我想獲得Deelnemers下的用戶列表:誰註冊了該課程。我不知道如何做到這一點現在已經嘗試了一段時間。數據庫看起來像下面的圖片。 從登錄課程的用戶獲取信息
<?php
session_start();
require_once('includes/mysql_config.php');
$id = isset($_SESSION['id']) ? $_SESSION['id'] : header('location: login.php');
$Cursist = mysqli_query($con, "SELECT id FROM users WHERE id =".$_SESSION['id']);
require_once('header.php');
$cursus = mysqli_fetch_array(mysqli_query($con, "SELECT id FROM cursus WHERE id =".$_GET['id']));
?>
<div class="container">
<div class="row">
<div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
<div class="post-preview">
<h2 class="post-title">
<?php echo $cursus['title'] . "<br />";?>
<?php echo $cursus['beginDatum'] . "<br />";?>
Deelnemers:
<?php
$sql = mysqli_fetch_array(mysqli_query($con, "SELECT * FROM users t WHERE EXISTS(SELECT * FROM aanmeldingen B WHERE t.id = b.user_id)"));
$amount = mysqli_affected_rows($con);
for ($i = 0; $i < $amount; $i++) {
$user = mysqli_fetch_array($sql);
echo $user['email']. "<br />";
}?>
</h2>
</div>
</div>
</div>
</div>
我怎樣才能得到這個工作,因爲我不知道如何做到這一點了
那麼,什麼是錯誤,你期望從代碼中得到什麼?在查詢'SELECT * FROM users t WHERE EXISTS(SELECT * FROM aanmeldingen B WHERE t.id = b.user_id)'查詢,看起來像你試圖檢索用戶和它的相關cursus? –
你是什麼意思與「Deelnemers」,我沒有看到它在你的代碼/數據庫中的那個詞。 – Grey
@Luuk,它的代碼,使用Ctrl + F,起初我沒有找到它。 反正marjin,你可能需要參考[多對多關係](http://lornajane.net/posts/2011/inner-vs-outer-joins-on-a-many-to-many-關係) –