
    <dependency>
      <groupId>gid</groupId>
      <artifactId>aid</artifactId>
      <version>1.0</version>
      <exclusions>
        <exclusion>
          <groupId></groupId>
        </exclusion>
      </exclusions>