when `.copy()`ing a data class that inherits from ...

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[dG]

when `.copy()`ing a data class that inherits from an open class, the properties/constructor values from the open class are not copied. I understand why, but what is the proper way to do this then?

[spand]

Make the base class an interface

[dG]

Seems I cannot use (JPA) annotations on fields in an interface, though

[spand]

Too bad

[spand]

You can always implement your own copy() method if that is all you wanted from the data class concept

[spand]

Maybe if you leave the base class properties abstract ? https://stackoverflow.com/a/54418002/422924

[diesieben07]

data classes for JPA are usually a bad idea anyways, see e.g. https://vladmihalcea.com/how-to-implement-equals-and-hashcode-using-the-jpa-entity-identifier/