Relation between entities/models

[AurelienPillevesse]

I have a question about the organization between the entities/models. I can see that all (or most) relationships are done by identifiers.

Why aren't relations made between entities directly instead of using string identifiers?

[Sephster]

The database implementation is largely up to you. If you want to add relations to enforce referential integrity, you should be able to afaik

[AurelienPillevesse]

Thanks for your answer