評論列表顯示及排序，我的中心顯示

1. 顯示全部評論
   {% for foo in ques.comments %}
   
   
2. 全部評論排序
   uquestion = db.relationship('Question', backref=db.backref('comments', order_by=creat_time.desc))
   
   
3. 顯示評論條數
   {{ ques.comments|length }}
   
   
4. 完成我的中心

1.我的中心的頁面佈局（html文件及相應的樣式文件）

2.定義視圖函數def usercenter(user_id):

3.向前端頁面傳遞參數

4.頁面顯示相應數據

發佈的所有問答

發佈的所有評論

我的信息

5.各個頁面連接到我的中心

py

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):
    __table__name = '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(50))

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'))  # 外鍵
    question_id = db.Column(db.Integer, db.ForeignKey('question.id'))  # 外鍵
    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 index():
    context = {
        'question': Question.query.all()
    }
    # question : Question.query.all()
    return render_template('index.html', **context)

@app.route('/regist/',methods=['GET','POST'])
def regist():
    if request.method=='GET':
        return render_template('regist.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 u'username existed'
        else:
            user=User (username=username,password=password,nickname=nickname)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('login'))


@app.route('/login/',methods=['GET','POST'])
def login():
    if request.method=='GET':
        return render_template('login.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
                return redirect(url_for('index'))
            else:
                return u'password error'
        else:
            return u'username is not existed'



@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('/lable/',methods=['GET','POST'])
@loginFirst
def lable():
    if request.method == 'GET':
        return render_template('lable.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('index'))

@app.route('/detail/<question_id>')
def detail(question_id):
    # context={
    #     'comments':Comment.query.all()
    # }
    quest = Question.query.filter(Question.id == question_id).first()
    return render_template('detail.html',ques=quest)

@app.route('/comment/', methods=['POST'])
@loginFirst
def comment():
        comment= request.form.get('commentdetail')
        ques_id=request.form.get('question_id')
        auth_id=User.query.filter(User.username==session.get('user')).first().id
        comm=Comment(author_id=auth_id,question_id=ques_id,detail=comment)
        # question.author=User
        db.session.add(comm)  # 數據庫，添加操做
        db.session.commit() #提交
        return redirect(url_for('detail', question_id=ques_id))

@app.route('/usercenter/<user_id>')
@loginFirst
def usercenter(user_id):
    user=User.query.filter(User.id==user_id).first()
    context={
        'username':user.username,
        'questions':user.question,
        'comments':user.comments
    }
    return render_template('usercenter.html', ques=user)

if __name__ == '__main__':
    app.run(debug=True)

usercenter.html

{% extends 'base.html' %}
{% block title %}我的中心{% endblock %}
{% block head %}
    <link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='css/usercenter.css') }}">
{% endblock %}
{% block main %}
    <div class="a1">
        <h3>{{ username }}<br>
            <small>所有問答</small>
        </h3></div>
        <ul>
            {% for foo in ques.question %}
                <li class="list-group-item" >
                <a href="#">{{ foo.author.username }} </a><br>
                    <a href={{ url_for('detail',question_id=foo_id)}}>{{ foo.title }}</a>

                    <span class="badge">{{ foo.creat_time }}</span>
                    <p class="abstract">{{ foo.detail }}</p>
                </li>
        {% endfor %}

    <div class="a1">
        <h3>{{ username }}<br>
            <small>所有評論</small>
        </h3></div>
        <ul>
            {% for foo in ques.comments %}
                <li class="list-group-item" >
                <a href="#">{{ foo.author.username }} </a><br>
                    <a href={{ url_for('detail',question_id=foo_id)}}>{{ foo.title }}</a>

                    <span class="badge">{{ foo.creat_time }}</span>
                    <p class="abstract">{{ foo.detail }}</p>
                </li>
        {% endfor %}

    <div class="a1">
        <h3>{{ username}}<br>
            <small>我的信息</small>
        </h3></div>
        <ul>
            <li>用戶：{{ username}}</li>
            <li>文章篇數：</li>

        </ul>



{% endblock %}