首页列表显示全部问答，完成问答详情页布局。

1. 首页列表显示全部问答：
   1. 将数据库查询结果传递到前端页面 Question.query.all()
   2. 前端页面循环显示整个列表。
   3. 问答排序
2. 完成问答详情页布局：
   1. 包含问答的全部信息
   2. 评论区
   3. 以往评论列表显示区。
3. 在首页点击问答标题，链接到相应详情页。

   from flask import Flask,render_template,request,redirect,url_for,session
   from flask_sqlalchemy import SQLAlchemy
   from functools import wraps
   import config
   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)
       nickname = db.Column(db.String(20))
   
   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)
       nickname = db.Column(db.String(20))
   
   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'))
   
   db.create_all()
   # user=User(username='mis1234',password='111111')
   # db.session.add(user)
   # db.session.commit()
   
   
   @app.route('/')
   def index():
       context={
           'questions': Question.query.all()
       }
       return render_template("index.html")
   
   
   @app.route('/login/', methods=['GET', 'POST'])
   def login():
       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('base'))
               else:
                   return '密码错误'
           else:
               return '用户名不存在'
   
   @app.route('/regist/', methods=['GET', 'POST'])
   def zhuce():
       if request.method == 'GET':
           return render_template("register.html")
       else:
           username = request.form.get('username')
           password = request.form.get('password')
           nickname = request.form.get('nickname')
           user = User.query.filter(User.username == username).first()
           if user:
               return '用户名已存在'
           else:
               user = User(username=username, password=password, nickname=nickname)
               db.session.add(user)  # 数据库，添加操作
               db.session.commit()
               return redirect(url_for('login'))
   
   # @app.context_processor
   # def mycontext():
   #     usern=session.get('user')
   #     if usern:
   #         return{'username':usern}
   #     else:
   #         return {}
   
   @app.route('/logout/')
   def logout():
       session.clear()
       return redirect(url_for('index'))
   
   
   def loginFirst(func):
       @wraps(func)
       def wrapper(*args,**kwargs):
           if session.get('user'):
               return func(*args,**kwargs)
           else:
               return redirect(url_for('login'))
       return wrapper
   
   
   @app.route('/fabu/',methods=['GET','POST'])
   @loginFirst
   def fabu():
       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)  # 数据库，添加操作
           db.session.commit()
       return redirect(url_for('base'))
   
   
   
   def fabu():
       return  render_template('question.html')
   
   if __name__=='__main__':
       app.run(debug=True)

   <!DOCTYPE html>
   <html lang="en">
   <head>
       <meta charset="UTF-8">
       <title>Title</title>
       <link rel="stylesheet" type="text/css" href="../static/css/details.css">
   </head>
   <body>
        <div>
            <h1>python,url_for</h1>
            <h3>mis1212</h3>
        </div>
        <div>
            <h2>python,url_for</h2>
        </div>
        <div >
             <lebal><input type="text"  width="200"></lebal><br>
             <input  class="one" type="button" name="发送" value="发送">
        </div>
   评论：
   <p class="inset">评论一</p>
   <p class="inset">评论二</p>
   <p class="inset">评论三</p>
   <p class="inset">评论四</p>
   </body>
   </html>