public function findStudentLastNotValidatedCourses(Student $student, $limit = 5)
{
return $this->createQueryBuilder('c')->join('c.student', 's')->where('c.validated = false')->andWhere('s.id = :student_id')->orderBy('c.createdAt', 'DESC')->setMaxResults($limit)->setParameter(':student_id', $student->getId())->getQuery()->getResult();
}
