python - 《Flask Web 开发》 无法更新数据库

问题描述

学习到《Flask Web开发》第八章时，运行代码报错。后来意识到User表中新增了一列，应该更新数据库，执行

python manage.py db migrate -m 'initial migration'

结果报错：alembic.util.exc.CommandError: Target database is not up to date.

这种错误先前没有遇到过，网上找了一下也不理解。

相关代码app/models.py:

from . import dbfrom werkzeug.security import generate_password_hash, check_password_hashfrom flask_login import UserMixinfrom . import login_managerfrom itsdangerous import TimedJSONWebSignatureSerializer as Serializerfrom flask import current_app@login_manager.user_loaderdef load_user(user_id): return User.query.get(int(user_id))class Role(db.Model): __tablename__ = ’roles’ id = db.Column(db.Integer, primary_key = True) name = db.Column(db.String(64), unique = True) users = db.relationship(’User’, backref = ’role’, lazy = ’dynamic’)def __repr__(self):return ’<Role %r>’ % self.nameclass User(UserMixin, db.Model): __tablename__ = ’users’ id = db.Column(db.Integer, primary_key = True) email = db.Column(db.String(64), unique=True, index=True) username = db.Column(db.String(64), unique = True, index = True) role_id = db.Column(db.Integer, db.ForeignKey(’roles.id’)) password_hash = db.Column(db.String(128)) confirmed = db.Column(db.Boolean, default=False)@property def password(self):raise AttributeError(’password is not a readable attribute’)@password.setter def password(self, password):self.password_hash = generate_password_hash(password)def verify_password(self, password):return check_password_hash(self.password_hash, password)def __repr__(self):return ’<User %r>’ % self.username def generate_confirmation_token(self, expiration=3600):s = Serializer(current_app.config[’SECRET_KEY’], expiration)return s.dump({’confirm’: self.id}) def confirm(self, token):s = Serializer(current_app.config[’SECRET_KEY’])try: data = s.loads(token)except: return Falseif data.get(’confirm’) != self.id: return Falseself.confirmed = Truedb.session.add(self)return True

求指导！！！

问题解答

删除了migrations文件夹里一个版本后能正常更新了。

确定 Google 过 ?

Google 结果: https://www.google.com/search...

根据Google结果找到的SO 答案: http://stackoverflow.com/ques...