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。

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

<a href="{{ url_for('detail',question_id=foo.id) }}">{{ foo.title }}</a>

<div class="page-header">
        <h3>Title{{ ques }}<br>
            <small>author {{ ques.author_id }}{{ ques.creat_time }}</small>
        </h3>
    </div>
    <p class="lead">detail{{ ques.detail }}</p>
    <hr>
    <form action="{{ url_for('question') }}" method="post">
    <div class="form-group">
        <textarea name="new_comment" class="form-control" rows="3" id="new_comment" placeholder="write your comment"></textarea>
        <input type="hidden" name="question_id" value="{{ ques.id }}">
    </div>
    <button type="submit" class="btn btn-default">发送</button>
    </form>
    <h4>评论：({{ ques.comments|length }})</h4>
    <ul class="list-group" style="margin: 10px"></ul>

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