I have these data models:

class User(BaseModel, table=True):
   id: int

class Car(...):
   id: int

class Purchase(...):
   id: int
   user_id: int
   car_id: int

I want to create a query that checks (when committing a purchase); if the relevant user and car exists in MySQL with SQLAlchemy and Python

I have tried this statement:

user_ids= select(User.id)
car_ids = select(Car.id)
statement = select(Purchase).where(and_(
Purchase.user_id.in_(user_ids),
Purchase.car_id.in_(car_ids)
        ))
records = self._run_select_query(statement)

def _run_select_query(self, statement) -> list:
    with Session(self._engine) as session:
        results = session.exec(statement)
        return list(results.all())

But the returned records object is an empty list