create table ORMREL_PERSON (
        PERSON_ID bigint generated by default as identity,
        firstName varchar(255),
        lastName varchar(255),
        phone varchar(255),
+-----  PERSON_PHOTO bigint,
|       primary key (PERSON_ID)
|   )
|   create table ORMREL_PHOTO (
+-----> PHOTO_ID bigint generated by default as identity,
        image blob,
        primary key (PHOTO_ID)
    )
    alter table ORMREL_PERSON 
        add constraint FK14D7C425DCCB1C0D 
        foreign key (PERSON_PHOTO) 
        references ORMREL_PHOTO

    @Entity

    @Table(name="ORMREL_PERSON")

    public class Person  {

        @Id @GeneratedValue @Column(name="PERSON_ID")

        private long id;

    

        @OneToOne(cascade={ 

                CascadeType.ALL},  //have creates, deletes, etc. cascade to photo

                fetch=FetchType.LAZY)       //a hint that we don't need this

        @JoinColumn(name="PERSON_PHOTO")    //define local foreign key column

+-----  private Photo photo;

|   

|   @Entity

|   @Table(name="ORMREL_PHOTO")

|   public class Photo {

|       @Id @GeneratedValue @Column(name="PHOTO_ID")

+---->  private long id;

    create table ORMREL_APPLICANT (
        id bigint generated by default as identity,
+-----  APP_BORROWER bigint,
|       APP_PERSON bigint not null,
|       primary key (id)
|   )
|   create table ORMREL_BORROWER (
+---->  BORROWER_ID bigint not null,
        endDate date,
        startDate date,
        primary key (BORROWER_ID)
    )
    alter table ORMREL_APPLICANT 
        add constraint FKD1860812DA35F52F 
        foreign key (APP_BORROWER) 
        references ORMREL_BORROWER

    @Entity @Table(name="ORMREL_APPLICANT")

    public class Applicant  {

        @Id @GeneratedValue

        private long id;

        

  +-->  @OneToOne(optional=true)        //we may exist without Borrower 

  |     @JoinColumn(name="APP_BORROWER")//we own relationship to Borrower

+-----  private Borrower borrower;

| |

| | @Entity @Table(name="ORMREL_BORROWER")

| | public class Borrower  {

| |     @Id @Column(name="BORROWER_ID")

`---->  private long id;

  |    

  |     @OneToOne(fetch=FetchType.LAZY, 

  |             optional=true,       //lets make this optional for demo 

  |             mappedBy="borrower") //the other side owns foreign key column

  +--   private Applicant application;

        //locate them from DB

        Applicant applicant2 = em.find(Applicant.class, applicant.getId());

        Borrower borrower2 = em.find(Borrower.class, borrower.getId());

        

        //form relationship

        borrower2.setApplication(applicant2); //set inverse side

        applicant2.setBorrower(borrower2);    //set owning side

    update
        ORMREL_APPLICANT 
    set
        APP_BORROWER=?,
        APP_PERSON=? 
    where
        id=?

//locate them from DB

em.flush(); em.clear();

Applicant applicant3 = em.find(Applicant.class, applicant.getId());

Borrower borrower3 = em.find(Borrower.class, borrower.getId());

assertEquals(applicant.getId(), borrower3.getApplication().getId());

assertEquals(borrower.getId(), applicant3.getBorrower().getId());

-
    select
        applicant0_.id as id1_12_0_,
        applicant0_.APP_BORROWER as APP_BORR2_12_0_,
        applicant0_.APP_PERSON as APP_PERS3_12_0_,
        borrower1_.BORROWER_ID as BORROWER1_15_1_,
        borrower1_.endDate as endDate2_15_1_,
        borrower1_.startDate as startDat3_15_1_,
        person2_.PERSON_ID as PERSON_I1_27_2_,
        person2_.firstName as firstNam2_27_2_,
        person2_.lastName as lastName3_27_2_,
        person2_.phone as phone4_27_2_,
        person2_.PERSON_PHOTO as PERSON_P5_27_2_
    from
        ORMREL_APPLICANT applicant0_
    left outer join
        ORMREL_BORROWER borrower1_
            on applicant0_.APP_BORROWER=borrower1_.BORROWER_ID
    inner join
        ORMREL_PERSON person2_
            on applicant0_.APP_PERSON=person2_.PERSON_ID
    where
        applicant0_.id=?
-Applicant@1a531422, ctor()
-Borrower@7a388990, ctor()
-Person@13213f26, ctor()