如何使用 HQL 将 hibernate 中的所有行 select 与额外表一起使用

Question

Update 2

Query:

select distinct p.name, u.cookie_id
    from product p
    left join user_product up on p.id = up.product_id
    left join user u on up.user_id = u.id
    where p.active = true
    and
    (
       u.cookie_id = '4c2fe5b2-73fe-4b28-baa6-23db0512114c'
           or
       not (exists (
         select p1.id
         from user_product up1, product p1
         where p1.id = up1.product_id
       ))
    )

Output:

how should be:

Update 1

I wrote the code with the use of stream() for the better understanding of the problem:

        List<Product> productList = productRepository.findAllByActiveTrue();
        productList = productList.stream().map(item -> {
            if(item.getUserProducts() == null) return item;

            List<UserProduct> userProductList = new ArrayList<>();
            for (UserProduct userProduct : item.getUserProducts()) {
                if(userProduct.getUser().getCookieId().equals(cookieId)){
                    userProductList.add(userProduct);
                }
            }
            item.setUserProducts(userProductList);
            return item;
        }).collect(Collectors.toList());

I would like to know how correctly select data from the tables. I want to get all products.

But to get all products is easy. I also need to include in the output data (UserProducts and User) if there's a connection between Product and User by CookieId. In other words, I want to show all products with User and UserProducts (if possible) and exclude the relation Product-UserProduct-User if User's cookieId doesn't match the cookieId from the query.

I am trying the following query, but it returns me only products that has the connection between User and the product, not all products.

@Query("from Product pr join fetch pr.userProducts up left join fetch up.user u where pr.active = true and u.cookieId = :cookieId")
    List<Product> getAllProductsByCookieId(UUID cookieId);

My database looks like this:

Visualisation of the idea:

SQL-queries to generate tables:

product-table

create table if not exists product
(
    id bigint auto_increment
        primary key,
    active bit not null,
    image_path varchar(255) null,
    name varchar(255) null,
    price double not null,
    unit_number double null,
    unit_type varchar(255) null
);

userProduct-table

create table if not exists user_product
(
    quantity int null,
    product_id bigint not null,
    user_id bigint not null,
    primary key (product_id, user_id),
    constraint FKnw43wab2rt35jmofmpbhkibco
        foreign key (product_id) references product (id),
    constraint FKq5o2e33vlwpfc2k1mredtia6p
        foreign key (user_id) references user (id)
);

user-table

create table if not exists user
(
    id bigint auto_increment
        primary key,
    cookie_id varchar(255) null
);

Answer 1

1. Your requirement is not possible without scaler objects in JPA. ie JPA cannot give you a Product object where p.getUserProducts() contains only some UserProducts .

   • See my answer here. Why left join on CriteriaQuery doesn't filter results?
   • or here problems with OneToMany including a filter clause in spring jpa

2. You have to use the native query option or any other option where you retrieve the columns and provide a mapper as to how to create the object. You can use the following sql query.

    select p.product, u.cookie_id 
    from product p 
    left join user_product up on p.id = up.product_id 
    left join user u on up.user_id = u.id and u.cookie_id = '?1'
    where p.active = true
    group by p.product, u.cookie_id