spring 开机一对一映射单向

Question

I am confused between how to setup relation between two entities. I have one entity called equipment which stored all equipment profile. This is independent of everything.

I have another entity called Analytics which should contain equipment. Note that equipment does not depend on analytics. Many analytics can contain the same equipment. That is if a user deletes analytics, nothing should happen to the actual equipment. What I am trying to do is when an analytic object is created I want to store which equipment it references.

My Equipment.java

@Entity
@Table(name = "km_equipment")
public class Equipment {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    @Column(name = "name", unique = true)
    @NotNull
    private String name;
    private String model;

My Analytics.java

@Entity
@Table(name = "km_roi")
public class ROIAnalysis {


    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private long id;
    @Column(name = "name", unique = true)
    @NotNull
    private String name;
    private String description;

    @OneToOne()
    @JoinColumn(name="id", referencedColumnName = "id", insertable = false, updatable = false)    
    Equipment equip;

I am not able to save this relationship correctly. What am I doing wrong? I believe it is still one-to-one relationship because one analytics object can only contain one equipment object.

This is the controller POST API

@RequestMapping(value = ControllerConstants.ADD_ROI, method = RequestMethod.POST)
    public ResponseEntity<?> addROI(@RequestBody ROIAnalysis roi) {
...
...
roiDao.save(roi);
...

I made a post call where my JSON payload is

{
description: "132"
equipment: {id: 5, name: "June 8 equip roi", model: "tst"}
name: "123"
}

I dont see any errors. In DB I dont see any column for equipment in analytics table. I was expecting may be the id of equipment would be stored in analytics table because when if I try to get the analytics, I want information of the equipment as well

Answer 1

You defined the relationship as @JoinColumn(name="id", referencedColumnName = "id", insertable = false, updatable = false) Why did you define that as insertable=false, updatable=false ? If you do so; any modification made to the relationship will not be reflected to the database by hibernate. Please remove insertable = false, updatable = false part in order the relationship update to be reflected to the database.

Another thing that needs to be fixed is @JoinColumn(name="id", referencedColumnName = "id") . This is weird; join column should be sth like equipment_id !

One more thing is you need to create a new ROIAnalysis entity and find and set the equipment field of that new entity to Equipment entity with id 5; which you can fetch from DB and set in regards to the example you have provided.