SQL Alchemy与`where`子句的关系

Question

是否有可能建立这样的关系：

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

基本上，创建一个模型属性，它执行连接并且具有where子句。

GameCompany(game_id, company_id, role)

Answer 1

绝对可能。请阅读sqlalchemy文档的Specifying Alternate Join Conditions部分，并附带示例代码。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'))