FastAPI sql 모델은 데이터베이스에서 모든 행을 가져옵니다.

단식이 있다Postgres 13 데이터베이스에서 모든 것을 가져오기 위해 GET 경로를 제공해야 하는 API 응용 프로그램. 항목이 정의되고 다른 앱에서 추가됩니다. 항목에는 다음과 같은 모델이 있습니다.

class ItemDb(SQLModel, table=True):
    __tablename__ = "items"
    id: str = Field(
        default_factory=uuid.uuid4, primary_key=True)
    name: str

테이블도 있습니다. 모두 다음을 가리키는 외래 키를 가지고 있습니다.

class GadgetDb(SQLModel, table=True):
    __tablename__ = "gadgets"
    id: str = Field(
        default_factory=uuid.uuid4, primary_key=True)
    item_id: str = Field(..., foreign_key="items.id")
    name: str

내 앱에서, 나는 일단 모든 것을 검색하고 싶다. 다음과 같은 간단한 모델을 만들었습니다.

class Item(SQLModel):
    id: str
    key_name: str

이것은 나의 crud 함수이다.

class CRUDItem(CRUDBase[Item, None, None]):

    def list(self, db: Session) -> List[Item]:
        statement = select(self.model)
        results = db.exec(statement)
        return results.all()


item = CRUDItem(Item)

그리고 이것이 나의 엔드포인트 기능이다.

from app.crud.crud_item import item

@router.get(
    "/",
    response_model=List[Item],
    status_code=200,
    response_model_exclude_unset=True,
)
def list_items(
    session: Session = Depends(get_session),
) -> Any:
    items = item.list(session)
    return items

그러면 오류가 반환됩니다. 이 오류가 발생하는 이유와 데이터베이스에서 모든 행을 가져오려면 어떻게 해야 합니까?

편집. 오류 추적:

INFO:     172.30.0.1:51432 - "GET /api/v1/items/ HTTP/1.1" 500 Internal Server Error
ERROR:    Exception in ASGI application
Traceback (most recent call last):
  File "/usr/local/lib/python3.9/site-packages/uvicorn/protocols/http/httptools_impl.py", line 404, in run_asgi
    result = await app(  # type: ignore[func-returns-value]
  File "/usr/local/lib/python3.9/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
    return await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/fastapi/applications.py", line 270, in __call__
    await super().__call__(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/applications.py", line 124, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/cors.py", line 84, in __call__
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/exceptions.py", line 75, in __call__
    raise exc
  File "/usr/local/lib/python3.9/site-packages/starlette/middleware/exceptions.py", line 64, in __call__
    await self.app(scope, receive, sender)
  File "/usr/local/lib/python3.9/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/usr/local/lib/python3.9/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 680, in __call__
    await route.handle(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 275, in handle
    await self.app(scope, receive, send)
  File "/usr/local/lib/python3.9/site-packages/starlette/routing.py", line 65, in app
    response = await func(request)
  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 231, in app
    raw_response = await run_endpoint_function(
  File "/usr/local/lib/python3.9/site-packages/fastapi/routing.py", line 162, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/usr/local/lib/python3.9/site-packages/starlette/concurrency.py", line 41, in run_in_threadpool
    return await anyio.to_thread.run_sync(func, *args)
  File "/usr/local/lib/python3.9/site-packages/anyio/to_thread.py", line 31, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
  File "/usr/local/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 937, in run_sync_in_worker_thread
    return await future
  File "/usr/local/lib/python3.9/site-packages/anyio/_backends/_asyncio.py", line 867, in run
    result = context.run(func, *args)
  File "/app/./app/api/api_v1/endpoints/items.py", line 29, in list_items
    results = session.exec(select(Item)).all()
  File "/usr/local/lib/python3.9/site-packages/sqlmodel/sql/expression.py", line 450, in select
    return SelectOfScalar._create(*entities, **kw)  # type: ignore
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/sql/selectable.py", line 5309, in _create
    return cls.create_legacy_select(*args, **kw)
  File "<string>", line 2, in create_legacy_select
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/util/deprecations.py", line 402, in warned
    return fn(*args, **kwargs)
  File "/usr/local/lib/python3.9/site-packages/sqlalchemy/sql/selectable.py", line 5165, in create_legacy_select
    self._raw_columns = [
TypeError: 'ModelMetaclass' object is not iterable

편집2. 클래스:

ModelType = TypeVar("ModelType", bound=Base)
CreateSchemaType = TypeVar("CreateSchemaType", bound=BaseModel)
UpdateSchemaType = TypeVar("UpdateSchemaType", bound=BaseModel)


class CRUDBase(Generic[ModelType, CreateSchemaType, UpdateSchemaType]):  # 1
    def __init__(self, model: Type[ModelType]):  # 2
    """
    CRUD object with default methods to Create, Read, Update, Delete (CRUD).
    **Parameters**
    * `model`: A SQLAlchemy model class
    * `schema`: A Pydantic model (schema) class
    """
    self.model = model

    def get(self, db: Session, id: Any) -> Optional[ModelType]:
        return db.query(self.model).filter(self.model.id == id).first()  # 3

    def list(
        self, db: Session, *, skip: int = 0, limit: int = 100
    ) -> List[ModelType]:
        return db.query(self.model).offset(skip).limit(limit).all()  # 4

    def create(self, db: Session, *, obj_in: CreateSchemaType) -> ModelType:
        obj_in_data = jsonable_encoder(obj_in)
        db_obj = self.model(**obj_in_data)  # type: ignore
        db.add(db_obj)
        db.commit()  # 5
        db.refresh(db_obj)
        return db_obj

클래스는 ORM 모델(없음)이 아니므로 데이터베이스 쿼리에서 사용할 수 없습니다. 를 사용하면 문제가 해결됩니다.