php – 使用会话的高级用户身份验证

-those who are registered and are subscribed for current month
-those that are registered,but are not subscribed for current month
-users that are not registered (you cant be subscribed if you are not regitered)

我已经创建了识别这3种用户的代码并且行为恰当.我的问题是,这是要走的路吗？我以前从未做过类似的事情.或者我应该重新编程我的方法？

//login.PHP

//connect to database and see if a user and password combination exists. Store $exists=0 if not,and $exists=1 if it exists.
session_start();

$conn = new MysqLi($hn,$un,$pw,$db);
if ($conn->connect_error){
    die($conn->connect_error);
}
$query = "SELECT COUNT(1) as 'exists',expiration_date FROM table WHERE email = ? AND password = ?;";
$stmt = $conn->prepare($query);
$stmt->bind_param("ss",$email,$password);

$email = $_POST["email"];
$password = hash("hashingalgorithm","salt".$_POST["password"]."salthere");

$stmt->execute();
   /* Get the result */
$result = $stmt->get_result();
$num_of_rows = $result->num_rows;
$row = $result->fetch_assoc();
$exists = $row["exists"];
$expiration_date = $row["expiration_date"];

/* free results */
$stmt->free_result();

/* close statement */
$stmt->close();
$conn->close();

date_default_timezone_set('Europe/Berlin');


if ($exists==0){
    echo "Wrong email or password";
    $_SESSION['loginerror'] = 2;
    header('Location: https://www.homepage.com/login'); 
}else if ($exists){
    if (strtotime($expiration_date) < (strtotime("Now"))){//logged in,but not subscribed
        session_destroy();
        session_start();
        $_SESSION["authenticated"] = true;
        header('Location: https://www.homepage.com');
    }else{//logged in and ready to go
        $_SESSION["authenticated"] = true;
        $_SESSION["email"] = $email;
        header('Location: https://www.homepage.com');
    }
}else{
    echo "An error with has occured.";
}

然后在我网站的每一页上我都使用这段代码,看看有哪些用户访问过我

session_start();
if(isset($_SESSION["authenticated"]) && isset($_SESSION["email"])){ 
    $email = $_SESSION["email"];

    //connect to database and fetch expiration_date for a user with $email. Store it in $expiration_date

$conn = new MysqLi($hn,$db);
    if ($conn->connect_error){
        die($conn->connect_error);
    }
    $query = "SELECT expiration_date FROM table WHERE email = ?;";
    $stmt = $conn->prepare($query);
    $stmt->bind_param("s",$email);

    $email = $_SESSION["email"];
    $stmt->execute();
    /* Get the result */
    $result = $stmt->get_result();
    $num_of_rows = $result->num_rows;
    $row = $result->fetch_assoc();
    $expiration_date = $row["expiration_date"];
    /* free results */
    $stmt->free_result();
    /* close statement */
    $stmt->close();
    $conn->close();
    date_default_timezone_set('Europe/Berlin');

    if (strtotime($expiration_date) < (strtotime("Now"))){//logged in,but not subscribed
        session_destroy();
        session_start();
        $_SESSION["authenticated"] = true;
        header('Location: https://www.homepage.com');
    }else{  //html for subsribed and registered user
    echo <<<_END
    //html here
    _END;
    }
}else if(isset($_SESSION["authenticated"]) && !isset($_SESSION["email"])){
        // user is logged in,but not subscribed;
        echo <<<_END
        //htmlhere
        _END;
}else{// user is not registered nor is subscribed
        echo <<<_END
        //htmlhere
        _END;
}

代码有效,但我担心一旦用户注册并订阅,就会在每个页面上访问数据库.我实际上是在惩罚用户注册和订阅.
是否有更好的,性能明智的方式来处理这类问题？