public Collection getProducts(String catID) {
   return em.createQuery("SELECT p FROM Product p WHERE p.categoryID LIKE :categoryID")
       .setParameter("categoryID", catID)
       .getResultList();
 }
 public Collection getItems(String prodID) {
   return em.createQuery("SELECT i FROM Item i WHERE i.productID LIKE :productID")
       .setParameter("productID", prodID)
       .getResultList();
 }
 public Collection getCategories() {
   return em.createQuery("SELECT OBJECT(c) FROM Category_1 c").getResultList();
 }