CODEWITHSUNDEEP
javajakarta-eejpa
user1810305
user1810305

Reputation: 23

Returnings two results sets using JPA

I am using a JPA query to get a result set, then within the same class, I would like to conditionally get more data. Here's what it looks like:

public SchoolUser getCandidatesAsJson(@PathParam("applicationId") String applicationId, @PathParam("userPassword") String userPassword ) {

    EntityManager em = createEM();

    Query query = em.createQuery("SELECT su FROM SchoolUser su WHERE su.applicationId LIKE :applicationId and su.userPassword LIKE :userPassword", SchoolUser.class);

    query.setParameter("applicationId", applicationId);
    query.setParameter("userPassword", userPassword);


    List <SchoolUser> schoolUser = query.getResultList();

    if(!schoolUser.isEmpty()) {

        SchoolUser loginRecord = schoolUser.get(0);

        int teacherId = loginRecord.getTeacherId();
        int studentId = loginRecord.getStundentId();

        if(teacherId!=0){

            TypedQuery<Classroom> query2 = em.createQuery("SELECT c FROM Classroom c where c.teacherId = :teacherId ORDER BY c.period", Classroom.class);

            query2.setParameter("teacherId", teacherId);

            List <Classroom> teacherClassList = query2.getResultList();

            if(!teacherClassList.isEmpty()){

                                    //put 2nd results set in SchoolUser object - line is commented because it causes an erro
                //loginRecord.setClassRooms(teacherClassList);

            } 

        } else if(studentId!=0){


            TypedQuery<ClassroomStudent> query3 = em.createQuery("SELECT cs FROM ClassroomStudent cs where cs.statusId = 1 AND cs.studentId = :studentId", ClassroomStudent.class);
            query3.setParameter("studentId", studentId);

                            //put results in SchoolUser object

        }



        return loginRecord;

    } else {

        SchoolUser emptyRecord = new SchoolUser();

        return emptyRecord;
    }



}

The error comes from putting the Classroom JPA object into the SchoolUser object - since these two objects don't have a direct relationship.

Any way that I can accomplish this with JPA?

Upvotes: 1

Views: 92

Answers (1)

0x6C38
0x6C38

Reputation: 7076

If you do not want to persist the classroom (or any other attribute for that matter) then the @Transient annotation allows you to ignore a particular field so that JPA won't try to map it.

This annotation specifies that the property or field is not persistent. It is used to annotate a property or field of an entity class, mapped superclass, or embeddable class.

Example:
@Entity
public class Employee {
    @Id int id;
    @Transient User currentUser;
    ...
}

Upvotes: 1

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