问PHP和Bootstrap中的多项轮播

EN

.carousel-item{
    width:300px;
    height:400px;
    border:1px solid var(--grey3);
}

$related .= '<div id="carouselExampleControls" class="carousel slide" data-ride="carousel">';
$related .= '<div class="carousel-inner">';

$i = 0;
$params = [$product_name,$product_name,$_SESSION['locale']['product_set']];
$sql = "SELECT * FROM products WHERE MATCH(product_name) AGAINST(?) AND product_name!=? AND product_set=? LIMIT 15";
$stmt = DB::run($sql,$params);
while ($row = $stmt->fetch(PDO::FETCH_ASSOC)){
    $related_product_id = $row["id"];
    $related_product_name = $row["product_name"];

    $related .= '<div class="carousel-item';
    if($i==0){$related .= ' active';}
    $related .= '">';
    $related .= '//product_info';
    $related .= '</div>';

    $i++;
}

$related .= '</div>';
$related .= '<a class="carousel-control-prev" href="#carouselExampleControls" role="button" data-slide="prev">';
$related .= '&lsaquo;';
$related .= '</a>';
$related .= '<a class="carousel-control-next" href="#carouselExampleControls" role="button" data-slide="next">';
$related .= '&rsaquo;';
$related .= '</a>';
$related .= '</div>';