JPA 2.0 Native Query Result Mapping to a Bean or an Array

Removed

Working with JPA 2.0, I wanted to Construct a Bean (Array of Beans) by executing a Native Query.
Using the NamedQuery, we can declare the wanted new Bean, not necessarily an entity. This is done through this Declaration :

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@NamedQuery(name="findPerson", query = "SELECT new org.nd.enterprise.bean.PersonDetail(e.personId, e.birthDate)" + " FROM Person p WHERE p.personId = :person")

We need to provide a constructor Containing exactly these parameters.

So Now coming back to the Native query. Sometime, the Query is quite complex so that we need to have it as Native Query. But in that case, it is not possible to declare the Bean inside the Query. And by using the below line we will get an error: org.hibernate.MappingException: Unknown entity: org.nd.enterprise.bean.PersonDetail

1	// Here we declare just a String query = "select ...." List<PersonDetail> rec2 = entityManager.createNativeQuery(query,PersonDetail.class).getResultList();

This problem is resolved in JPA 2.1, see this post.
But in JPA 2.0, we may use this code :

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public List<PersonDetail> getPersonByEnterprise(String enterpriseId, List<String> personIds){ @SuppressWarnings("unchecked") List<PersonDetail> records = entityManager.createNamedQuery("personDetailsByEnterprise").setParameter("enterpriseId", enterpriseId).setParameter("personIds", personIds).getResultList(); List<PersonDetail> personRecords = new ArrayList<PersonDetail>(); @SuppressWarnings("rawtypes") Iterator it = records.iterator( ); while (it.hasNext( )) { Object[] result = (Object[])it.next(); // Iterating through array object personRecords.add(new PersonDetail(result[0], result[1], result[2], result[3], result[4], result[5], result[6], result[7])); } return personRecords; }

So now, don't forget to create the appropriate constructor for PersonDetail.

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public PersonDetail(Object enterprise_id, Object person_id, Object name, Object surname, Object profession, Object status, Object age, Object lunch_time) { this.enterpriseId = (String) enterprise_id; this.personId = (String) person_id; this.name = (String) name; this.surname =(String) surname; this.profession = (String) profession; if(status != null ){ this.status = StatusEnum.valueOf((String) status); } this.age = (Integer) age; this.lunchTime= (Date) lunch_time; }

That's it, hope it helps you :).