class Player:
    id = db.Column(db.BIGINT, primary_key=True, autoincrement=True)

    # СВЯЗЬ \/ \/
    last_log_id = db.Column(db.BIGINT, db.ForeignKey('PlayerLog.id'), nullable=False)
    last_log_action = db.relationship('CameraOnlineHistory',
                                        # primaryjoin="Player.last_log_id == PlayerLog.id",
                                         )
    # Связь ^^^

    logs = db.relationship('PlayerLog', lazy='dynamic', back_populates='player',
                                    # primaryjoin="Player.id == PlayerLog.camera_id"
                                     )
Class PlayerLog()
    id = db.Column(db.BIGINT, primary_key=True, autoincrement=True)

    player_id = db.Column(db.BIGINT, db.ForeignKey('player.id'), index=True, nullable=False)
    player = db.relationship("Player",
                             back_populates='logs',
                             # foreign_keys='Player.id'
                             # lazy='dynamic',
                             )