从首页问答标题到问答详情页

1. 主PY文件写视图函数，带id参数。 

   @app.route('/detail/<question_id>')
   def detail(question_id):
       quest = 
       return render_template('detail.html', ques = quest) 

2. 首页标题的标签做带参数的链接。
         {{ url_for('detail',question_id = foo.id) }}
   
   
3. 在详情页将数据的显示在恰当的位置。 

   {{ ques.title}}
   {{ ques.id  }}{{  ques.creat_time }}

   {{ ques.author.username }} 
   {{ ques.detail }}

4. 建立评论的对象关系映射：

   class Comment(db.Model):
       __tablename__='comment'

5.  尝试实现发布评论。

   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'))
       create_time = db.Column(db.DateTime, default=datetime.now)
       detail = db.Column(db.Text, nullable=False)
       question = db.relationship('Question', backref=db.backref('comment'))
       author = db.relationship('User', backref=db.backref('comment'))

   @app.route('/sywdxq/<question_id>')
   def sywdxq(question_id):
       quest = Question.query.filter(Question.id == question_id).first()
       return render_template("sywdxq.html",ques=quest)
   
   def loginFirst(func):
       #行动前需要登录，定义装饰器
       @wraps(func)
       def wrapper(*args,**kwargs):
           if session.get('user'):
               return func(*args,**kwargs)
           else:
               return redirect(url_for('login'))
       return wrapper
   
   
   @app.route('/sywdxq',methods=['GET','POST'])
   @loginFirst
   def sywdxq():
       if request.method=='GET':
           return render_template('sywenda.html')
       else:
           title=request.form.get('title')
           detail=request.form.get('detail')
           author_id=User.query.filter(User.username==session.get('user')).first().id
           question = Question(title=title,detail=detail,author_id=author_id)
           db.session.add(question)  # 数据库，添加操作
           db.session.commit()
           return redirect(url_for('sywdxq'))

     <div class="page-headr">
               <h1>welcome !!!</h1><br>
   
               <h3>Title:{{ ques.title }}<br>
                   <small class="ss" >author:{{ ques.author.username }}
                       <br><span class="badge">发布时间:{{ ques.creat_time }}</span></small>
               </h3>
               <hr>
               <p>detail:{{ ques.detail }}</p>
               <hr>
                <form action="{{url_for('comment')}}" method="post" style="">
                   <div class="form-group">
   
               <textarea name="new_comment" class="form-control" rows="5" id="new-comment"
                         placeholder="write your comments" style="width: 800px"></textarea><br>
                   </div>
                   <button type="submit" class="btn btn-default" style="width:100px "> 发送
                   </button>
               </form>
   {#                            <h4>comment:({{ ques.comments|length }})</h4>#}
               <ul class="list-group" style="margin: 10px"></ul>
           </div>
       </div>
   
       <div class="col-md-2 column "></div>
   
   {% endblock %}