I’m working on a FastAPI project where I need to perform a bulk deletion of jobs using SQLAlchemy. The list of job IDs to be deleted is provided via a POST request from Postman. However, I’m encountering an error related to the synchronize_session parameter in the SQLAlchemy delete method. Here is my setup:

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from pydantic import BaseModel
from typing import List
from dependency_injector.wiring import inject, Provide
from my_project.containers import Containers
from my_project.services import JobService
from my_project.models import BaseResponse

class JobIdsDTO(BaseModel):
    job_ids: List[int]

organization_router = APIRouter()

@organization_router.post(
    "/delete-bulk", summary="Delete bulk jobs by IDs", response_model=BaseResponse
)
@inject
async def delete_bulk_jobs(
    job_ids_dto: JobIdsDTO,
    authenticated_user: OAuth2PasswordBearer = Depends(validate_user),
    job_service: JobService = Depends(Provide[Containers.job_service]),
):
    job_ids = job_ids_dto.job_ids
    
    if not authenticated_user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token expired",
            headers={"WWW-Authenticate": "Bearer"},
        )

    if (
        not hasattr(authenticated_user, "admin_id")
        or authenticated_user.admin_id is None
    ):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Login with admin account to continue",
            headers={"WWW-Authenticate": "Bearer"},
        )

    return job_service.delete_bulk_jobs(
        job_ids=job_ids
    )

Service Layer:

class JobService:
    def __init__(self, jobs_dao: JobsDAO):
        self.jobs_dao = jobs_dao

    def delete_bulk_jobs(self, job_ids: List[int]) -> int:
        return self.jobs_dao.delete_bulk_jobs(job_ids)

DAO Layer

from sqlalchemy.orm import Session
from my_project.models import YourJobModel

class JobsDAO:
    def __init__(self, db_session: Session):
        self.db_session = db_session

    def delete_bulk_jobs(self, job_ids: List[int]) -> int:
        try:
            result = (
                self.db_session.query(YourJobModel)
                .filter(YourJobModel.id.in_(job_ids))
                .delete(synchronize_session="auto")
            )
            self.db_session.commit()
            return result
        except Exception as e:
            self.db_session.rollback()
            raise e

When I try to delete bulk jobs, I get the following error:

sqlalchemy.exc.ArgumentError: Valid strategies for session synchronization are 'auto', 'evaluate', 'fetch', False