gistfile1.py

class Customers(Base):

    __tablename__ = 'customers'
    id = Column(Integer, primary_key=True)
    name = Column(Unicode)
    description = Column(Unicode)

class Accounts(Base):

    __tablename__ = 'accounts'
    id = Column(Integer, primary_key=True)
    customer_id = Column(Integer, ForeignKey('customers.id'))
    name = Column(Unicode)
    description = Column(Unicode)

class Contacts(Base):

    __tablename__ = 'contacts'
    id = Column(Integer, primary_key=True)
    customer_id = Column(Integer, ForeignKey('customers.id'))
    first = Column(Unicode)
    last = Column(Unicode)
    email = Column(Unicode)
    office_phone = Column(Unicode)
    mobile_phone = Column(Unicode)
    fax = Column(Unicode)