How to create relationships on non id fields is not clear

Since Watermelon auto assigns the id field, I’m trying create a relationship between two models on non ‘id’ fields as per their relationship on the remote resource. the example would be:

class Pledge extends Model {
  static table = 'pledges'
  static associations = {
    profiles: { type: 'belongs_to', key: 'id_profile' },
  }

  @field('pledge_id') pledgeId
  @field('owner') owner
  @field('amount') amount

  @relation('profiles', 'id_profile') profile

}

class Profile extends Model {
  static table = 'profiles'
  static associations = {
    pledges: { type: 'has_many', foreignKey: 'id_profile' }
  }

  @field('addr') addr
  @field('type') type
  @field('name') name
  @field('id_profile') idProfile

  @children('pledges') pledges

When I try to create the Pledge on pledge.profile.set(profile.id) the profile is not set and id_profile is “0” when it should have a value.

So this is two questions.

1. Would this be the ideal way to model this relationship in Watermelon?
2. Is this the correct way to create the Pledge record?

[bgits]

@bgits All right, so let me get this straight:

you have a Pledge record, which has its id (which is a local-only Watermelon ID), and its pledgeId (which is what the remote server assigns to it). And analogous with Profile. Correct?

This is kind of a problem for Watermelon at this moment, since Watermelon assumes all relation IDs are to id fields — and that local and remote IDs are consistent.

See this issue for the discussion on how to deal with local and remote IDs: #216 — if you can, for example, normalize IDs to all be local IDs during synchronization, all will be good.

Another solution (at least a partial one) is to add a local id field to relation/immutableRelation decorator. See @esbenp’s thread here: #219 — this is an analogous situation. If you’d like to contribute to that, that would be great.

Let me know if this clears up the situation and what you choose to do in your case 😃

For now I resorted to creating these relationships on the id fields during the data import and keeping their remote id’s on {model}Id field. I will see if this degrades into something problematic for me.

[KrisLau]

@radex Is it still not possible to create a relation on non _id fields?