flask SQLAlchemy模型属性和MySQL数据库数据类

使用：

...
db = SQLAlchemy()
...
class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(64), index=True, unique=True)
    email = db.Column(db.String(120), index=True, unique=True)
    password_hash = db.Column(db.String(128))
    about_me = db.Column(db.String(140))
    info = db.Column(db.Text)
    last_seen = db.Column(db.DateTime, default=datetime.utcnow)

    def __repr__(self):
        return '<User {}>'.format(self.username)

参考:http://blog.51cto.com/13914991/2172809