How do I return the size of the largest collection in JPA?

Here's my code:

@Entity
@Table("Books")
public class BookImp implements Book {

@Id
@GeneratedValue
@Column(name = "id")
private Long id;

@ElementCollection
private Set<String> authors = new HashSet<String>();

// getters + constructors

}

      

        
        
        
      

    

I want to create a SQL query that will return the size of the largest collection of authors. How can i do this?

EDIT: For anyone suggesting using a for loop, this is how I want the answer to look like this:

@Override
public int getLargestAuthors() {
return entityManager.createQuery("select b.authors from BookImpl b where b.authors.size ...").getSingleResult().size();
}