@PrimaryKeyJoinColumn doesn't works as expected with a one to one mapping in Hibernate

Question

In this tutorial, the author takes into consideration-

@Entity
@Table
public class Stock implements Serializable {

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column
    private Integer stockId;

    @Column
    private String stockCode;

    @Column
    private String stockName;

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "stock")
    private StockDetail stockDetail;

    // getters and setters
}

---

@Entity
@Table
public class StockDetail implements java.io.Serializable {


    @Id
    @GeneratedValue(generator = "generator")
    @GenericGenerator(  name = "generator", 
                        strategy = "foreign", 
                        parameters = @Parameter(name = "property", value = "stock"))
    @Column
    private Integer stockId;

    @OneToOne(fetch = FetchType.LAZY)
    @PrimaryKeyJoinColumn
    private Stock stock;
    // getters and setters
}

with the hibernate.cfg.xml file having the entry to auto create the tables which are shown below-

<property name="hbm2ddl.auto">create</property> 

---

 CREATE TABLE stock
(
  stockid serial NOT NULL,
  stockcode character varying(255),
  stockname character varying(255),
  CONSTRAINT stock_pkey PRIMARY KEY (stockid)
)

and

CREATE TABLE stockdetail
(
  stockid integer NOT NULL,
  compdesc character varying(255),
  compname character varying(255),
  listeddate date,
  remark character varying(255),
  CONSTRAINT stockdetail_pkey PRIMARY KEY (stockid)
)

You see that there is no foreign key constraint on stockdetail table. Why?

If I change @PrimaryKeyJoinColumn to @JoinColumn

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn
    private Stock stock;

then the table generated by hibernate in this case -

CREATE TABLE stockdetail
(
  stockid integer NOT NULL,
  compdesc character varying(255),
  compname character varying(255),
  listeddate date,
  remark character varying(255),
  stock_stockid integer,
  CONSTRAINT stockdetail_pkey PRIMARY KEY (stockid),
  CONSTRAINT fk9rrwxdqh1fjcoo2usdix4qoiw FOREIGN KEY (stock_stockid)
      REFERENCES stock (stockid) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION
)

which is absolutely correct as expected?

Please suggest?

Answer 1

Update your code with this.

@OneToOne(fetch = FetchType.LAZY,optional=false)
@PrimaryKeyJoinColumn
private Stock stock;

Reference: https://forum.hibernate.org/viewtopic.php?f=9&t=956345