Виктор Коровин

class F(BaseTable):
    __tablename__ = "fabcs"
    a_id = Column(Integer, ForeignKey("persons.id"))
    b_id = Column(Integer, ForeignKey("persons.id"))
    c_id = Column(Integer, ForeignKey("persons.id"))
    a = relationship('Person', foreign_keys=[a_id])
    b = relationship('Person', foreign_keys=[b_id])
    c = relationship('Person', foreign_keys=[c_id])