模型分离（选做）

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=True, autoincrement=True)
    username = db.Column(db.String(20), nullable=False)
    password = db.Column(db.String(20), nullable=False)
    nickname = db.Column(db.String(20), nullable=True)


class Wenda(db.Model):
    __tablename__ = ‘wenda‘
    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(‘wenda‘))

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‘))
    wenda_id = db.Column(db.Integer, db.ForeignKey(‘wenda.id‘))
    creat_time = db.Column(db.DateTime, default=datetime.now)
    detail = db.Column(db.Text, nullable=False)
    wenda = db.relationship(‘Wenda‘, backref=db.backref(‘comments‘,order_by=creat_time.desc))
    author = db.relationship(‘User‘, backref=db.backref(‘comments‘))

from flask_sqlalchemy import SQLAlchemy


db = SQLAlchemy()

from functools import wraps
from flask import Flask, render_template, url_for, redirect, request, session
import config
from sqlalchemy import or_,and_
from exts import db
from  models import User,Wenda,Comment

app = Flask(__name__)   # 创建Flask对象
app.config.from_object(config)  # 关联config.py文件进来

db.init_app(app)   # 建立和数据库的关系映射


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