Rather than using the implicit Orgs id, I want to reference on the Orgs (and Users) uid, which is a unique string. What’s the proper syntax for defining OrgMembership in that case? IntelliJ complains that

val org by Org referencedOn OrgMemberships.orgId

has a type mismatch, where it expects a

Column<EntityId<Int>>

but gets a

Column<EntityId<String>>

. How do I tell OrgMembership to use that string?

Why then you use IntIdTable, instead of IdTable<String>() ? Please look on declaration of UUIDTable class.

But if I use that, then I lose the implicit int id as PK on the Orgs table, right? What I was hoping to do was to use a column that is unique but is not a PK as an FK reference, which is something MySQL supports…

It's not so easy to implement with some "quick-fix", because it requires to rework current references implementation. I created issue https://github.com/JetBrains/Exposed/issues/282 to support it in future

Gotcha. Figured it might still be a missing feature. Didn’t think to look through the open issues.