在PHP中设置会话

我似乎不明白如何设置会话。我写了这段代码：

<?php
require_once '../database/Database.php';
session_start();
$database = new Database('localhost', 'root', '');


if(isset($_POST['login'])){
    $username = $_POST['username'];
    $password = $_POST['password'];
    if($database->login($username, $password)){
        $loggedIn = $_SESSION['loggedIn'] = true; 
        header("location: ../dashboard/dashboard.php");
    }
    else{
        echo "You've failed to login";
    }
}
?>
<h2><!--<a href="../index.php" role="button" class="btn btn-info btn-circle"><i class="fa fa-home"></i></a>--><button class="btn btn-info btn-circle"><i class="fa fa-info"></i></button></h2>
<div class="container">
    <div class="row">
        <div class="col-md-4">
            <div class="information">
            <h5>Additional Information</h5>
            <p>
                Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur malesuada, magna sed sagittis posuere, nulla massa vulputate erat, sed laoreet mi nisl id quam. Nunc sodales justo quis orci sagittis tincidunt. Aliquam consectetur, metus vel commodo molestie, dui nisl vulputate nunc, sit amet varius ex nisi a ante. Donec vitae semper enim. Nullam vulputate porttitor interdum. Phasellus vel vehicula ligula, sit amet consectetur nunc. Phasellus eget facilisis arcu, sed fringilla neque. Sed urna purus, dictum eu condimentum eu, egestas vitae lacus. Nam ultricies nec ligula quis consectetur. Suspendisse posuere nulla tortor, vel pulvinar nulla fermentum non. Sed quis nulla sed mi congue sollicitudin. Morbi consectetur mi quis mauris egestas commodo. Vivamus rhoncus vestibulum orci, quis aliquam velit convallis eget.
            </p>
        </div>
        </div>
        <div class="col-md-4">
            <div class="panel panel-default">
                <div class="panel-heading">
                    <img src="../assets/logo.png">
                </div>
                <div class="panel-body">
                    <form accept-charset="UTF-8" role="form" method="post">
                        <fieldset>
                            <div class="form-group">
                                <input class="form-control" placeholder="Username" name="username" type="text">
                            </div>
                            <div class="form-group">
                                <input class="form-control" placeholder="Password" name="password" type="password">
                            </div>
                            <input class="btn btn-info btn-block" type="submit" name ="login" value="Login">
                        </fieldset>
                    </form>
                </div>
            </div>
        </div>
        <div class="col-md-4"></div>
    </div>
</div>

---

我想在用户登录时启动一个会话并存储此会话。因此，当用户重新加载登录页面时，他/她仍然登录。有人能帮我检查一下页面表单验证部分之外的会话变量吗

if(isset($_POST['login'])){
$username = $_POST['username'];
$password = $_POST['password'];
if($database->login($username, $password)){
    $loggedIn = $_SESSION['loggedIn'] = true; 
}
else{
    echo "You've failed to login";
}
}
If(isset($_SESSION['loggedIn']) &&    $_SESSION['loggedIn']==true){
header("location: ../dashboard/dashboard.php");
}

---

您意识到在实时环境中使用此代码是完全不安全的。@Fred ii-是的，我意识到这一点

if(isset($_POST['login'])){
$username = $_POST['username'];
$password = $_POST['password'];
if($database->login($username, $password)){
    $loggedIn = $_SESSION['loggedIn'] = true; 
}
else{
    echo "You've failed to login";
}
}
If(isset($_SESSION['loggedIn']) &&    $_SESSION['loggedIn']==true){
header("location: ../dashboard/dashboard.php");
}