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'))
    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'))

<div class="detail">
    <div class="detail_left">

    <h2>{{ question.title }}</h2>
    <a class="username">{{ question.author.username }}</a>
    <span class="badge">{{ question.creatTime }}</span>
    <hr>
    <a style="white-space: pre-wrap"  >{{ question.detail }}</a>
    <hr>
    <form action="{{ url_for('comment') }}" method="post">
    <textarea name='detail' class="form-control" rows="6" id="Detail"></textarea>
    <br><button class="btn-default">发布</button>
     </form>
    <p>评论：({{ question.comments|length }})</p>
    <ul class="comment">
        {% for foo in question.comments %}
        <span class="icon" aria-hidden="true"></span>
        <a href="#" class="name">{{ foo.author.username }}</a>
         <span class="badge2">{{ foo.creatTime }}</span>
           <br>
        <p class="neirong">{{ foo.detail }}</p>

        {% endfor %}
    </ul>


</div>
</div>
</body>