11 实现用户登录

1.流程图

2.加密

注意：需要对密码进行加密
如果使用md5加密，则密码包含32个字符
如果使用sha1加密，则密码包含40个字符，推荐使用这种方式

3.创建表

mysql> create table users(
    -> id int auto_increment primary key not null,
    -> name varchar(20),
    -> passwd char(40));

加入测试数据

插入如下数据，用户名为abc,密码为123,这是sha1加密后的值

mysql> insert into users values(0,'abc','40bd001563085fc35165329ea1ff5c5ecbdbbeef')；

4.程序

　　1）版本1：框架

#-*- coding:utf-8 -*-
from MysqlHelper import MysqlHelper

#获取用户输入
user_name = raw_input("请输入用户名:")
passwd = raw_input("请输入密码:")

# 匹配数据库
login = MysqlHelper('localhost',3306,'root','mysql','py31')
sql = 'select %s from users where name=%s'
result = login.all(sql,[passwd,user_name])
print(result)


#判断正确错误

　　2）版本2：判断用户名错误

#-*- coding:utf-8 -*-
from MysqlHelper import MysqlHelper

#获取用户输入
user_name = raw_input("请输入用户名:")
passwd = raw_input("请输入密码:")

# 匹配数据库
login = MysqlHelper('localhost',3306,'root','mysql','py31')
sql = 'select %s from users where name=%s'
result = login.all(sql,[passwd,user_name])
print(result)
#((u'123',),)

#判断正确错误

if len(result) == 0:
    print("用户名错误")

　　3）版本3：加密

# hashlib 包源码

     >>> import hashlib
     >>> m = hashlib.md5()
     >>> m.update("Nobody inspects")
     >>> m.update(" the spammish repetition")
     >>> m.digest()
     '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'
 
 More condensed:
 
     >>> hashlib.sha224("Nobody inspects the spammish repetition").hexdigest()
     'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

password = sha1()
password.update(passwd)
password = password.hexdigest()
print(password)

　　4）版本4：判断

#-*- coding:utf-8 -*-
from MysqlHelper import MysqlHelper
from hashlib import sha1


#获取用户输入
user_name = raw_input("请输入用户名:")
passwd = raw_input("请输入密码:")

#     >>> import hashlib
#     >>> m = hashlib.md5()
#     >>> m.update("Nobody inspects")
#     >>> m.update(" the spammish repetition")
#     >>> m.digest()
#     '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9'
#
# More condensed:
#
#     >>> hashlib.sha224("Nobody inspects the spammish repetition").hexdigest()
#     'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2'

#对密码加密
password = sha1()
password.update(passwd)
password = password.hexdigest()
print(password)

# 匹配数据库
login = MysqlHelper('localhost',3306,'root','mysql','py31')
sql = 'select passwd from users where name=%s'
result = login.all(sql,[user_name])
print(result)
#((u'123',),)
#print(result[0][0]) for test

#判断正确错误

if len(result) == 0:
    print("用户名错误")
elif result[0][0] == password:

    print("登陆成功")
else:
    print("密码错误")

5.老师版本

#encoding=utf-8
from MysqlHelper import MysqlHelper
from hashlib import sha1

sname=raw_input("请输入用户名：")
spwd=raw_input("请输入密码:")

s1=sha1()
s1.update(spwd)
spwdSha1=s1.hexdigest()

sql="select upwd from userinfos where uname=%s"
params=[sname]

sqlhelper=MysqlHelper('localhost',3306,'test1','root','mysql')
userinfo=sqlhelper.get_one(sql,params)
if userinfo==None:
    print '用户名错误'
elif userinfo[0]==spwdSha1:
    print '登录成功'
else:
    print '密码错误'