如何在sqlAlchemy模型的联接查询中使用sum和count

from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
from sqlalchemy.orm import sessionmaker, relationship
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    orders = relationship('Order', back_populates='user')

class Order(Base):
    __tablename__ = 'orders'
    id = Column(Integer, primary_key=True)
    user_id = Column(Integer, ForeignKey('users.id'))
    amount = Column(Integer)
    user = relationship('User', back_populates='orders')

from sqlalchemy import create_engine, func
from sqlalchemy.orm import sessionmaker

# 创建数据库连接
engine = create_engine('数据库连接字符串')
Session = sessionmaker(bind=engine)
session = Session()

# 使用联接查询和聚合函数计算订单总金额和订单数量
result = session.query(User.name, func.sum(Order.amount), func.count(Order.id)).\
    join(Order).\
    group_by(User.name).all()

# 打印结果
for name, total_amount, order_count in result:
    print(f'用户名：{name}，订单总金额：{total_amount}，订单数量：{order_count}')