Python 炼金术中的抽象杂交性质

我正在用SQLAlchemy对现有数据库结构进行建模，并希望执行以下操作：

class Employee(AbstractConcreteBase, Base):

    @hybrid_property
    def daily_wage(self):
        pass

class HourlyEmployee(Employee):
    __tablename__ = "HourlyEmployee"

    __mapper_args__ = {
        "polymorphic_identity": "hourly",
        "concrete": True,
    }

    id = Column(Integer, primary_key=True)
    hourly_wage = Column(Float, nullable=False)

    @Employee.daily_wage.overrides.getter
    def daily_wage(self):
        return self.hourly_wage * 8


class DailyEmployee(Employee):
    __tablename__ = "DailyEmployee"

    __mapper_args__ = {
        "polymorphic_identity": "daily",
        "concrete": True,
    }

    id = Column(Integer, primary_key=True)

    wage = Column(Float, nullable=False)

    @Employee.daily_wage.overrides.getter
    def daily_wage(self):
        return self.wage

然后我想这样提问：

session.query(Employee).filter(Employee.daily_wage < 8.0).all()

session.query（Employee）.filter（Employee.daily_wage<8.0）.all（）

然而，这是行不通的