Flask Sqlalchemy 自身一对多怎么写？

Question

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    parent_id = db.Column(db.Integer, default=1)
    
    #parent怎么写？
    parent = ?
    #children怎么写？
    children = ?

id parent_id
1 1
2 1
3 1

User.first.children #就是2,3

User.query.get_or_404(2).parent #就是1

Answer 1

children = db.relationship('Children',backref='childrens',lazy='dynamic')
class Children(db.Model):

__tablename__ = 'childrens'
users = db.Column(db.Integer,db.ForeignKey('users.id'))