SQLAlchemy + Postgres:合并时“可能需要添加显式类型转换”

from sqlalchemy import create_engine, Column, Integer, String
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.sql import func

# 创建数据库连接
engine = create_engine('postgresql://username:password@localhost:5432/database_name')
Session = sessionmaker(bind=engine)
session = Session()

# 创建基类
Base = declarative_base()

# 定义模型类
class User(Base):
    __tablename__ = 'users'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    age = Column(Integer)

# 合并操作
query = session.query(User.name, func.sum(User.age)).group_by(User.name)
result = query.all()

# 显式类型转换
converted_result = [(str(name), int(age)) for name, age in result]

# 打印结果
for name, age in converted_result:
    print(f"Name: {name}, Age: {age}")

# 关闭数据库连接
session.close()