JPA join with key transformation

Asked Dec 15 '17 at 07:59

Active Dec 15 '17 at 08:41

Viewed 93 times

It is possible to tranform the primary key before a join with an hibernate annotation in addition to @JoinColumn?

For example:

Table Address(id, countryId) : data -> (1, EN), (2, EN), (3, FR) Table Country(ref, label, language) : data -> (EN1, English, InEnglish), (EN2, Anglais, InFrench), (FR1, French, InEnglish), (FR2, Français, InFrench)

Java:

public class Address {

    @Id
    private Long id;

    @OneToOne (with transformation coutryId+"2" to join)
    private Country countryInFrench;
}

I don't know if I'm clear, do not hesitate to ask question.

edited Dec 15 '17 at 08:41

Rolf ツ

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asked Dec 15 '17 at 07:59

Pred05

Possible duplicate of [JPA/Hibernate Join On Constant Value](https://stackoverflow.com/questions/28818511/jpa-hibernate-join-on-constant-value) – Simon Martinelli Dec 15 '17 at 08:05
I have seen this, but it is possible to transform current value ? if my address.coutryId = FR i want to do the join with FR1 so add 1 to the key before the join. – Pred05 Dec 15 '17 at 08:12
Probably not because this is a bad DB design and such anti patterns are not implemented by JPA – Simon Martinelli Dec 15 '17 at 08:16
i suspected it... but i can't change de DB design... it's too old. – Pred05 Dec 15 '17 at 09:29
I think that you could use a @Formula to represent this conditional – Henrique Fernandes Cipriano Dec 16 '17 at 20:00

JPA join with key transformation

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