How to write query in JPQL?

Question

I have a three classes: Doctor, Patient and Consultation. Both Doctor and Patient classes have a list of consultations as field.

@Entity
public class Consultation {
    @Id
    @GeneratedValue
    private int id;
    private Calendar scheduleDate;
    private String information;
    private String symptoms;
    @ManyToOne
    private Doctor doctor;
    @ManyToOne
    private Patient patient;
//...
}

@Entity
public class Patient {
    @Id
    @GeneratedValue
    private int id;
    private String name;
    private String ssn;
    private String address;
    @OneToMany(mappedBy = "patient")
    private List<Consultation> consultations;
//...
}

@Entity
public class Doctor  {
    @Id
    @GeneratedValue
    private int id;
    private String name;
    private String specialization;
    @OneToMany(mappedBy = "doctor")
    private List<Consultation> consultations;
//...
}

I want to obtain the patients of a doctor from a single query; that is all the patients that have the same consultation as a doctor. Note that there is no connection between Doctor and Patient. Is this posible?

select p from Patient p where p.consultations **someKeyword** (select d.consultations from Doctor d where d.id = :doctorId)

If I'm not mistaken someKeyword would be contains if there would be

where list<entity> contains entity

and in if

where entity in list<entity>

but in this case there would be

list someKeyword list

A combination would be:

select p from Patient p where p.consultations contains (select c from Consultation c where c in (select d.consultations from Doctor d where d.id = :doctorId))

but does this make sens?

I am a beginner in JPA and JPQL.

Answer 1

Something like:

select p from Patient p
where exists (
    select c from Consultation c
    where c.patient = p
    and c.doctor.id = :doctorId
)

?