internship-playground/src-php/app/internship/model/ArticleDao.php

<?php
namespace internship\model;

use n2n\persistence\orm\EntityManager;
use internship\bo\Article;

class ArticleDao {
	private EntityManager $em;

	private function _init(EntityManager $em) {
		$this->em = $em;
	}

	function getArticles(): array {
		return $this->em->createSimpleCriteria(Article::class)->toQuery()->fetchArray();
	}

	function getArticlesByCategoryName(string $categoryName): array {
		return $this->em->createSimpleCriteria(Article::class, array('categoryName' => $categoryName))->toQuery()
				->fetchArray();
	}

	function getArticleById(int $id): ?Article {
		return $this->em->find(Article::class, $id);
	}
}