Can @GenerateValue be used with non primary key attributes?

Question

I am confused as everywhere it is mentioned to use @GenerateValue only with @Id.

But: can it be used with non primary key attributes?

Answer 1

The JPA specification document provides an important hint that you should not do so, see section 11.1.20, on page 449:

Footnote [110]: Portable applications should not use the GeneratedValue annotation on other persistent fields or properties.

Here, ”other“ refers to fields or properties of an Entity that are not annotated with @Id:

The GeneratedValue annotation may be applied to a primary key property or field of an entity or mapped superclass in conjunction with the Id annotation.

Hence, I would conclude that most, if not all, persistence provider implementations might not support your intended (special) use case.