Hi :wave: What do you think about making a JPA entity `data class` ? I know that equals and hashcod...

# server

[Łukasz Pięta]

Hi 👋

What do you think about making a JPA entity data class ? I know that equals and hashcode need to be overridden then, but what about "The entity class must not be final*"* rule from JPA Specification? It can be easily solved by all-open compiler plugin as well. However it looks weird in the bytecode

@javax.persistence.Entity public open data class

I already found an issue https://youtrack.jetbrains.com/issue/KT-34568/All-open-plugin-does-not-support-data-classes and the answer

breaking data class contracts will eventually bring more harm than good.

but I wonder what are the exact consequences of breaking the data class contract

[Jonas TM]

Have a look at this webinar from yesterday. It also covers data class and JPA

https://www.youtube.com/watch?v=cjpSaeIfq9M▾

[Łukasz Pięta]

@Jonas TM Thanks for the link! However it wast just said "not to use data class for `@Entity`", but no further analysis was made 😕
I already knew that data class causes problems to the JPA and there is a more detailed video from jetbrains explaining that further

https://www.youtube.com/watch?v=a_6V8xwiv04&ab_channel=KotlinbyJetBrains▾

but still I don't know what might be the consequences of breaking the data class contract in bytecode, even though I know there is no sense to use data class for entity at all