從首頁問答標題到問答詳情頁

2. 主PY文件寫視圖函數，帶id參數。 

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

3. 首頁標題的標籤作帶參數的連接。
         {{ url_for('detail',question_id = foo.id) }}
   
   
4. 在詳情頁將數據的顯示在恰當的位置。 

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

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

5. 創建評論的對象關係映射：

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

6.  嘗試實現發佈評論

   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(20),nullable=False)
       password = db.Column(db.String(20),nullable=False)
       userphone = 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'))
   
   db.create_all()
   
   @app.route('/')
   def zhuye():
       context={
           'questions': Question.query.all()
       }
       return render_template('zhuye.html',**context)
   
   
   
   @app.route('/detail/<question_id>')
   def detail(question_id):
       question = Question.query.filter(Question.id == question_id).first()
       return render_template('detail.html', question=question)
       return question_id
   
   
   
   @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:
               if user.password == password:
                   session['user'] = username
                   session.permanent = True
                   return redirect(url_for('zhuye'))
               else:
                   return '密碼錯誤！'
           else:
               return '不存在該用戶名！'
   
   
   @app.route('/zhuce/',methods=['GET','POST'])
   def zhuce():
       if request.method == 'GET':
           return render_template('zhuce.html')
       else:
           username = request.form.get('username')
           password = request.form.get('password')
           userphone = request.form.get('userphone')
           user = User.query.filter(User.username == username).first()
           if user:
               return 'username existed.'
           else:
               user1 = User(username=username, password=password, userphone=userphone,)
               db.session.add(user1)
               db.session.commit()
               return redirect(url_for('denglu'))
   
   #def loginFirst(func):
       #@wraps(func)
      # def wrapper(*args, **kwargs):
          # if session.get('user'):
               #return func(*args, **kwargs)
          # else:
              # return redirect(url_for('denglu'))
     #  return wrapper
   
   
   @app.route('/question/',methods=['GET','POST'])
   def question():
       if request.method == 'GET':
           return render_template('question.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)
           db.session.commit()
           return redirect(url_for('zhuye'))
   
   
   @app.route('/comment/',methods=['POST'])
   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('detail',question_id=question_id))
   
   
   
   @app.context_processor
   def mycontext():
       username=session.get('user')
       if username:
           return {'username':username}
       else:
           return {}
   @app.route('/logout/')
   def logout():
       session.clear()
       return redirect(url_for('zhuye'))
   
   if __name__ == '__main__':
       app.run(debug=True)

   {% extends 'base.html' %}
   
   {% block title %}Detail{% endblock %}
   
   {% block head %}
       <link href="{{ url_for('static',filename='css/detail.css') }}" rel="stylesheet" type="text/css">
   {% endblock %}
   
   {% block main %}
   <div class="detail" >
       <h2 align="center">title</h2>
       <a href="#">{{ question.author.username }}</a>
       <span>{{ question.creat_time }}</span>
       <div class="p">
           <p>{{ question.detail }}</p>
       </div>
       <form action="{{ url_for('comment') }}" method="post">
       <textarea name="detail" rows="10">請發表您的評論</textarea><br>
       <input name="question_id" type="hidden" value="{{question.id}}"/>
       <button >發表評論</button>
       </form>
       <br>
       <ul>
           <p style="font-weight: 600;font-size: 16.5px">Comment[{{ question.comments|length }}]</p>
           <div>
               {% for foo in question.comments %}
               <li>
                     <img src="{{ url_for('static',filename='image/xiaolian.png') }}">
                     <a href="#">{{ foo.author.username }}</a>
                     <span>{{ foo.creat_time }}</span><br>
                     <p>{{ foo.detail }}</p>
               </li>
               {% endfor %}
           </div>
       </ul>
   </div>
   {% endblock %}