1. 首页列表显示全部问答：
   1. 将数据库查询结果传递到前端页面 Question.query.all()
   2. 前端页面循环显示整个列表。
   3. 问答排序
2. 完成问答详情页布局：
   1. 包含问答的全部信息
   2. 评论区
   3. 以往评论列表显示区。
3. 在首页点击问答标题，链接到相应详情页。

 

from flask import Flask,render_template,request,redirect,url_for,session from flask_sqlalchemy import SQLAlchemy from functools import wraps from datetime import datetime import config,os app=Flask(__name__) app.config.from_object(config) db=SQLAlchemy(app) 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(20),nullable=False)     nickname = db.Column(db.String(20), nullable=True) class Question(db.Model):     __tablename__='wenda'     id=db.Column(db.Integer,primary_key=TabError,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')) # db.create_all()    #是否链接成功 # 数据添加 user=User(username='ma',password='gg') db.session.add(user) db.session.commit() # 数据查找 user = User.query.filter(User.username=='hh').first() user.password='gg' db.session.commit() # 数据查询 user = User.query.filter(User.username=='ma').first() print(user.username,user.password) # 数据删除 user = User.query.filter(User.username=='ma').first() db.session.delete(user) db.session.commit() # session会话连接 # filter()过滤器 # route制定路径和函数之间的关系 # def定义一个变量 @app.route('/') def switch():     return render_template('switch.html') def index():     context = {
          'question': Question.query.order_by('-creat_time').all()     }     return render_template('index.html',**context) @app.route('/detail/
    
     ') def detail(question_id):    return render_template('detail.html',ques = question_id) @app.route('/login/',methods=['GET','POST'])# 跳转登陆,methods定义它有两种请求方式 def login():     if request.method == 'GET':       return render_template('login.html')     else:         username = request.form.get('user')         password = request.form.get('psw')         user = User.query.filter(User.username == username).first()  # 判断用户名是否存在         if user:             if user.password==password:                 session['user'] = username                 session.permanent = True                 return   redirect(url_for('switch'))             else:                 return u'密码错误'         else:             return u'用户名不存在' @app.context_processor def mycontext():     username=session.get('user')     if username:         return {'username':username}     else:         return{} @app.route('/logout') def logout():     session.clear()     return  redirect(url_for('switch')) @app.route('/register/',methods=['GET','POST'])# 跳转注册,methods定义它有两种请求方式 def register():     if request.method == 'GET':         return render_template('register.html')     else:         username = request.form.get('user')         password = request.form.get('psw')         nickname = request.form.get('nickname')         user = User.query.filter(User.username == username).first() # 判断用户名是否存在         if user:             return u'该用户已存在'         else:             user = User(username=username,password=password,nickname=nickname)             db.session.add(user)             db.session.commit()             return redirect(url_for('login')) # 进入问答界面先登录功能 def loginFirst(func):     @wraps(func)     def wrapper(*args,**kwargs):         if session.get('user'):             return func(*args,**kwargs)         else:             return redirect(url_for('login'))     return wrapper @app.route('/wenda/',methods=['GET','POST']) @loginFirst def wenda():     if request.method=='GET':         return render_template('wenda.html')     else:         title=request.form.get('title')         detail=request.form.get('detail')         author_id = User.query.filter(User.username == session.get('user')).first().id         wenda = Question(title=title,detail=detail,author_id=author_id)         db.session.add(wenda)         db.session.commit()         return redirect(url_for('switch')) if __name__ == '__main__':     app.run(debug=True)