具有父复合 pk 的 JPA OneToMany 是子主键派生实体问题的一部分

Question

一对多与父复合主键是子主键问题的一部分。使用以下代码 sn-ps 引发异常

示例 JSON 嵌入数据如下：

{
"pt_reg_no": "1000", //序列号生成
"game_year": "G12021",
“名字”：“我的名字”，
“事件详情”：[{ "major_event_code": "A", "sub_event_code": "A7", “category_code”：“MO” }, { "major_event_code": "B", "sub_event_code": "B7", “category_code”：“WO” } ]
}

参与者可以注册多个活动：
参与者（复合键） - pt_reg_no, game_year
EventDetails（复合键） - pt_reg_no、game_year、sub_event_code、category_code

//Parent Class IDclass
public class ParticipantKey implements Serializable {

    private Long pt_reg_no;
    private String game_year;
}

@IdClass(ParticipantKey.class)
public class ParticipantModel { 

    @Id
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "participantseq"
    )
    @SequenceGenerator(
        name = "participantseq",
        allocationSize = 1
    )
    private Long pt_reg_no;
    
    @Id
    private String game_year = 'G12021';
    
    
    @OneToMany(mappedBy = "participantModel", orphanRemoval = true, cascade = {CascadeType.ALL}, fetch = FetchType.EAGER)
    private Set<EventDetailsModel> eventDetails = new HashSet<>(); 

    public Set<EventDetailsModel> getEventDetails() {
        return eventDetails;
    }   
    public void setEventDetails(Set<EventDetailsModel> eventDetails) {
        this.eventDetails = eventDetails;

        for (EventDetailsModel b : eventDetails) {
            b.setParticipantModel(this);
        }
    }
    
}
    
//Child class IDclass    
public class ParticipantEventDetailsId implements Serializable {
        private ParticipantKey participantModel;
        private String sub_event_code;
        private String category_code;
    }
    
public class EventDetailsModel { 
      @Id    
      @Column(name = "sub_event_code")
      private String sub_event_code;
        
      @Id
      @Column(name = "category_code")
      private String category_code;
        
      @Id
      @ManyToOne(cascade = CascadeType.ALL)
      @JoinColumns({
         @JoinColumn(name = "pt_reg_no", referencedColumnName = "pt_reg_no"),
          @JoinColumn(name = "game_year", referencedColumnName = "game_year")
      })
      private ParticipantModel participantModel;


    public ParticipantModel getParticipantModel() {
        return participantModel;
    }
    public void setParticipantModel(ParticipantModel participantModel) {
        this.participantModel = participantModel;
    }
    }
    
//---------------------------------------------------
//JSON input data received into ParticipantModel from @requestBody
public class FormDataObjects {
    private ParticipantModel formData;

    @JsonCreator
    public FormDataObjects(ParticipantModel formData) {
        this.formData = formData;
    }
}

//Controller Entry point
@RequestMapping(path = "/participantData", method = RequestMethod.POST)
    @Transactional
    public ResponseEntity<?> participantRegistration(@Valid @RequestBody FormDataObjects values) {
        ParticipantModel participant = values.getFormData();
        participant.setGame_year(new SimpleDateFormat("yyyy").format(new Date()) + GenricData.game);
     
        ParticipantModel person = participantRepository.save(participant);
        
                if (person == null) {
            return ResponseEntity.ok("Participant is not inserted");
        } else {
            Set<EventDetailsModel> eventDetails = participant.getEventDetails();
            if (eventDetails.size() > 0) {
                eventDetails.forEach(event -> {
                    
                    //event.setPt_reg_no(person.getPt_reg_no());
                    //event.setGame_year(person.getGame_year());
                    //event.setParticipantModel(participant);
                    entityManager.persist(event);
                    entityManager.flush();
                    entityManager.clear();
                });

            }

        }

        return ResponseEntity.ok("inserted");
    }

Answer 1

您可以通过像这样映射您的详细信息类来尝试“派生身份”：

public class ParticipantEventDetailsId implements Serializable {
    private String sub_event_code;
    private String category_code;
    private ParticipantKey participantModel; // matches name of attribute and type of ParticipantModel PK
}
    
public class EventDetailsModel { 

    @Id
    @Column(name = "sub_event_code")
    private String sub_event_code;

    @Id
    @Column(name = "category_code")
    private String category_code;

    @Id
    @ManyToOne(cascade = CascadeType.ALL)
    @JoinColumns({
        @JoinColumn(name = "pt_reg_no", referencedColumnName = "pt_reg_no"),
        @JoinColumn(name = "game_year", referencedColumnName = "game_year")
    })
    private ParticipantModel participantModel;

}

在第 2.4.1 节的JPA 2.2 spec 中讨论了派生的身份（带有示例）。

Answer 2

OneToMany 映射的替代解决方案当父级具有复合键并且父级也需要生成序列号

在设置或列出子实体时使用 @Transient 注释
1) 使用上述注释保存父实体有助于 jpa 从保存中跳过 EventsDetailsModel 列表/集
2) 迭代 Child 并获取已保存的 Parent 复合键值，并将子数据与子键属性一起持久化。

//Parent Class IDclass
public class ParticipantKey implements Serializable {

    private Long pt_reg_no;
    private String game_year;
}

@IdClass(ParticipantKey.class)
public class ParticipantModel { 

    @Id
    @GeneratedValue(
        strategy = GenerationType.SEQUENCE,
        generator = "participantseq"
    )
    @SequenceGenerator(
        name = "participantseq",
        allocationSize = 1
    )
    private Long pt_reg_no;
    
    @Id
    private String game_year = 'G12021';
    
    @Transient  //Find exact path for Transient
    private Set<EventDetailsModel> eventDetails = new HashSet<>(); 

    public Set<EventDetailsModel> getEventDetails() {
        return eventDetails;
    }   

    
}
    
//Child class IDclass    
public class ParticipantEventDetailsId implements Serializable {
        private Long pt_reg_no;
        private String game_year;
        private String sub_event_code;
        private String category_code;
    }
    
public class EventDetailsModel { 
      @Id    
      @Column(name = "sub_event_code")
      private String sub_event_code;
        
      @Id
      @Column(name = "category_code")
      private String category_code;
        
      @Id
      private Long pt_reg_no;

      @Id
      private String game_year;
  
    }
    
//---------------------------------------------------
//JSON input data received into ParticipantModel from @requestBody
public class FormDataObjects {
    private ParticipantModel formData;

    @JsonCreator
    public FormDataObjects(ParticipantModel formData) {
        this.formData = formData;
    }
}

//Controller Entry point
@RequestMapping(path = "/participantData", method = RequestMethod.POST)
    @Transactional
    public ResponseEntity<?> participantRegistration(@Valid @RequestBody FormDataObjects values) {
        ParticipantModel participant = values.getFormData();
        participant.setGame_year(new SimpleDateFormat("yyyy").format(new Date()) + GenricData.game);
     
        ParticipantModel person = participantRepository.save(participant);
        
                if (person == null) {
            return ResponseEntity.ok("Participant is not inserted");
        } else {
            Set<EventDetailsModel> eventDetails = participant.getEventDetails();
            if (eventDetails.size() > 0) {
                eventDetails.forEach(event -> {
                    
                    event.setPt_reg_no(person.getPt_reg_no());
                    event.setGame_year(person.getGame_year());
                    entityManager.persist(event);
                    entityManager.flush();
                    entityManager.clear();
                });

            }

        }

        return ResponseEntity.ok("inserted");
    }