python - Rails 模型继承

Question

用代码示例来解释是最简单的，在Python中我可以这样做来实现模型继承:

"""Image model"""
from sqlalchemy import Column, ForeignKey
from sqlalchemy.types import Integer, String, Text
from miasto_3d.model.meta import Base

class Image(Base):
    __tablename__ = "image"
    image_id = Column(Integer, primary_key=True)
    path = Column(String(200))

    def get_mime(self):
        #function to get mime type from file
        pass



"""WorkImage model"""
class WorkImage(Image, Base):
    __tablename__ = "work_images"

    image_id = Column(Integer, ForeignKey("image.image_id"), primary_key=True)
    work_id = Column(Integer, ForeignKey("work.id"))
    work = relation("Work", backref=backref('images',order_by='WorkImage.work_id'))

"""UserAvatar model"""
class UserAvatar(Image, Base):
    __tablename__ = "user_avatars"

    image_id = Column(Integer, ForeignKey("image.image_id"), primary_key=True)
    user_id = Column(Integer, ForeignKey("user.id"))
    user = relation("User", backref=backref('images',order_by='UserAvatar.user_id'))   

我如何在 Rails 中做类似的事情？或者也许还有另一种更好的方法？我知道回形针，但我不喜欢它使用共享表来存储照片和模型数据的概念。

Answer 1

看来您想要 a polymorphic association或者single table inheritance .