如何将每个项目添加为新记录，而无需在购物车中更新

CREATE TABLE items (
    id INT AUTO_INCREMENT PRIMARY KEY,
    product_name VARCHAR(255),
    quantity INT,
    price DECIMAL(10, 2)
);

INSERT INTO items (product_name, quantity, price) VALUES ('Product A', 2, 19.99);
INSERT INTO items (product_name, quantity, price) VALUES ('Product B', 1, 29.99);

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

Base = declarative_base()

class Item(Base):
    __tablename__ = 'items'
    id = Column(Integer, primary_key=True)
    product_name = Column(String)
    quantity = Column(Integer)
    price = Column(Float)

engine = create_engine('sqlite:///example.db')
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()

# 添加新项目
new_item1 = Item(product_name='Product A', quantity=2, price=19.99)
new_item2 = Item(product_name='Product B', quantity=1, price=29.99)

session.add(new_item1)
session.add(new_item2)
session.commit()