[hibernate-dev] Is unidirectional one-to-one referencing a non-primary key valid

[Gail Badner]

Hi,

This is an unusual mapping. My gut feeling is that it is not a valid
mapping, but I don't see anything in the spec that would indicate it is
invalid.

Here is the mapping:

@Entity
public class Product {
   @Id
   @Column(name = "id")
   private int id;

   @OneToOne(cascade = CascadeType.ALL)
   @JoinColumn(name = "id", referencedColumnName = "productId",
insertable = false, updatable = false)
   private ProductInfo productInfo;

}

@Entity
public class ProductInfo{
   @Id
   private int id;

   @Column(name = "productId", unique = true, updatable = false)
   private int productId;
}

Hibernate ignores referencedColumnName = "productId" and assumes that
Product and ProductInfo share the same ID value.
When the IDs are not the same, Product#productInfo will be null.

It seem to me that the foreign key column should be
ProductInfo#productId and should reference Product#id, but this
doesn't make sense
for a unidirectional one-to-one owned by Product.

IMO, a bidirectional @OneToOne with ProductInfo owning the association
would make more sense.

A test case can be found at [1]

Is the mapping invalid, or is this a bug in Hibernate?

Thanks,
Gail
[1] https://github.com/gbadner/hibernate-test-case-templates/commit/d806d4ef5cf35da85efc51ce70c5e0648ce89006