会话控制 -（一）COOKIE/SESSION

COOKIE/SESSION原理：

作业：独立完成新用户注册的过程 ,并详细会话的完整流程,以及注意事项

<?php
//根据用户操作，给出不同响应
//登录、注册、退出
$dbConfig =[
    'type'=>'mysql',
    'host' => 'localhost',
    'dbname' => 'testsql',
    'port'=>'3306',
    'charset'=>'utf8',
    'username' => 'zolo',
    'password' => '123456'
    ];
 //import variables into the current symbol table from an array
extract($dbConfig);
$db = new PDO("$type:host=$host;port=$port;dbname=$dbname;charset=$charset",$username,$password);
$sqlquery = "select * from `user`"; 
$stmt = $db->prepare($sqlquery);
$stmt ->execute();
$res = $stmt->fetchAll(PDO::FETCH_ASSOC);
// foreach($res as $user){
//     printf('<pre>%s</pre>',print_r($user,true));}
session_start();
$method = $_GET['action'];
switch(strtolower($method)){
    case 'login':
        if($_SERVER['REQUEST_METHOD']=='POST'){
            extract($_POST);
            //echo "登录信息是：".$username.'<br>';
            array_filter($res,function($user) use ($name,$password){
                if($user['name'] == $name && $user['password'] == $password){
                    $_SESSION['name']= $name;
                    exit('<script>alert("登录成功");location.href="home.php"</script>');
                }else{
                    exit('<script>alert("用户名或密码错误");location.href="login.php"</script>');
                }
            });
        }else{
            echo '登录错误';
        }
    break;
    case 'register':
        if($_SERVER['REQUEST_METHOD']=='POST'){
            extract($_POST);
            if($password == $confirpsw){
                array_filter($res,function($user) use ($name,$password,$db){
                    if($user['name'] == $name){
                        //$_SESSION['name']= $name;
                        exit('<script>alert("用户已存在,请登录");location.href="login.php"</script>');
                    }else{
                        if($name && $password){
                        $sql = 'INSERT `user` SET `name` = ?,`password`= ?'; 
                        $stmt = $db->prepare($sql);
                        $stmt ->execute([$name,$password]);
                        $_SESSION['name']= $name;
                        exit('<script>alert("恭喜，注册成功");location.href="home.php"</script>');
                        }else{
                            exit('<script>alert("非法数据");location.href="register.php"</script>');
                        }
                    }
                });
            }else{
            exit('<script>alert("两次输入密码不一致");location.href="register.php"</script>');
            }
        }
    break;
    case 'logout':
        echo '设置session.name为空';
        session_unset();
        exit('<script>alert("退出成功");location.assign("home.php")</script>');
    break;
}

代码流程图