python SQLAchemy多外键关联

 1 from sqlalchemy import Integer, ForeignKey, String, Column
 2 from sqlalchemy.ext.declarative import declarative_base
 3 from sqlalchemy.orm import relationship
 4 from sqlalchemy import create_engine
 5 Base = declarative_base()
 6 
 7 
 8 class Customer(Base):
 9     __tablename__ = ‘customer‘
10     id = Column(Integer, primary_key=True)
11     name = Column(String(64))
12 
13     billing_address_id = Column(Integer, ForeignKey("address.id"))
14     shipping_address_id = Column(Integer, ForeignKey("address.id"))
15 
16     billing_address = relationship("Address",foreign_keys=[billing_address_id])
17     shipping_address = relationship("Address",foreign_keys=[shipping_address_id])
18 
19 
20 class Address(Base):
21     __tablename__ = ‘address‘
22     id = Column(Integer, primary_key=True)
23     street = Column(String(64))
24     city = Column(String(64))
25     state = Column(String(64))
26 
27     def __repr__(self):
28         return self.street
29 
30 engine = create_engine("mysql+pymysql://root:@localhost/test",encoding=‘utf-8‘)
31 Base.metadata.create_all(engine)  # 创建表结构