评论列表显示及排序，个人中心显示

1. 定义评论的视图函数
   @app.route('/comment/',methods=['POST'])
   def comment()：
   读取前端页面数据，保存到数据库中
2. 用<input type="hidden" 方法获取前端的"question_id" 
3. 显示评论次数
4. 要求评论前登录
5. 尝试实现详情页面下的评论列表显示
   1. 1.                                   
      2. py：

         from flask import Flask, render_template,request,redirect,url_for,session
         from flask_sqlalchemy import SQLAlchemy
         import config
         from functools import wraps
         from datetime import datetime
         
         app = Flask(__name__)
         app.config.from_object(config)
         db = SQLAlchemy(app)
         
         
         class User(db.Model):
             __tablename__ = 'User'
             id = db.Column(db.Integer, primary_key=True, autoincrement=True)
             username= db.Column(db.String(100), nullable=False)
             password= db.Column(db.String(500), nullable=False)
         
         
         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)
             creatTime = db.Column(db.DateTime,default=datetime.now)
             authorID = 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'))
             detail = db.Column(db.Text,nullable=False)
             creatTime = db.Column(db.DateTime,default=datetime.now)
             question = db.relationship('Question',backref=db.backref('comments',order_by=creatTime.desc))
             author = db.relationship('User',backref=db.backref('comments'))
         
         #db.create_all()
         
         @app.route('/')
         def shouye():
             context={
                 'questions': Question.query.all()
             }
             return render_template('shouye.html',**context)
         
         @app.route('/detail/<question_id>')
         def question_detail(question_id):
             question = Question.query.filter(Question.id == question_id).first()
             return render_template('detail.html',question=question)
         
         @app.route('/zhuce/',methods=['GET','POST'])
         def zhuce():
             if request.method == 'GET':
                 return render_template('zhuce.html')
             else:
                 username = request.form.get('username')  # 获取form中的数据
                 password = request.form.get('password')  # 获取form中的数据
                 email = request.form.get('email')  # 获取form中的数据
                 user = User.query.filter(User.username == username).first()
                 if user:
                     return'用户已存在'
                 else:
                     user = User(username = username,password=password)
                     db.session.add(user)
                     db.session.commit()
                     return redirect(url_for('denglu'))
         
         
         
         
         @app.route('/denglu/',methods=['GET','POST'])
         def denglu():
             if request.method=='GET':
                 return render_template('denglu.html')
             else:
                 username = request.form.get('username')
                 password = request.form.get('password')
         
                 user=User.query.filter(User.username==username).first()
         
                 if user:
                     session['user']=username
                     session.permanent=True
                     if user.password==password:
                         return redirect(url_for('shouye'))
                     else:
                         return '密码错误'
                 else:
                     return '此用户不存在'
         
         @app.context_processor
         def mycontext():
             usern=session.get('user')
             if usern:
                 return {'username':usern}
             else:
                 return{}
         
         @app.route('/logout/')
         def logout():
             session.clear()
             return redirect(url_for('shouye'))
         
         def login_re(func): #参数是函数
             @wraps(func)
             def wrapper(*args, ** kwargs): #定义个函数将其返回
                 if session.get('user'):
                     return func(*args,**kwargs)
                 else:
                     return redirect(url_for('denglu'))
             return wrapper #返回一个函数
         
         
         @app.route('/question/',methods=['GET','POST'])
         @login_re
         def question():
             if request.method == 'GET':
                 return render_template('question.html')
             else:
                 title = request.form.get('title')
                 detail = request.form.get('detail')
                 authorID = User.query.filter(User.username == session.get('user')).first().id
                 question = Question(title=title,detail=detail,authorID=authorID)
                 db.session.add(question)
                 db.session.commit()
                 return redirect(url_for(('shouye')))
         
         @app.route('/comment/',methods=['GET','POST'])
         @login_re
         def comment():
             detail = request.form.get('detail')
             author_id = User.query.filter(User.username == session.get('user')).first().id
             question_id = request.form.get('question_id')
             comment = Comment(author_id=author_id,question_id=question_id,detail=detail)
             db.session.add(comment)
             db.session.commit()
             return redirect(url_for('question_detail',question_id=question_id))
         
         
         @app.route('/self/<user_id>')
         def self(user_id):
             user = User.query.filter(User.id==user_id).first()
             context={
                 'user':user
         
             }
             return render_template('self.html',**context)
         
         if __name__ == '__main__':
             app.run(debug=True)

         html：

         {% extends'ba.html' %}
         {% block title %}
         
         {% endblock %}
         {% block head %}
             <link rel="stylesheet" href="{{ url_for('static',filename='css/self.css')}}" type="text/css">
         {% endblock %}
         {% block main %}
         <body>
         
         <div class="detail">
             <h2>{{ user.username }}</h2>
             <div class="all questions">
                 <p class="p">全部问答</p>
                 <div class="detail_left">
                     {% for foo in user.question %}
                         <span class="icon2" aria-hidden="true"></span>
                         <a href="#" class="name">{{ foo.author.username }}</a>
                         <span class="badge">{{ foo.creatTime }}</span>
                         <br>
                         <p class="title">{{ foo.title }}</p>
                         <p class="wenzhang" >{{ foo.detail }}</p>
                        <div style="border-top:1px dashed black;height: 1px;overflow:hidden"></div>
                     {% endfor %}
         
                 </div>
             </div>
         <div class="all comments">
                 <p class="p">全部评论</p>
                 <div class="detail_left">
                     {% for foo in user.comments %}
                         <span class="icon2" aria-hidden="true"></span>
                         <a href="#" class="name">{{ foo.author.username }}</a>
                         <span class="badge">{{ foo.creatTime }}</span>
                         <br>
                         <p class="neirong">{{ foo.detail }}</p>
                         <div style="border-top:1px dashed black;height: 1px;overflow:hidden"></div>
                     {% endfor %}
                 </div>
         </div>
         <div class="self">
                 <p class="p">个人信息</p>
                 <div class="detail_left">
                     <li>用户名：{{ user.username }}</li>
                     <div style="border-top:1px dashed black;height: 1px;overflow:hidden"></div>
                     <li>编号：{{ user.id }}</li>
                     <div style="border-top:1px dashed black;height: 1px;overflow:hidden"></div>
                     <li>文章篇数：{{ user.question|length }}</li>
                     <div style="border-top:1px dashed black;height: 1px;overflow:hidden"></div>
                 </div>
             </div>
         </div>
         </body>
         {% endblock %}