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

Hi Steve, I know that a bidirectional one-to-one association works properly with Product#productInfo on the "mappedBy" side, and ProductInfo#product on the owning side. With that mapping, ProductInfo#product is a ManyToOne that is a "logical" OneToOne. I agree that is the more natural way to map this association, but this use case is for a unidirectional one-to-one. What I'm seeing in the debugger for this unidirectional one-to-one association, Product#productInfo, is that it is OneToOneType with: * #foreignKeyType == ForeignKeyDirection.TO_PARENT * #referenceToPrimaryKey == true Both of these seem wrong to me for a unidirectional one-to-one, but maybe I'm missing something. I should mention that, in this particular case, no foreign key is generated. Even so, ForeignKeyDirection.TO_PARENT, means that Hibernate assumes that the foreign key is defined in ProductInfo, not Product, doesn't it? If the foreign key were in ProductInfo, then it would make sense that #referenceToPrimaryKey == true. I want to make sure that I understand what should be expected behavior for this use case. Since Product#productInfo is a unidirectional one-to-one, I would have expected that OneToOneType would have: * #foreignKeyType == ForeignKeyDirection.FROM_PARENT (with foreign key column Product#id) * #referenceToPrimaryKey == false (since it references non-PK column ProductInfo#productId) Also, Product#id will always be non-null, but that doesn't mean that there is a non-null association with ProductInfo. It seems that Hibernate should complain when an association cannot be found, unless the association is annotated with @NotFound(NotFoundAction.IGNORE). Does this sound right to you? Thanks, Gail On Thu, Mar 8, 2018 at 11:22 AM, Steve Ebersole <steve(a)hibernate.org&gt; wrote: