Unable to return a list of documents via an index

[edhog]

Hi, I’m bumbling my way through adding a back-end to my site and have decided to get acquainted with graphQL. I may be structuring things totally the wrong way, however from following some tutorials I have a React front-end (hosted on Vercel), so I have created an api folder in my app to make use of Vercel’s serverless functions. I’m using Apollo server with Fauna as the database.

I’ve successfully been able to return an entire collection via my API. However, now I wish to be able to return the collection sorted by my id field.

To do this I created an index which looks like this:

{
  name: "sort_by_id",
  unique: false,
  serialized: true,
  source: "my_first_collection",
  values: [
    {
      field: ["data", "id"]
    },
    {
      field: ["ref"]
    }
  ]
}

I then was able to call this via my api and get back and array, which simply contained the ID + ref, rather than the associated documents. I also could only console log it, I assume because the resolver was expecting to be passed an array of objects with the same fields as my typedefs. I understand I need to use the ref in order to look up the documents, and here is where I’m stuck. An index record looks as follows:

[1, Ref(Collection("my_first_collection"), "352434683448919125")]

In my resolvers.js script, I am attempting to receive the documents of my sorted index list. I’ve tried this:

async users() {
    const response = await client.query(
            q.Map(
                q.Paginate(
                    q.Match(
                        q.Index('sort_by_id')
                    )
                ),
                q.Lambda((ref) => q.Get(ref))
            )
        )

        const res = response.data.map(item => item.data);
        return [... res]
}

Which results in a “BadRequest invalid expression” error.

I’m unsure if the problem is with how I’ve structured my index, or if it is with my code, I’d appreciate any advice.

[ewan]

Hi @edhog !

You are in the ballpark of success, but there is a mismatch between your index and your query.

Your index returns a tuple, the data.id field in a matching document and the document’s ref.

Your query uses:

q.Lambda((ref) => q.Get(ref))

which accepts a single value.

Instead, use:

q.Lambda(["id", "ref"], q.Get(q.Var("ref")))

[edhog]

Hi @ewan that did the trick, thanks so much!