JPA - Check existence of value in another table as Boolean value

Question

I have a (abbreviated) class that looks like this:

@Entity
@Table
@SecondaryTable(
        name = "SUPER_ADMIN",
        pkJoinColumns = @PrimaryKeyJoinColumn(
                name = "PERSON_ID",
                referencedColumnName = "PERSON_ID"))
public class Person {
  @Id
  @Column(name = "PERSON_ID")
  private Long personId;

  // getters/setters omitted for brevity
}

The SUPER_ADMIN table has only one column: PERSON_ID . What I would like to do is add private Boolean superAdmin to Person where it would be true if the PERSON_ID is present in that table.

Is this even possible? I am using Hibernate as my JPA provider, so I'm open to proprietary solutions as well.

UPDATE

It seems like I should have done more homework. After poking around, I see that @SecondaryTable does inner joins and not outer joins. Therefore, my idea here will not work at all. Thanks to @Elbek for the answer -- it led me to this revelation.

Answer 1

You can use JPA callback methods.

public class Person {
  @Id
  @Column(name = "PERSON_ID")
  private Long personId;

  @Transient
  private transient Boolean superAdmin = false;

  // This method will be called automatically when object is loaded
  @PostLoad
  void onPostLoad() { 
    // BTW, personId has to be present in the table since it is id column. Do you want to check if it is 1?
    superAdmin  =  personId == 1;  
  }
}

or you can create easy getter method.

public class Person {
  @Id
  @Column(name = "PERSON_ID")
  private Long personId;

  boolean isSuperAdmin() { 
      return  personId == 1;
  }
}

Answer 2

You can't have an optional relationship with a @SecondaryTable . You do not have any other choice than using a @OneToOne optional relationship in that case.