如何设计一个支持题目共享和交流的在线答题平台

from flask import Flask, request, render_template, redirect, url_for
from flask_sqlalchemy import SQLAlchemy

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///question.db'
db = SQLAlchemy(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(50), unique=True, nullable=False)
    password = db.Column(db.String(50), nullable=False)
    email = db.Column(db.String(50), unique=True, nullable=False)

    def __repr__(self):
        return '<User %r>' % self.username

class Question(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    type = db.Column(db.String(50), nullable=False)
    content = db.Column(db.Text, nullable=False)
    options = db.Column(db.Text, nullable=False)
    answer = db.Column(db.String(50), nullable=False)
    user_id = db.Column(db.Integer, db.ForeignKey('user.id'))

    def __repr__(self):
        return '<Question %r>' % self.id

@app.route('/')
def index():
    questions = Question.query.all()
    return render_template('index.html', questions=questions)

@app.route('/question/<question_id>')
def question_detail(question_id):
    question = Question.query.get(question_id)
    return render_template('question_detail.html', question=question)

@app.route('/login', methods=['GET', 'POST'])
def login():
    if request.method == 'POST':
        username = request.form['username']
        password = request.form['password']
        user = User.query.filter_by(username=username, password=password).first()
        if user:
            return redirect(url_for('index'))
        else:
            return render_template('login.html', error='登录失败，请检查用户名和密码。')
    return render_template('login.html')

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