Polymorphic entities

[greenrobot]

Allow subclassing of entities.

Affects:

• Box: should baseBox.get(subclassId) return a subclass entity? Probably so.
• Queries: Querying for the base class should return all sub classes.
• Relations: if a relation references a base class, actual objects may also be sub classes.

[Miha-x64]

Creating schema for such entities looks quite complicated. How database should handle object of previously unknown subclass with many new fields?
Maybe Kotlin sealed classes may help: all allowed subclasses are known at compile-time.

[dbacinski]

I would put it at the end of backlog, we can live without polimorfic types.

[YuriDenison]

• for Kotlin sealed classes.

[greenrobot]

@YuriDenison Can you give an example why one would used sealed classes as entities?

[YuriDenison]

Simple example

sealed class Destination {
  abstract val createdAt: Long

  data class City(...) : Destination()
  data class Hotel(...): Destination()
}

It would be nice to be able to create Destination box and make queries like 'get all destinations ordered by createdAt'

[Miha-x64]

[Offtop] Why do you need data modifier here?

[motis10]

What about this issue? any updates?

[motis10]

So important to the correct usage of the library my friends. You have to fix it :)