/**
 * The repository for Trainings
 */
class TrainingRepository extends \TYPO3\CMS\Extbase\Persistence\Repository
{
public function findDemanded($demand) {
        $query = $this -> createQuery();
        $query -> getQuerySettings() -> setRespectStoragePage(FALSE);
        $constraints = $this -> createConstraintsFromDemand($query, $demand);
        if (!empty($constraints)) {
            $query -> matching(
            $query -> logicalAnd($constraints)
        );
        }
        return $query -> execute();
    }


    protected function createConstraintsFromDemand(\TYPO3\CMS\Extbase\Persistence\QueryInterface $query, $demand) {
        $constraints = array();

        $categories = $demand -> getCategories();
        if ((!empty($categories))) {
            $categoryConstraints = array();
            $categories = \TYPO3\CMS\Core\Utility\GeneralUtility::intExplode(',', $categories, TRUE);
            foreach ($categories as $category) {
                $categoryConstraints[] = $query -> contains('categories', $category);
            }
            $constraints = $query -> logicalOr($categoryConstraints);
        }
        return $constraints;
    }
    }