在下单时获取产品库存变化的相关订单id

CREATE TABLE products (
    product_id INT PRIMARY KEY,
    stock INT NOT NULL
);

CREATE TABLE orders (
    order_id INT PRIMARY KEY AUTO_INCREMENT,
    product_id INT,
    quantity INT,
    status VARCHAR(50),
    FOREIGN KEY (product_id) REFERENCES products(product_id)
);

def place_order(product_id, quantity):
    # 检查库存是否充足
    product = get_product_by_id(product_id)
    if product.stock < quantity:
        raise Exception("Insufficient stock")

    # 创建订单
    order_id = create_new_order(product_id, quantity)

    # 更新库存
    update_stock(product_id, -quantity)

    return order_id

def get_product_by_id(product_id):
    # 从数据库查询产品信息
    pass

def create_new_order(product_id, quantity):
    # 插入新订单到数据库
    pass

def update_stock(product_id, change):
    # 更新产品的库存数量
    pass

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'
    product_id = Column(Integer, primary_key=True)
    stock = Column(Integer, nullable=False)

class Order(Base):
    __tablename__ = 'orders'
    order_id = Column(Integer, primary_key=True, autoincrement=True)
    product_id = Column(Integer, ForeignKey('products.product_id'))
    quantity = Column(Integer)
    status = Column(String)

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

def place_order(product_id, quantity):
    product = session.query(Product).filter_by(product_id=product_id).first()
    if product.stock < quantity:
        raise Exception("Insufficient stock")

    new_order = Order(product_id=product_id, quantity=quantity, status="Pending")
    session.add(new_order)
    session.commit()

    product.stock -= quantity
    session.commit()

    return new_order.order_id