[JPA] @OneToOne doesn't set the ID of the relationship owner

Question

Hi,
I have a problem. If there's a cascaded @OneToOne relationship between two entities and the relationship is of type @PrimaryKeyJoinColumn and I persist the inverse side, the owning side does NOT get a proper ID.
Here's an example:
Two tables:
CUSTOMERS
  (ID number(18) not null,
   NAME varchar2(50))
CUSTOMER_DATA
  (ID number(18) not null,
   CREDIT_CARD varchar2(50));The ID columns in both tables are primary keys.
There's a foreign key from CUSTOMER_DATA(ID) to CUSTOMER(ID).
So, I have two entities:
@Entity
@Table(name="CUSTOMERS")
@SequenceGenerator(name="customerIdSeq", sequenceName="CUSTOMERS_SEQ", allocationSize=1)
public class Customer {
     @Id
     @Column(name="ID", nullable=false)
     @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="customerIdSeq")
     private Long id;
     @Column(name="NAME")
     private String name;
     @OneToOne(mappedBy="customer", cascade=CascadeType.ALL)
     private CustomerData customerData;
     public Long getId() {
          return id;
     public void setId(long id) {
          this.id = id;
     public String getName() {
          return name;
     public void setName(String name) {
          this.name = name;
     public CustomerData getCustomerData() {
          return customerData;
     public void setCustomerData(CustomerData customerData) {
          this.customerData = customerData;
@Entity
@Table(name="CUSTOMER_DATA")
public class CustomerData {
     @Id
     private Long id;
     @OneToOne
     @PrimaryKeyJoinColumn
     private Customer customer;
     @Column(name="CREDIT_CARD")
     private String creditCard;
     public Long getId() {
          return id;
     public void setId(Long id) {
          this.id = id;
     public Customer getCustomer() {
          return customer;
     public void setCustomer(Customer customer) {
          this.customer = customer;
     public String getCreditCard() {
          return creditCard;
     public void setCreditCard(String creditCard) {
          this.creditCard = creditCard;
}So, now I try to do the following:
     Customer cust = new Customer();
     CustomerData custData = new CustomerData();
     cust.setCustomerData(custData);
     custData.setCustomer(cust);
     cust.setName("OneToOne");
     custData.setCreditCard("1111-1111-1111-1111");
     em.getTransaction().begin();
     em.persist(cust);
     em.getTransaction().commit();And I get an exception:
     java.sql.SQLException: ORA-01400: cannot insert NULL into ("RMS"."CUSTOMER_DATA"."ID")Why does that happen? I set the relationship properly:
     cust.setCustomerData(custData);
     custData.setCustomer(cust);So, it seems logical that CUSTOMER_DATA.ID should automatically be assigned the same value as the one obtained for CUSTOMER.ID.
What else am I supposed to do?
Best regards,
Bisser

Answer 1

Just tried with the latest TopLink Essentials version (v2.1-b38) from here:
https://glassfish.dev.java.net/downloads/persistence/JavaPersistence.html
The same problem is still present.
It sure looks like a serious deficiency in the JPA spec. Why do I even need to specify a separate @Id basic mapping, if I have specified the @OneToOne and the @PrimaryKeyJoinColumn annotations in the relationship? They should be sufficient for finding out what the ID should be? The ID can be obtained from the inverse entity.