docs: clarify dataloader usage with nestjs about mikro-orm HOT 4 CLOSED

dataloaders dont work on em.find at all, they are only for reference and collection loading.

not sure how that could be combined with nest, any ideas @darkbasic?

edit: I guess something like this should work:

  @ResolveField(() => User)
  public async author(@Parent() book: Book) {
    return book.author.load();
  }

note that you need to use the Reference wrapper for your relation:

@ManyToOne(() => User, { ref: true })
public author: Ref<User> // Ref, not Rel

edit 2: moving back to the main repo, as the dataloader docs would indeed deserve more details about this

from mikro-orm.

Btw there is apparently one alternative if you dont want to use the Ref wrapper - you can create it via wrap helper dynamically and return that from your resolver:

  @ResolveField(() => User)
  public async author(@Parent() book: Book) {
    return wrap(book.author).toReference().load();
  }

(at least that's what one user recently said worked for them)

I would still rather suggest using it - type safe relations (Loaded type) depend on this too.

from mikro-orm.

Thank you for the quick response, I've tried here and just works!

from mikro-orm.

hope this makes it clearer, PR welcome if you see more room for improvements

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