从首页问答标题到问答详情页

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)

首页标题的标签做带参数的链接。
{{ url_for('detail',question_id = foo.id) }}

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(100), nullable=False)
    password= db.Column(db.String(500), 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)
    create_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'))
    create_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'))

db.create_all()


@app.route('/')
def hello_world():
    return render_template('base.html')
@app.route('/zhuce/',methods=['GET','POST'])

def zhuce():
    if request.method == 'GET':
        return render_template('zc.html')
    else:
        username = request.form.get('username')  # 获取form中的数据
        password = request.form.get('password')  # 获取form中的数据
        # email = request.form.get('email')  # 获取form中的数据
        user = User.query.filter(User.username ==username).first()
        if user:
            return'用户已存在'
        else:
            user = User(username = username,password=password)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for('denglu'))

@app.route('/denglu/',methods=['GET','POST'])
def denglu():
    if request.method=='GET':
        return render_template('dl.html')
    else:
        username = request.form.get('username')
        password = request.form.get('password')

        user=User.query.filter(User.username==username).first()
        #判断用户名是否存在
        if user:
            session['user']=username
            session.permanent=True
            if user.password==password:
                return redirect(url_for('shouye'))
            else:
                return '密码错误'
        else:
            return '此用户不存在'

@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('shouye'))

def log(func): #参数是函数
    @wraps(func)
    def wrappers(*args,** kwargs): #定义个函数将其返回
        if session.get('user'):
            return func(*args,**kwargs)
        else:
            return redirect(url_for('denglu'))
    return wrappers #返回一个函数


@app.route('/shouye/')
def shouye():
    context = {
        'questions':Question.query.order_by('create_time').all()
    }
    return render_template('hh.html',**context)

@app.route('/wenda/',methods=['GET','POST'])
@log
def wenda():
    if request.method=='GET':
        return render_template('wd.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)#保存到数据库
        db.session.commit()#提交
    return redirect(url_for('shouye'))#跳转

@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)

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

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 }}
建立评论的对象关系映射：

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

尝试实现发布评论。

{% extends 'base.html' %}
{% block title %}
    问答详情
{% endblock %}
{% block main %}
    <div class="box">
        <h3 href="#" >{{ ques.title }}</h3><small> {{ ques.author.username }}<span class="badge" style="margin-left: 75%">{{ ques.create_time }}</span></small>
        <hr>
        <p>{{ ques.detail }}</p>
        <hr>
        <form>
            <div><textarea class="form-control" id="comment" rows="3" style="margin-left: 1%" name="comment" placeholder="write your comment"></textarea><br></div>
            <button type="submit" >发送</button>
        </form>
      <h4>评论:</h4>
         <ul class="list-group">
                <li class="list-group-item">
                    <img style=" 30px" src="{{ url_for('static',filename='css/touxiang.jpg') }}" alt="64">
                    <a href="#"></a><br>
                    <p style="align-content: center"></p>
                    <span class="badge" style="margin-left: 60%"></span>
                    <p style="margin-left: 25%"></p><br>
                </li>
        </ul>

    </div>
{% endblock %}