从首页问答标题到问答详情

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 User(db.Model):
    __tablename__ = 'user'
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    username = db.Column(db.String(20), nullable=False)
    password = db.Column(db.String(20), 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)
    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('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)
    creat_time = db.Column(db.DateTime, default=datetime.now)
    question = db.relationship('Question', backref=db.backref('comments',order_by=creat_time.desc))
    author = db.relationship('User', backref=db.backref('comments'))

detail

{% extends 'base.html' %}
{% block title %}
    问答详情页
{% endblock %}
{% block head %}
    <link type="text/css" rel="stylesheet" href="../static/css/detail.css">
{% endblock %}
<div class="detail">
    <h2>title</h2>
    <a href="#">username</a>
    <span>creat_time</span>
    <div class="p">
        <p>detail</p>
    </div>
    <textarea rows="5"></textarea><br>
    <button >发送</button>
    <br>


{% endblock %}