完成注册功能

js文件： onclick函数return True时才提交表单，return False时不提交表单。

function fnLogin() {
    var oUname = document.getElementById("name");
    var oError = document.getElementById("error_box");
    var oUpass = document.getElementById("password");
    var oCheckpass = document.getElementById("password2");
    
    var isError =true;
    if(oUname.value.length<6||oUname.value.length>20){
        oError.innerHTML="用户名长度为6到12位";
        return false;
    }else if(oUname.value.charCodeAt(0)>=48&&oUname.value.charCodeAt(0)<=57){
        oError.innerHTML="用户名不能以数字开头";
        return false;
    }else for(var i=0;i<oUname.value.length;i++){
        if((oUname.value.charCodeAt(i)<48||oUname.value.charCodeAt(i)>57)&&(oUname.value.charCodeAt(i)<97||oUname.value.charCodeAt(i)>122)){
        oError.innerHTML="用户名只能包含数字，小写字母";
        return false;
        }
    }

    if(oUpass.value.length<6||oUpass.value.length>20){
        oError.innerHTML="密码长度为6-20位";
        return false;
    }

    if(oCheckpass.value!=oUpass.value) {
        oError.innerHTML = "密码不一致,重新输入你的密码";
        return false;
    }

    window.alert("注册成功");
    return true;
}

html文件：

<form>中设置 action和method="post"

<input> 中设置 name

{% extends'base.html' %}
{% block title %}
    注册
{% endblock %}
    {% block head %}
    <link href="../static/css/hh.css" rel="stylesheet" type="text/css">
    <script src="../static/js/zc.js"></script>
{% endblock %}
{% block main %}
<body><br><br><br>
  <div><h1>武林|注册</h1></div>
    <div class="box">
         <form action="{{ url_for('regist') }}" method="post" >
        <div class="input_box">
              请输入账号：<input id="name" name="username"type="text"placeholder="请输入用户名"><br>

        </div>
        <br>
        <div class="input_box">
          请输入密码：<input id="password" name="password"type="password"placeholder="请输入密码"><br><br>
          请确认密码：<input id="password2" name="password2"type="password"placeholder="请再次输入密码"><br>
        </div>
        <br>
        <div id="error_box"><br></div>
        <div class="input_box">
            <button onclick="fnLogin()">注册</button>

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

</div>
</body>
{% endblock %}
</html>

主py文件中：
1. from flask import request, redirect, url_for
2. @app.route('/regist/', methods=['GET', 'POST’])

def regist():

if request.method == 'GET':

return render_template('regist.html')

else:

username = request.form.get(‘username’)#获取form中的数据

判断用户名是否存在:存在报错

不存在，存到数据库中

redirect重定向到登录页

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

import config

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))
# db.create_all()
''' 
    user=User(username='hehe',password='1234567')
    db.session.add(user)
    db.session.commit()
'''
@app.route('/')
def hh():
    return render_template('hh.html')


@app.route('/login/')
def login():
    return render_template("dl.html")


@app.route('/regist/',methods=['GET','POST'])
def regist():
    if request.method=='GET':
        return render_template("zc.html")
    else:
        username = request.form.get("username")
        password = request.form.get("password")
        user = User.query.filter(User.username == username).first()
        if user:
            return ' 用户名已存在'
        else:
            user = User(username=username, password=password)
            db.session.add(user)#数据库，添加操作
            db.session.commit()
            return redirect(url_for('login'))

@app.route('/wenda/')
def wenda():
    return render_template("wenda.html")


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