"operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {

        if isinstance(generate_unique_id_function, DefaultPlaceholder):
            current_generate_unique_id: Callable[
                ["APIRoute"], str
            ] = generate_unique_id_function.value
        else:
            current_generate_unique_id = generate_unique_id_function
        self.unique_id = self.operation_id or current_generate_unique_id(self)
        # normalize enums e.g. http.HTTPStatus

from fastapi import FastAPI
from fastapi.routing import APIRoute
from pydantic import BaseModel


def custom_generate_unique_id(route: APIRoute):
    return f"{route.tags[0]}-{route.name}"


app = FastAPI(generate_unique_id_function=custom_generate_unique_id)


class Item(BaseModel):
    name: str
    price: float


class ResponseMessage(BaseModel):
    message: str


class User(BaseModel):
    username: str

## Andere Datentypen

Hier sind einige der zusätzlichen Datentypen, die Sie verwenden können:

* `UUID`:
    * Ein standardmäßiger „universell eindeutiger Bezeichner“ („Universally Unique Identifier“), der in vielen Datenbanken und Systemen als ID üblich ist.
    * Wird in Requests und Responses als `str` dargestellt.
* `datetime.datetime`:
    * Ein Python-`datetime.datetime`.

from sqlalchemy.orm import relationship

from .database import Base


class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True)
    email = Column(String, unique=True, index=True)
    hashed_password = Column(String)
    is_active = Column(Boolean, default=True)

    items = relationship("Item", back_populates="owner")


class Item(Base):
    __tablename__ = "items"

                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {

### 自定义生成唯一ID函数

FastAPI为每个*路径操作*使用一个**唯一ID**，它用于**操作ID**，也用于任何所需自定义模型的名称，用于请求或响应。

你可以自定义该函数。它接受一个 `APIRoute` 对象作为输入，并输出一个字符串。

例如，以下是一个示例，它使用第一个标签（你可能只有一个标签）和*路径操作*名称（函数名）。

然后，你可以将这个自定义函数作为 `generate_unique_id_function` 参数传递给 **FastAPI**:

=== "Python 3.9+"

    ```Python hl_lines="6-7  10"
    {!> ../../../docs_src/generate_clients/tutorial003_py39.py!}
    ```

=== "Python 3.8+"

    If you are not an "expert" in OpenAPI, you probably don't need this.

You can set the OpenAPI `operationId` to be used in your *path operation* with the parameter `operation_id`.

You would have to make sure that it is unique for each operation.

```Python hl_lines="6"
{!../../../docs_src/path_operation_advanced_configuration/tutorial001.py!}
```

### Using the *path operation function* name as the operationId

    operation["summary"] = generate_operation_summary(route=route, method=method)
    if route.description:
        operation["description"] = route.description
    operation_id = route.operation_id or route.unique_id
    if operation_id in operation_ids:
        message = (
            f"Duplicate Operation ID {operation_id} for function "
            + f"{route.endpoint.__name__}"
        )

        check_file_field(first_param)
        return first_param
    # If one field requires to embed, all have to be embedded
    # in case a sub-dependency is evaluated with a single unique body field
    # That is combined (embedded) with other body fields
    for param in flat_dependant.body_params:
        setattr(param.field_info, "embed", True)  # noqa: B010
    model_name = "Body_" + name