Удаление записи flask-sqlalchemy

Сделал такие модели:

    class Editor(db.Model):
    __tablename__ = 'editors'
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer(), db.ForeignKey('users.id', ondelete='CASCADE'))
    message_id = db.Column(db.Integer(), db.ForeignKey('messages.id', ondelete='CASCADE'))
class Message(db.Model):
    __tablename__ = 'messages'
    id = db.Column(db.Integer, primary_key=True)
    text = db.Column(db.String(404))
    tags = db.Column(db.String(100), default=0)
    date = db.Column(db.DateTime, default=datetime.now())
    creator_id = db.Column(db.Integer(), db.ForeignKey('users.id', ondelete='CASCADE'))
    editor = relationship(Editor, backref="parent", passive_deletes=True)
    @property
    def serialize(self):
        return {'id': self.id, 'text': self.text, 'tags': self.tags, 'date': self.date, 'creator_id': self.creator_id}
class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(100))
    count_messages = db.Column(db.Integer, default=0)
    api_key = db.Column(db.String(32))
    message = relationship(Message, backref="parent", passive_deletes=True, cascade="all,delete")
    editor = relationship(Editor, backref="parent1", passive_deletes=True, cascade="all,delete")
    def __init__(self,*args,**kwargs):
        super(User, self).__init__(*args, **kwargs)
        self.api_key = secrets.token_urlsafe(32)
    @property
    def serialize(self):
        return {'id': self.id, 'name': self.name, 'count_messages': self.count_messages}

Когда удаляю запись из users видает такую ошибку:

sqlalchemy.exc.IntegrityError: (pymysql.err.IntegrityError) (1451, 'Cannot delete or update a parent row: a foreign key constraint fails (lab_5.editors, CONSTRAINT editors_ibfk_1 FOREIGN KEY (user_id) REFERENCES users (id))') [SQL: DELETE FROM users WHERE users.id = %(id)s] [parameters: {'id': 1}] (Background on this error at: http://sqlalche.me/e/gkpj)

Удаляю так:

db.session.delete(u)
db.session.commit()