问题 I have model like this: class User(db.Model): __tablename__ = 'users' __table_args__ = {'mysql_engine' : 'InnoDB', 'mysql_charset' : 'utf8'} id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(80), unique=True) email = db.Column(db.String(120), unique=True) _password = db.Column('password', db.String(80)) def __init__(self, username = None, email = None, password = None): self.username = username self.email = email self._set_password(password) def _set_password(self,