Wut?

Functions

/* * * * * * * * * * * * * * * *
* Returns all posts under a category
* * * * * * * * * * * * * * * * */
function getPublishedPostsByCategory($category_id) {
    global $conn;
    $sql = "SELECT * FROM posts ps
            WHERE ps.id IN
            (SELECT pt.post_id FROM post_category pt
                WHERE pt.category_id=$category_id GROUP BY pt.post_id
                HAVING COUNT(1) = 1)";
    $result = mysqli_query($conn, $sql);
    // fetch all posts as an associative array called $posts
    $posts = mysqli_fetch_all($result, MYSQLI_ASSOC);

    $final_posts = array();
    foreach ($posts as $post) {
        $post['category'] = getPostCategory($post['id']);
        array_push($final_posts, $post);
    }
    return $final_posts;
}
/* * * * * * * * * * * * * * * *
* Returns category name by category id
* * * * * * * * * * * * * * * * */
function getCategoryNameById($id)
{
    global $conn;
    $sql = "SELECT name FROM categories WHERE id=$id";
    $result = mysqli_query($conn, $sql);
    $category = mysqli_fetch_assoc($result);
    return $category['name'];
}
?>

Page markup

<?php include('config.php'); ?>
<?php include('includes/public_functions.php'); ?>
<?php include('includes/head.php'); ?>
<?php
    // Get posts under a particular topic
    if (isset($_GET['category'])) {
        $category_id = $_GET['category'];
        $posts = getPublishedPostsByCategory($category_id);
    }
?>
    <title>LifeBlog | Home </title>
</head>
<body>
<div class="container">
<!-- Navbar -->
    <?php include( ROOT_PATH . '/includes/nav.php'); ?>
<!-- // Navbar -->
<!-- content -->
<div class="content">
    <h2 class="content-title">
        Articles on <u><?php echo getCategoryNameById($category_id); ?></u>
    </h2>
    <hr>

     <!-- gets posts from db -->
     <?php foreach ($posts as $post): ?>
        <div class="card md-8">
       <div class="card-body">

  <!-- image from db -->

   <img src="<?php echo BASE_URL . '/img/' . $post['image']; ?>" class="post_image" alt="post image" style="width:100%;margin-bottom:0">
                    </div>
                </div>
            </a>
        </div>
    <?php endforeach ?>
</div>
<!-- // content -->
</div>
<!-- // container -->

<!-- Footer -->
    <?php include( ROOT_PATH . '/includes/footer.php'); ?>
<!-- // Footer -->