Passing Multiple Arguments to GraphQL Query

Alex Lynham picture Alex Lynham · Sep 27, 2017 · Viewed 11.6k times · Source

First thing

Appreciate this may be a bit of a stupid question, but I'm working with GraphQL having come from the RDF/Linked Data world and having a lot of trouble getting my head around how I would return a set. Essentially I want something where I could select, let's say a list of Characters (using the examples from the GraphQL docs) via their id. In SPARQL I'd be using the VALUES clause and then binding, something like:

VALUES { <http://uri/id-1> <http://uri/id-2> <http://uri/id-3> }

I'd assume something like this would be what I'd want (pseudocode)

{
  human(id: ["1", "2", "3", "4", "5"]) {
    name
    height
  }
}

Aliases kind of do what I want, but I don't want to have to specify in advance or manually what the different named return values are - I want to say in my code pass a list of IDs:

[1 2 3 4 5]

...and have a query that could accept that array of IDs and return me results in a predictable non-scalar shape as per the pseudo-query above.

Second thing

I'm also assuming that it's in fact not possible to have a query resolve to either a Human or [Human] - that it has to be one or the other? No biggie if so, I'd just settle for the latter... but I think I'm just generally quite confused over this now.

Answer

bora89 picture bora89 · Sep 27, 2017

First you need to extend you query by adding a "humans":

extend type Query {
  humans(listId: [String!]): [Human!]
  human(id: ObjID!): Human
}

Second - write a resolver for it.

Query: {
  humans(root, {listId}, { Human }) {
    return Human.fillAllByListId(listId);
  },
  ...
},

List of IDs could be passed as follows: pass list of IDs