public Course findCourseByName(String cname) {
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Course> cq = cb.createQuery(Course.class);
Root<Course> course = cq.from(Course.class);
cq.select(course).where(cb.equal(course.get("cname"), cname));
Query query = em.createQuery(cq);
Course result = (Course) query.getSingleResult();
if (result != null) {
// System.out.println("Cousre with name: " + cname + " is found");
}