登录功能完成：

1.js:设置return

function fnLogin() {

var oUname=document.getElementById("uname");

var oUpass=document.getElementById("upass");

var oError=document.getElementById("error_box");

var isError=true;

oError.innerHTML="
"

//uname

if ((oUname.value.length < 6) || (oUname.value.length > 20)) {

oError.innerHTML = "用户名要6-20位";

isError=false;

return isError;

}else if ((oUname.value.charCodeAt(0)>=48)&&(oUname.value.charCodeAt(0)<=57)){

oError.innerHTML="首字母必须是字母";

isError=false;

return isError;

}else {

for(var i=0;i

if ((oUname.value.charCodeAt(i)<48)||(oUname.value.charCodeAt(i)>57)&&(oUname.value.charCodeAt(i)<97) ||(oUname.value.charCodeAt(i)>122)){

oError.innerHTML="用户名只能是字母和数字";

isNotError=false;

return isError;

}

}

}

//upass

if ((oUpass.value.length < 6 )|| (oUpass.value.length > 20)) {

oError.innerHTML = "密码要6-20位";

isError=false;

return isError;

}

return isError;

window.alert("登录成功！")

}

2.html:设置

form

input{% extends'base.html' %}

{% block title %}登录{% endblock %}

{% block head %}

{% endblock %}

{% block main %}

{% endblock %}

3.py:

@app.route设置methods

GET

POST读取表单数据

查询数据库用户名密码对：记住用户名

跳转到首页

用户名密码不对：提示相应错误。from flask import Flask, render_template, request, redirect, url_for, session

from flask_sqlalchemy import SQLAlchemy

import config

app=Flask(__name__)

app.config.from_object(config)

db=SQLAlchemy(app)

# 创建用户模型

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(50))

# db.create_all()

# 首页

@app.route('/')

def index():

return render_template('base.html')

#登录

@app.route('/login/',methods={'GET','POST'})

def login():

if request.method=='GET':

return render_template('login.html')

else:

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

password = request.form.get('password')

nickname = request.form.get('nickname')

user = User.query.filter(User.username == username).first()

if user:

if user.password==password:

session['user'] = username

session.permanent=True

return redirect(url_for('index')) # 返回到首页

else:

return u'error username or password' #输出错误

#注册

@app.route('/enroll/',methods={'GET','POST'})

def enroll():

if request.method=='GET':

return render_template('enroll.html')

else:

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

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)#数据库操作

db.session.commit()

return redirect(url_for('login'))# 重定向到登录页

#提问

@app.route('/questions/')

def questions():

return render_template('questions.html')

if __name__ == '__main__':

app.run(debug=True)

session：

从`flask`中导入`session`

设置`SECRET_KEY`

操作字典一样操作`session`：增加用户名`session['username']=`usernameimport os

SECRET_KEY = os.urandom(24)

SQLALCHEMY_DATABASE_URI = 'mysql+pymysql://root:@127.0.0.1:3306/mis_db?charset=utf8'

SQLALCHEMY_TRACK_MODIFICATIONS = False

1.网页运行结果：

成功运行跳转到首页：

2.数据库运行结果：

来源：https://www.cnblogs.com/iamzhuangyuan/p/7871801.html