update @OneToMany relationship (Spring Boot, Spring Data)-CodePudding

I have a OneToMany relationship (two tables bi-directional). When I save the doctor's specialties, it does work, but when I remove any specialty and update the doctor, it doesn't.

Doctor

@Entity
@Table(name = "doctors")
public class Doctor implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer doctorId;

    @Column(length = 20)
    private String doctorName;

    @Column(length = 9)
    private String doctorPhoneNo;

    @Column(length = 30)
    private String doctorEmailAddress;

    private String doctorProfileImage;

    @Enumerated(EnumType.STRING)
    private Status status;

    @Column(length = 6)
    private String doctorCmp;

    @OneToMany(mappedBy = "doctor", cascade = CascadeType.ALL)
//  @JsonIgnore
    private Set<DoctorSpecialties> doctorSpecialties;

    public Doctor() {
        this.doctorSpecialties = new HashSet<>();
    }

    public Doctor(Integer id){
        this();
        this.doctorId = id;
    }

    // getters y setters
}

Specialty

@Entity
@Table(name = "specialties")
public class Specialty implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer specialtyId;

    private String specialtyName;

    @OneToMany(mappedBy = "specialty")
    @JsonIgnore
    private Set<DoctorSpecialties> doctorSpecialties;

    public Specialty() {
    }

    public Specialty(Integer id) {
        this.specialtyId = id;
    }

    // getters and setters
  }

DoctorSpecialties

@Entity
@Table(name = "doctor_specialties")
public class DoctorSpecialties implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "doctor_id")
    private Doctor doctor;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "specialty_id")
    private Specialty specialty;

    @OneToMany
    @JoinColumn(name = "doctor_specialties_id")
    private Set<Appointment> appointments;

    @OneToMany
    @JoinColumn(name = "doctor_specialties_id")
    private Set<DoctorSchedule> schedules;

    public DoctorSpecialties(){

    }

    public DoctorSpecialties(Specialty specialty, Doctor doctor){
        this.specialty = specialty;
        this.doctor = doctor;
    }
      getters / setters
 }

Controller

@PostMapping(value = "/saveSpecialties/{id}")
public String saveDoctorSpecialties(@RequestParam(required = false) String[] specialtiesId,
                                    @PathVariable Integer id, RedirectAttributes message) {

    if (id != null && id > 0) {
        Doctor doctor = doctorService.findOne(id);

        if (doctor != null) {

            // It does not work
            doctor.getDoctorSpecialties().forEach(ds -> doctorSpecialtiesService.delete(ds.getId()));

            doctor.getDoctorSpecialties().clear();

            if (specialtiesId != null) {
                for (String specialtyId : specialtiesId) {
                    DoctorSpecialties ds = new DoctorSpecialties();
                    ds.setSpecialty(new Specialty(Integer.parseInt(specialtyId)));
                       
                    ds.setDoctor(doctor);

                    doctor.getDoctorSpecialties()
                            .add(ds);
                }
                
            }
            doctorService.update(doctor);
            message.addFlashAttribute("success", "Specialties successfully saved.");
            return "redirect:/doctors/profile/{id}/specialties";
        }
    }
    // specialtiesId = new String[]{};
    message.addFlashAttribute("error", "Doctor doesn't exists");
    return "redirect:/doctors/list";
}

console:

