数据库方案设计11.11促销活动

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

Base = declarative_base()

class Product(Base):
    __tablename__ = 'products'
    id = Column(Integer, primary_key=True)
    name = Column(String)
    stock = Column(Integer)

class Order(Base):
    __tablename__ = 'orders'
    id = Column(Integer, primary_key=True)
    product_id = Column(Integer, ForeignKey('products.id'))
    quantity = Column(Integer)
    product = relationship("Product")

engine = create_engine('mysql+pymysql://user:password@host/dbname')
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()

# 创建订单示例
def create_order(product_id, quantity):
    product = session.query(Product).filter_by(id=product_id).first()
    if product and product.stock >= quantity:
        product.stock -= quantity
        new_order = Order(product_id=product_id, quantity=quantity)
        session.add(new_order)
        session.commit()
        return True
    return False