$db_host = 'localhost';
$db_user = 'db user';
$db_pass = 'db password';
$db_name = 'db name';

// создаем объект подключения к базе данных
$dbh = new PDO("mysql:host={$db_host};dbname={$db_name}", $db_user, $db_pass);

// функция получает каталог. При необходимости ведет поиск. Работает с пагинацией.
function get_catalog($search = null, $page = 0, $all = false) {
    global $dbh;
    $return = [];
    $wh = '';
    $limit = 0;
    $offset = 9;

    if(isset($search['page'])) {
        $limit = ($search['page']-1) * 9;
        $offset = 9;

        unset($search['page']);
    }



    if($search != null) {
        $wh = ' where ';
        $and = [];


        foreach($search as $key=>$param) {
            if(is_array($param)) {
                foreach($param as $v) {
                    $and[] = "`{$key}` LIKE '%{$v}%'";
                }
            } else {
                $and[] = "`{$key}` LIKE '%{$param}%'";
            }
        }

        $and_str = implode(" AND ", $and);

        $wh .= $and_str;
    }


    $all_str = $all === false ? '' : "limit {$limit}, {$offset}";

    $sql = "SELECT * FROM goods {$wh} {$all_str}";
    $query = $dbh->query($sql);

    $rows = $query->fetchAll(PDO::FETCH_ASSOC);

    foreach($rows as $row){
        $row['composition'] = get_composition($row['id']);

        if($row['images'] != null) {
            $image_ids = explode(",", $row['images']);

            foreach($image_ids as $img_id) {
                $row['image'][] = get_image_by_id($img_id)['rows'][0]??[];
            }
        }

        $return['rows'][] = $row;
    }


    return $return;
}