org.hibernate.NonUniqueResultException: query did not return a unique result: 2?

It seems like your query returns more than one result check the database. In documentation of query.uniqueResult() you can read:

Throws: org.hibernate.NonUniqueResultException – if there is more
than one matching result

If you want to avoid this error and still use unique result request, you can use this kind of workaround query.setMaxResults(1).uniqueResult();