Mysqli查询与窗体不起作用 - 一切看起来都正确，没有语法

Question

我已经检查过，但没有任何东西适合我的问题，实际上看起来没什么问题。也许我只是累了，也许我只是坏，这里是代码：

<?php
if(isset($_POST['add_room'])){
    include('php/connect.php');
    $desc = $_POST['room_description'];
    $cleaned = 1;
    $cleaner = "admin";
    $date = gmdate("Y-m-d H:i:s");

    $sql = "INSERT INTO rooms (Desc, Cleaned, Cleaner, Time) VALUES ('$desc', '$cleaned', '$cleaner', '$date')";

    mysqli_query($conn, $sql);

};
?>

<div id="slide-admin" style="display: none;" class="col-xs-offset-1 col-xs-10 col-xs-offset-1 col-md-offset-2 col-md-8 col-md-offset-2 sd-adm">
<div class="btn btn-default add_room-btn">Nytt rum?</div>    
<div class="add_room" style="display:none;">
    <form class="add_room-form" method="post">
        <input name="room_description" class="room_description" placeholder="Rumsinfo"></input>
        <input name="add_room" value="Lägg till rum" type="submit" class="btn btn-success add_room-btn-send"></input>
    </form>
</div>

*硬编码的值仅用于测试目的，connect.php已经过测试并正常工作，是的，我有sql注入漏洞，只是测试。