PHP代码:
<?
/*
*名称：CnkknDPHPLoginClass
*描述：PHP用于登录的类，基于MySQL
*作者：DanielKing，cnkknd@163.com
*日期：2003/8/25
*/

classLogin
{
var$username;//用户名
var$userpass;//密码
var$userid;//用户id
var$userlevel;//用户级别

var$authtable="account";//验证用数据表

var$usecookie=true;//使用cookie保存sessionid
var$cookiepath='/';//cookie路径
var$cookietime=108000;//cookie有效时间

var$err_mysql="mysqlerror";//mysql出错提示
var$err_username="usernameinvalid";//用户名无效提示
var$err_user="userinvalid";//用户无效提示(被封禁)
var$err_password="passworderror";//密码错误提示

var$err;//出错提示

var$errorreport=false;//显示错误

functionLogin($dbserv,$dbport,$dbuser,$dbpass,$dbname)//构造函数,连接数据库
{
if(@mysql_pconnect($dbserv.":".$dbport,$dbuser,$dbpass))
{
mysql_select_db($dbname);
}
else
{
$this->errReport($this->err_mysql);
$this->err=$this->err_mysql;
}
}

functionisLoggedin()//判断是否登录
{
if(isset($_COOKIE['sid']))//如果cookie中保存有sid
{
session_id($_COOKIE['sid']);
session_start();
$this->username=$_SESSION['username'];
$this->userid=$_SESSION['userid'];
$this->userlevel=$_SESSION['userlevel'];
returntrue;
}
else//如果cookie中未保存sid,则直接检查session
{
session_start();
if(isset($_SESSION['username']))
returntrue;
}
returnfalse;
}

functionuserAuth($username,$userpass)//用户认证
{
$this->username=$username;
$this->userpass=$userpass;
$query="select*from`".$this->authtable."`where`username`='$username';";
$result=mysql_query($query);
if(mysql_num_rows($result)!=0)//找到此用户
{
$row=mysql_fetch_array($result);
if($row['bannd']==1)//此用户被封禁
{
$this->errReport($this->err_user);
$this->err=$this->err_user;
returnfalse;
}
elseif(md5($userpass)==$row['userpass'])//密码匹配
{
$this->userid=$row['id'];
$this->userlevel=$row['userlevel'];
returntrue;
}
else//密码不匹配
{
$this->errReport($this->err_password);
$this->err=$this->err_password;
returnfalse;
}
}
else//没有找到此用户
{
$this->errReport($this->err_username);
$this->err=$this->err_username;
returnfalse;
}
}

functionsetSession()//置session
{
$sid=uniqid('sid');//生成sid
session_id($sid);
session_start();
$_SESSION['username']=$this->username;//给session变量赋值
$_SESSION['userid']=$this->userid;//..
$_SESSION['userlevel']=$this->userlevel;//..
if($this->use_cookie)//如果使用cookie保存sid
{
if(!setcookie('sid',$sid,time()+$this->cookietime,$this->cookiepath))
$this->errReport("setcookiefailed");
}
else
setcookie('sid','',time()-3600);//清除cookie中的sid
}

functionuserLogout()//用户注销
{
session_start();
unset($_SESSION['username']);//清除session中的username
if(setcookie('sid','',time()-3600))
//清除cookie中的sid
returntrue;
else
returnfalse;
}

functionerrReport($str)//报错
{
if($this->error_report)
echo"ERROR:$str";
}
}
?>

mysql中表的结构


代码:
CREATETABLE`account`(
`id`bigint(20)NOTNULLauto_increment,
`username`varchar(255)NOTNULLdefault'',
`userpass`varchar(255)NOTNULLdefault'',
`banned`tinyint(1)NOTNULLdefault'0',
`userlevel`tinyint(4)NOTNULLdefault'0',
PRIMARYKEY(`id`)
)


使用一例


PHP代码:
<?
include"../myclasses/Login.php";
$dbserv="localhost";
$dbport="3306";
$dbuser="root";
$dbpass="123456";
$dbname="test";

$login=newLogin($dbserv,$dbport,$dbuser,$dbpass,$dbname);
$login->error_report=true;
$login->cookietime=3600*24*30;
if($login->isLoggedin())
{
echo$login->username."hasareadyloggedin";
}
elseif($login->userAuth("danielking","1234"))
{
echo"loginsuccessfully";
$login->setSession();
}

echo"<p>...</p>";


?>