如何用Mariadb在python sqlalchemy中定义DateTime？

pip install sqlalchemy
pip install pymysql

from sqlalchemy import create_engine, Column, DateTime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

engine = create_engine('mysql+pymysql://username:password@host:port/database_name')

Session = sessionmaker(bind=engine)
session = Session()

Base = declarative_base()

class MyModel(Base):
    __tablename__ = 'my_table'
    id = Column(Integer, primary_key=True)
    created_at = Column(DateTime)

Base.metadata.create_all(engine)

from datetime import datetime

# 创建一个新的实例
new_instance = MyModel(created_at=datetime.now())

# 将实例添加到会话中
session.add(new_instance)

# 提交更改
session.commit()