private static function insert(Article $model)
 {
     $db = Database::getInstance('app');
     $query = "INSERT INTO articles (title,content,post_date,articleImage,titleBG,contentBG) VALUES (:title, :content, :post_date, :articleImage, :titleBG, :contentBG);";
     $result = $db->prepare($query);
     $result->execute([':title' => $model->getTitle(), ':content' => $model->getContent(), ':post_date' => $model->getPost_date(), ':articleImage' => $model->getArticleImage(), ':titleBG' => $model->getTitleBG(), ':contentBG' => $model->getContentBG()]);
     $model->setId($db->lastId());
 }