I want a user to be referral and referee, and store some additional data. Here is my code:

class User(UserMixin, db.Model):
    __tablename__ = 'user'
    referees = db.relationship('RefData', back_populates='referral', lazy='dynamic')
    referrals = db.relationship('RefData', back_populates='referee', lazy='dynamic')

and the RefData table:

class RefData(UserMixin, db.Model):
    __tablename__ = 'ref_data'

    referral_id = db.Column(UUID(as_uuid=True), db.ForeignKey('user.id'), primary_key=True)
    referral = db.relationship('User', back_populates='referrals')

    referee_id = db.Column(UUID(as_uuid=True), db.ForeignKey('user.id'), primary_key=True)
    referee = db.relationship('User', back_populates='referees')

But with this code, I have the following exception and I can’t figure out how to solve it:

sqlalchemy.exc.AmbiguousForeignKeysError: Could not determine join condition between 
parent/child tables on relationship User.referees - there are multiple foreign key paths 
linking the tables.  Specify the 'foreign_keys' argument, providing a list of those columns 
which should be counted as containing a foreign key reference to the parent table.