SQL Alchemy 与“where”子句的关系

Question

是否可以建立这样的关系：

class Games(Base):
    publishers = relationship(GameCompany).where(GameCompany.role == 'publisher')
    developers = relationship(GameCompany).where(GameCompany.role == 'developer')

本质上，创建一个执行连接并具有 where 子句的模型属性。

GameCompany(game_id, company_id, role)

Answer 1

这是绝对有可能的。请阅读文档的指定备用连接条件部分sqlalchemy以及示例代码。您的模型的代码可能如下所示：

class GameCompany(Base):
    id = Column(Integer, primary_key=True)
    company_id = Column(ForeignKey('games.id'))
    # ...

class Games(Base):
    __tablename__ = 'games'
    id = Column(Integer, primary_key=True)
    # ...
    publishers = relationship(GameCompany, 
        primaryjoin=and_(GameCompany.game_id == id, GameCompany.role == 'publisher'))
    developers = relationship(GameCompany, 
        primaryjoin=and_(GameCompany.game_id == id, GameCompany.role == 'developer'))