Sqlalchemy:如何每24小时更新一列？

from sqlalchemy import create_engine, Column, Integer, DateTime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from apscheduler.schedulers.blocking import BlockingScheduler
import datetime

# 创建数据库引擎
engine = create_engine('数据库连接字符串')

# 创建会话工厂
Session = sessionmaker(bind=engine)
session = Session()

# 创建映射基类
Base = declarative_base()

# 创建数据库表对应的映射类
class MyTable(Base):
    __tablename__ = 'my_table'
    id = Column(Integer, primary_key=True)
    column_to_update = Column(DateTime)

# 创建定时任务函数
def update_column():
    now = datetime.datetime.now()
    # 查询需要更新的行
    rows = session.query(MyTable).filter(MyTable.column_to_update < now).all()
    # 更新需要更新的行
    for row in rows:
        row.column_to_update = now
    session.commit()

# 创建定时任务调度器
scheduler = BlockingScheduler()
# 每24小时执行一次定时任务
scheduler.add_job(update_column, 'interval', hours=24)

# 启动定时任务调度器
scheduler.start()