text: from sqlalchemy import (
      MetaData, Table, Column, Integer, String, Float, ForeignKey,
  )
  
  
  metadata = MetaData()
  
  
  customers = Table(
      'customers', metadata,
      Column('id', Integer, primary_key=True),
      Column('email', String),
  )
  
  products = Table(
      'products', metadata,
      Column('sku', String, primary_key=True),
      Column('title', String),
      Column('description', String),
      Column('price', Float),
  )
  
  carts = Table(
      'carts', metadata,
      Column('id', Integer, primary_key=True),
      Column('customer_id', ForeignKey('customers.id')),
  )
  
  cart_positions = Table(
      'cart_positions', metadata,
      Column('id', Integer, primary_key=True),
      Column('product_sku', ForeignKey('products.sku')),
      Column('cart_id', ForeignKey('carts.id')),
      Column('quantity', Integer),
  )
  
  orders = Table(
      'orders', metadata,
      Column('number', Integer, primary_key=True),
      Column('customer_id', ForeignKey('customers.id')),
  )
  
  order_lines = Table(
      'order_lines', metadata,
      Column('order_number', ForeignKey('orders.number'), primary_key=True),
      Column('product_sku', String),
      Column('product_title', String),
      Column('price', Float),
      Column('quantity', Integer),
  )
  