class DbtngExampleController

class DbtngExampleController extends ControllerBase {
    
    /**
     * The repository for our specialized queries.
     *
     * @var \Drupal\dbtng_example\DbtngExampleRepository
     */
    protected $repository;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        $controller = new static($container->get('dbtng_example.repository'));
        $controller->setStringTranslation($container->get('string_translation'));
        return $controller;
    }
    
    /**
     * Construct a new controller.
     *
     * @param \Drupal\dbtng_example\DbtngExampleRepository $repository
     *   The repository service.
     */
    public function __construct(DbtngExampleRepository $repository) {
        $this->repository = $repository;
    }
    
    /**
     * Render a list of entries in the database.
     */
    public function entryList() {
        $content = [];
        $content['message'] = [
            '#markup' => $this->t('Generate a list of all entries in the database. There is no filter in the query.'),
        ];
        $rows = [];
        $headers = [
            $this->t('Id'),
            $this->t('uid'),
            $this->t('Name'),
            $this->t('Surname'),
            $this->t('Age'),
        ];
        $entries = $this->repository
            ->load();
        foreach ($entries as $entry) {
            // Sanitize each entry.
            $rows[] = array_map('Drupal\\Component\\Utility\\Html::escape', (array) $entry);
        }
        $content['table'] = [
            '#type' => 'table',
            '#header' => $headers,
            '#rows' => $rows,
            '#empty' => $this->t('No entries available.'),
        ];
        // Don't cache this page.
        $content['#cache']['max-age'] = 0;
        return $content;
    }
    
    /**
     * Render a filtered list of entries in the database.
     */
    public function entryAdvancedList() {
        $content = [];
        $content['message'] = [
            '#markup' => $this->t('A more complex list of entries in the database. Only the entries with name = "John" and age older than 18 years are shown, the username of the person who created the entry is also shown.'),
        ];
        $headers = [
            $this->t('Id'),
            $this->t('Created by'),
            $this->t('Name'),
            $this->t('Surname'),
            $this->t('Age'),
        ];
        $rows = [];
        $entries = $this->repository
            ->advancedLoad();
        foreach ($entries as $entry) {
            // Sanitize each entry.
            $rows[] = array_map('Drupal\\Component\\Utility\\Html::escape', $entry);
        }
        $content['table'] = [
            '#type' => 'table',
            '#header' => $headers,
            '#rows' => $rows,
            '#attributes' => [
                'id' => 'dbtng-example-advanced-list',
            ],
            '#empty' => $this->t('No entries available.'),
        ];
        // Don't cache this page.
        $content['#cache']['max-age'] = 0;
        return $content;
    }

}