Cascade delete SqlAlchemy

models.py

class Parent(Model):
    __tablename__ = "parent"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String)

    
class Child(Model):
    __tablename__ = "child"

    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String)
    parent_id = db.Column(
        db.Integer,
        db.ForeignKey("parent.id"),
        nullable=False,
    )
    parent = db.relationship(
        "Parent",
        foreign_keys=parent_id,
        backref=backref("childrent", cascade="all, delete"),
    )