JPA EclipseLink getCount of child entity - jpa

Question

I am using EL and i keep getting 0 when i run the query below. I want to get the count of applicants (AP) that are currently active. The child entity Applicant is of Person and i want to avoid querying all elements of Person?
#RooJavaBean
#RooToString
#RooEntity(identifierColumn = "personID", inheritanceType = "SINGLE_TABLE")
#DiscriminatorColumn(name = "TYPE", discriminatorType = DiscriminatorType.STRING, length = 20)
#DiscriminatorValue("P")
public class Person {
#NotNull
#Size(min = 1, max = 50)
private String FirstName;
#NotNull
#Size(min = 1, max = 50)
private String LastName;
}
The child entity 'Applicant'
#RooJavaBean
#RooToString
#RooEntity
#DiscriminatorValue("AP")
public class Applicant extends Person{
private String major;
private String nativeLanguage;
private String ethnicity;
private String hispanic;
}
My query attempt:
/**
*
* #return
*/
public int getCountActiveApplicants(){
EntityManager entityManager = factory.createEntityManager();
int value = entityManager.createQuery("select count(distinct o) from Person o where o.TYPE = \"AP\" AND o.active = \"Yes\" ").getFirstResult();
System.out.println("wowzer " + value + "\n");
return value;
}

Answer 1

Why don't you simply count the applicants?
select count(distinct a) from Applicant a where a.active = true
EclipseLink will transform this in SQL and add the where clause on the discriminator for you.
Remember that JPQL works with your entities and their persistent fields/properties. It knows about their association and their inheritance hierarchy. JPQL never uses table and column names.
(Side note: why use "Yes" for a boolean field?)