how to parametrize a single query

Question

i would like to have a query that contains all the category selected something like : in ProductDao

enter public List<Product> listselected(List <Product> selectedCategories) { 
     TypedQuery<Product> findQuery = em
            .createQuery(
                    "SELECT DISTINCT p FROM Product p WHERE p.idcategory='1' AND p.idcategory='2' etc ORDER BY p.idproduct",
                    Product.class);
    return findQuery.getResultList();} here

but parametrized

Answer 1

You can use this syntax:

em.createQuery("SELECT DISTINCT p FROM Product p WHERE p.idcategory IN (:categories) ORDER BY p.idproduct", Product.class)
         .setParameter("categories", selectedCategories)
         .getResultList();

Now, I don't know how you mapped a Category, but if it's an entity and Product has a field category, you can rewrite the query with:

List<Category> selectedCategories =...;
em.createQuery("SELECT DISTINCT p FROM Product p WHERE p.category IN (:categories) ORDER BY p.idproduct", Product.class)
         .setParameter("categories", selectedCategories)
         .getResultList();

I don't know if this is standard JPA, but it should work with Hibernate ORM.