模型分离（选做）

models.py

新建models.py，将模型定义全部放到这个独立的文件中。

from datetime import datetime
from werkzeug.security import generate_password_hash,check_password_hash

from exts import db

class User(db.Model):
    __tablename__ = 'user'
    id = db.Column(db.Integer, primary_key=TabError, autoincrement=True)
    username = db.Column(db.String(20), nullable=False)
    _password = db.Column(db.String(200), nullable=False) #neibushiyong
    nickname = db.Column(db.String(20))

    @property
    def password(self):
        return self._password

    @password.setter
    def password(self, row_password):
        self._password = generate_password_hash(row_password)

    def check_password(self, row_password):
        result = check_password_hash(self._password, row_password)
        return result

class Question(db.Model):
    __tablename__ = 'question'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    title = db.Column(db.String(100), nullable=False)
    detail = db.Column(db.Text, nullable=False)
    creat_time = db.Column(db.DateTime, default=datetime.now)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    author = db.relationship('User', backref=db.backref('question'))

class Comment(db.Model):
    __tablename__='comment'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    author_id = db.Column(db.Integer, db.ForeignKey('user.id'))
    question_id = db.Column(db.Integer , db.ForeignKey('question.id'))
    creat_time = db.Column(db.DateTime,default=datetime.now)
    detail = db.Column(db.Text , nullable=False)
    question = db.relationship('Question',backref = db.backref('comments',order_by=creat_time.desc))
    author = db.relationship('User',backref = db.backref('comments'))

新建exts.py，将db = SQLAlchemy()的定义放到这个独立的文件中。

from flask_sqlalchemy import SQLAlchemy

db = SQLAlchemy()

models.py和主py文件，都从exts.py中导入db。

在主py文件中，对db进行始化，db.init_app(app)。

from models import Question,User,Comment
from exts import db

app=Flask(__name__)
app.config.from_object(config)
db.init_app(app)