完成注册功能

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

app = Flask(__name__)
app.config.from_object(config)

db=SQLAlchemy(app)

class User(db.Model):
    __tablename__=‘users‘
    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))

#db.create_all()

#查
#user = User.query.filter(User.username == ‘sk‘).first()
#print(user.id,user.password)

#改
#user = User.query.filter(User.username == ‘mis1234‘).first()
#user.password=‘888888‘
#user.username=‘sk‘
#db.session.commit()
#print(user.id,user.password)

#删
#user = User.query.filter(User.username==‘sk‘).first()
#db.session.delete(user)
#db.session.commit()


#增
#user = User(username=‘mis1234‘,password=‘111111‘)
#db.session.add(user)
#db.session.commit()

@app.route(‘/‘)
def index():
    return  render_template(‘base.html‘)
@app.route(‘/login/‘)
def login():
    return render_template(‘login.html‘)
@app.route(‘/register/‘,methods=[‘GET‘,‘POST‘])
def register():
    if request.method==‘GET‘:
        return render_template(‘register.html‘)
    else:
        usern = request.form.get(‘username‘)
        nickn = request.form.get(‘nickname‘)
        passw = request.form.get(‘password‘)
        user = User.query.filter(User.username == usern).first()
        if user:
            return ‘username existed.‘
        else:
            user1 = User(username = usern,password = passw,nickname = nickn)
            db.session.add(user1)
            db.session.commit()
            return redirect(url_for(‘login‘))

@app.route(‘/question‘)
def question():
    return render_template(‘question.html‘)


if __name__ == ‘__main__‘:
    app.run()

{% extends‘base.html‘ %}

{% block title %}
注册
{% endblock %}
{% block head %}
    <link rel="stylesheet" type="text/css" href="{{ url_for(‘static‘,filename=‘css/js24.css‘) }}">
    <script src="{{ url_for(‘static‘,filename=‘js/js24.js‘) }}"></script>
{% endblock %}
{% block main %}
<div class="bg-img">
    <div class="box">
        <h1>注册</h1>
        <div class="input_box">
            <form action="{{ url_for(‘register‘) }}" method="post">
            用户名：<input id="username" type="text" placeholder="请输入新用户名" name="username">
        </div>
        <br>
        <div class="input_box">
            昵称：&nbsp<input id="nickname" type="text" placeholder="请输入昵称" name="nickname">
        </div>
        <br>
        <div class="input_box">
            密 码：&nbsp&nbsp<input id="userpass" type="password" placeholder="请输入新密码" name="password">
        </div>
        <br>
        <div class="input_box">
            密 码：&nbsp&nbsp<input id="reuserpass" type="password" placeholder="请再次输入新密码">
        </div>
        <br>
        <div class="link_box">
            <a href="{{ url_for(‘login‘) }}">
                已有帐号，立即登陆
                <b> ></b>
            </a>
        </div>
        <div id="error_box"><br></div>
        <div class="input_box">
           <button id="button" onclick="return fnRegister()">注册</button>

        </div>
        </form>
    </div>
</div>

{% endblock %}

function fnRegister() {
    var oUsername = document.getElementById("username");
    var oUserpass = document.getElementById("userpass");
    var oError = document.getElementById("error_box");
    oError.innerHTML="<br>";

    if(oUsername.value.length >20 || oUsername.value.length <6){
        oError.innerHTML = "用户名6到20位";
        return false;
    }
    else if ((oUsername.value.charCodeAt(0) >= 48) && oUsername.value.charCodeAt(0) <= 57) {
        oError.innerHTML = "不能以数字开头";
        return false;
    }
    else for (var i = 0; i < oUsername.value.length; i++) {
            if ((oUsername.value.charCodeAt(i) < 48 || oUsername.value.charCodeAt(i) > 57) && (oUsername.value.charCodeAt(i) < 97 || oUsername.value.charCodeAt(i) > 122)) {
                oError.innerHTML = "only letter or name.";
                return false;
            }
        }
    if(oUserpass.value.length>20 || oUserpass.value.length<6){
        oError.innerHTML = "密码6到20位";
        return false;
    }
    else if ((oUserpass.value.charCodeAt(0) >= 48) && oUserpass.value.charCodeAt(0) <= 57){
        oError.innerHTML = "不能以数字开头";
        return false;
    }
    if(document.getElementById("userpass").value!=document.getElementById("reuserpass").value){
        oError.innerHTML = "密码不一致，请重新输入密码";
        return false;
    }
return true;
    //window.alert("注册成功！立即登录")
}