SQLAlchemy的：相同類型

Question

的多個foreignKeys我具有類似於此的類：

class Component(Base): 
    __tablename__ = 'components' 

    id = Column(Integer, primary_key=True) 
    . 
    . 
    . 
    . 
    alternate1_id = Column(Integer, foreignkey("components.id"), nullable=True) 
    alternate2_id = Column(Integer, foreignkey("components.id"), nullable=True) 
    alternate3_id = Column(Integer, foreignkey("components.id"), nullable=True) 

    def __init__(self, catalog_number, component_type, manufacturer_pn, description): 
      self.catalog_number = catalog_number 
      self.component_type = component_type 
      self.manufacturer_pn = manufacturer_pn 
      self.description = description 

    def __repr__(self): 
      return "<Component('%s', '%s', '%s', '%s')>" % (self.catalog_number, 
                  self.component_type, 

alternate1，2和3是可選字段指向當前實例的替代組件。

如何創建三個關係，每個關係指向每個id的？

Answer 1

請參閱handling multiple join paths中foreign_keys參數relationship的示例。