java - 如何用JPQL编写查询？

Question

我有三个类(class):医生、病人和咨询。医生和病人类(class)都有一个咨询列表作为字段。

@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;
//...
}

我想通过一次查询获取某个医生的病人；那就是所有与医生进行相同咨询的患者。请注意，医生和患者之间没有任何联系。这可能吗？

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

如果我没记错的话someKeyword将是包含如果有

where list<entity> contains entity

和中如果

where entity in list<entity>

但是在这种情况下会有

list someKeyword list

组合如下:

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))

但这有意义吗？

我是 JPA 和 JPQL 的初学者。

Answer 1

类似于:

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

？