2021-10-30 21:19:13.330 DEBUG 44504 --- [nio-8080-exec-7] org.hibernate.SQL : select doctor0_.doctor_id as doctor_i1_3_0_, doctor0_.doctor_cmp as doctor_c2_3_0_, doctor0_.doctor_email_address as doctor_e3_3_0_, doctor0_.doctor_name as doctor_n4_3_0_, doctor0_.doctor_phone_no as doctor_p5_3_0_, doctor0_.doctor_profile_image as doctor_p6_3_0_, doctor0_.status as status7_3_0_ from doctors doctor0_ where doctor0_.doctor_id=? 2021-10-30 21:19:13.339 DEBUG 44504 --- [nio-8080-exec-7] org.hibernate.SQL : select doctorspec0_.doctor_id as doctor_i2_2_0_, doctorspec0_.id as id1_2_0_, doctorspec0_.id as id1_2_1_, doctorspec0_.doctor_id as doctor_i2_2_1_, doctorspec0_.specialty_id as specialt3_2_1_ from doctor_specialties doctorspec0_ where doctorspec0_.doctor_id=? 2021-10-30 21:19:13.401 DEBUG 44504 --- [nio-8080-exec-8] org.hibernate.SQL : select doctor0_.doctor_id as doctor_i1_3_0_, doctor0_.doctor_cmp as doctor_c2_3_0_, doctor0_.doctor_email_address as doctor_e3_3_0_, doctor0_.doctor_name as doctor_n4_3_0_, doctor0_.doctor_phone_no as doctor_p5_3_0_, doctor0_.doctor_profile_image as doctor_p6_3_0_, doctor0_.status as status7_3_0_ from doctors doctor0_ where doctor0_.doctor_id=? 2021-10-30 21:19:13.404 DEBUG 44504 --- [nio-8080-exec-8] org.hibernate.SQL : select specialty0_.specialty_id as specialt1_7_0_, doctorspec1_.id as id1_2_1_, doctor2_.doctor_id as doctor_i1_3_2_, specialty0_.specialty_name as specialt2_7_0_, doctorspec1_.doctor_id as doctor_i2_2_1_, doctorspec1_.specialty_id as specialt3_2_1_, doctorspec1_.specialty_id as specialt3_2_0__, doctorspec1_.id as id1_2_0__, doctor2_.doctor_cmp as doctor_c2_3_2_, doctor2_.doctor_email_address as doctor_e3_3_2_, doctor2_.doctor_name as doctor_n4_3_2_, doctor2_.doctor_phone_no as doctor_p5_3_2_, doctor2_.doctor_profile_image as doctor_p6_3_2_, doctor2_.status as status7_3_2_ from specialties specialty0_ inner join doctor_specialties doctorspec1_ on specialty0_.specialty_id=doctorspec1_.specialty_id inner join doctors doctor2_ on doctorspec1_.doctor_id=doctor2_.doctor_id where doctor2_.doctor_id=? 2021-10-30 21:19:13.565 DEBUG 44504 --- [nio-8080-exec-4] org.hibernate.SQL : select specialty0_.specialty_id as specialt1_7_0_, doctorspec1_.id as id1_2_1_, doctor2_.doctor_id as doctor_i1_3_2_, specialty0_.specialty_name as specialt2_7_0_, doctorspec1_.doctor_id as doctor_i2_2_1_, doctorspec1_.specialty_id as specialt3_2_1_, doctorspec1_.specialty_id as specialt3_2_0__, doctorspec1_.id as id1_2_0__, doctor2_.doctor_cmp as doctor_c2_3_2_, doctor2_.doctor_email_address as doctor_e3_3_2_, doctor2_.doctor_name as doctor_n4_3_2_, doctor2_.doctor_phone_no as doctor_p5_3_2_, doctor2_.doctor_profile_image as doctor_p6_3_2_, doctor2_.status as status7_3_2_ from specialties specialty0_ inner join doctor_specialties doctorspec1_ on specialty0_.specialty_id=doctorspec1_.specialty_id inner join doctors doctor2_ on doctorspec1_.doctor_id=doctor2_.doctor_id where doctor2_.doctor_id=?

There is no delete statement...

------------------------ EDIT ------------------------

Doctor find = doctorRepository.findById(1).get();
    
DoctorSpecialties ds1 = new DoctorSpecialties();
ds1.setSpecialty(specialtyRepository.findById(1).get());
ds1.setDoctor(find);
    
DoctorSpecialties ds2 = new DoctorSpecialties();
ds2.setSpecialty(specialtyRepository.findById(2).get());
ds2.setDoctor(find);
    
find.getDoctorSpecialties().add(ds1);
find.getDoctorSpecialties().add(ds2);

doctorRepository.save(find);

I have done some tests and I can not understand completely. I did and it only saves once when actually I am adding two objects.

insert into doctor_specialties (id, doctor_id, specialty_id) values (null, ?, ?)

CodePudding user response：

Whichever side has mappedBy is owning side.

This means something like: "modifications on this side of the relation are already Mapped By the other side of the relation , so no need to track it here separately in an extra table."

Check this url for more information What is the "owning side" in an ORM mapping?

CodePudding user response：

For the one-many relationship in a transaction, once you get the parent (Doctor) and loop over its children (DoctorSpecialties) [In other words, once you load entire the parent and its children into Persistent state], you won't be able to delete your DoctorSpecialties directly by its repository.

You could try something like the below example to see it:

@Transactional
public void removeLine(Long doctorId, Long specId) {
    Doctor doctor = this.doctorRepository  // (1)
        .findById(doctorId)
        .orElseThrow(IllegalArgumentException::new);
    this.doctorSpecialtiesRepository.deleteById(specId); // (2)
}

At (1), we load doctor into the persistent state. So here, if fetch = FetchType.EAGER, this means that it will load doctor and its all doctorSpecialties into the persistent state and this cause (2) won't give you any effect.

Otherwise, if fetch = FetchType.LAZY, it only load doctor into the persistent state, and at (2) it will be deleted successfully.

Your case was similar, although fetch = FetchType.LAZY, but you looped over the children by using forEach and that loads doctorSpecialties into the persistent state. That's why you cannot delete them.

Suggestion: Using orphanRemoval = true in your parent entity

@OneToMany(mappedBy = "doctor", cascade = CascadeType.ALL, orphanRemoval = true)
    private Set<DoctorSpecialties> dss;

and just simply clear its children in your method (In @Transactional method)

doctor.getDoctorSpecialties().clear();