Support value variables for paging params (offset, after, first)

Issues Dgraph
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4

romshark commented :

I think I faced a similar problem working on my dgraph tech-demo. I’m trying to implement pagination and this is the query I assumed to work:

query PostsPage(
  $first: int = 4,
  $id: string = "ce9f834c2fd143e7a0994cd01564d990"
) {
  var(func: eq(Post.id, $id)) {
    p as uid
  }
  posts(
    func: has(Post.id),
    orderasc: Post.id,
    after: val(p),
    first: $first
  ) {
    uid
    Post.id
    Post.title
    Post.contents
  }
}

Unfortunately, it seems like I can’t use p as an argument for after:

": strconv.ParseUint: parsing \"p\": invalid syntax"

I suddenly need 2 roundtrips to get the job done:

  • fetch the uid by id
  • then fetch the page using the uid

This is obviously bad because it could have been done with just a single simple query.
Please correct me if I’m wrong.