Hibernate Join two unrelated table when both has Composite Primary Key

Finally I found out that

Criteria API does not support joining unrelated entities. JPQL does not support that either. However, Hibernate supports it in HQL since 5.1. https://discourse.hibernate.org/t/join-two-table-when-both-has-composite-primary-key/1966

Maybe there is some workarounds, but in this case, I think the better way is to use HQL instead of Criteria API.

Here is HQL implementation code snippet (nothing was changed in entity classes)

String hql = "FROM Transaction t \r\n" + 
             " LEFT OUTER JOIN FETCH t.rc r \r\n" +
             " WHERE (t.merchantID IN (:merchant_id))\r\n" +
             " AND (t.authRequestDate BETWEEN :from AND :to)\r\n" +
             " AND (r.rcLang = :rcLang or r.rcLang is null)\r\n";

Query query =  session.createQuery(hql,Transaction.class);
query.setParameter("merchant_id", tRequest.getMerchantList());
query.setParameter("rcLang", tRequest.getLang());
query.setParameter("from", dateFrom);
query.setParameter("to", dateTo);

List<Transaction> dbTransaction = query.getResultList();

Change the relation from @OneToOne to @OneToMany and use fetch instead of join , it will execute only one query and hopefully it works.

 Join<Transaction, ResponseCode> join =
        (Join<Transaction,ResponseCode>)transaction.fetch("rc",JoinType.LEFT);

and you can try it with @OneToOne too.