Let's say I have a

posts

query which is retrieved by an API call. The

comments

field for every

post

is retrieved by another API call, the requests are batched with dataloader. Is it possible to filter the returned

posts

based on the

comments

field (e.g. only return

posts

with

comments

)? My problem is that the

comments

field is only available after I returned the promise from the

posts

query. Is it possible to filter/transform the returned data after every related promises resolved?

I think that the section of docs you are looking for is this:- https://www.prisma.io/docs/reference/prisma-api/queries-ahwee4zaey#querying-data-across-relations I think you should be able to query by nested relations with the generated API. Did you already give it a go in playground?

It works in Prisma, but in my example both

posts

and

comments

are retrieved via an external API call (e.g. `fetch('someapi/posts'). So initially the

posts

array can't be filtered by the

comments

because they're retrieved separately. E.g.:

// Posts.js

export const Posts = {
  comments: (parent, args, ctx, info) => {
    return ctx.externalApi.getCommentsForPost(parent.id)
  }
}

// Query.js

async posts(parent, args, ctx, info) {
  const posts = ctx.externalApi.getPosts()
  // ideally I'd be able to filter the posts
  // based on the comments property
  // but the prop is not there, it'll be
  // populated by Posts() above
  return posts
}

So you want to filter it in posts resolver? Or pass it the external API for filtering?

I want to filter the returned

posts

based on their

comments

- the problem is that the

comments

are not available when I receive the

posts

. I have to return the promise (which will resolve to the posts array) in order for the

comments

resolver function to run. So somehow I want to modify the results after

return

...

You don't have to return promise from resolver, you can use await to get the posts in a variable and fetch the respective comments

ah, you're right, I thought I can't use dataloader that way but it works. Thanks!

Can you please persist this in form of an issue? https://github.com/prismagraphql/graphql-yoga Sounds like a good use case, we can brainstorm on that later!