How to get an array or list as result from a graphql query?

Question

Hello I am new to graphql and I was wondering if it is possible to create a root query in my schema that will return an array or list as a result.

To be more precise I have created the following type in my schema:

const ResourceType = new GraphQLObjectType({
  name:'Resource',
  fields:()=>({
   id: {type: GraphQLID},
   url: {type: GraphQLString},
   title: {type: GraphQLString},
   author: {type: GraphQLString},
   license:{type: GraphQLString},
   LicenseScore: {type: GraphQLFloat},
 })
});

And I want to query all the resources in my database so that I get their license type and then assign a score according to the license. Is it possible to have a query that gets the license for each resource and returns an array like this: [[id:1209,score:3.5],[1203,4.5]....]?

I have created a mutation that updates the score to the database, here it is:

updateAllLicenses: {
     type: new GraphQLList(ResourceType),
     async resolve(parent,args){
     var licns;
     var scr;
     await Resource.find({}).then(async function(results){
       var num = results.length;
       var scr=0;
       for (var i=0; i<num; i++){
         if (! (results[i].license in licenseScores)){
           scr = 0;
         }
         else{
           scr = licenseScores[results[i].license];
         }
         await Resource.findByIdAndUpdate(results[i].id{LicenseScore:scr});
        }
      });
      return await Resource.find({});
    }
   }

However I was wondering if there is a way to get these scores directly from the query instead of saving them in the database. I tried changing the type to new GraphQLList(GraphQLFloat) and returning an array with the scr values but I get an error in the graphql api saying I have the wrong output type in my mutation.

Are you sure of the syntax of your wanted result: ` [[id:1209,score:3.5],[1203,4.5]....]?? Or should you meant [[id:1209,score:3.5],[id:1203,score:4.5]....]?` — Anas Tiour
No I meant [[1209,3.5],[1203,4.5]] I only wrote the id and score to show the order in which I wish to save the values. Is it possible to get an array as a result from a query? if so what type should the return value have? — gzarnomitrouhotmailcom

Anas Tiour Anas Tiour · Accepted Answer · 2019-06-12T17:58:17

From your schema, it seems to me that you are able to fetch results, as an array of objects, with an output like this:

[
    {
        id: 1,
        license: "value1"
    },
    {
        id: 2,
        license: "value2"
    }
]

If this is all you need, then the approximate query should work:

query Resource {
    id
    url
    license
    licenseScore
}

Once you have your array of objects, you can convert it to an array of arrays, although I would not advise that.

Since you are just getting started in GraphQL, I recommened these resources:

HowToGraphql: clean videos/posts on GraphQL
Apollo Graphql's documentation and blogs. Here is one of the posts on queries

Also, if you want to test your queries and get accustomed to them, use GraphQL Playground

How to get an array or list as result from a graphql query?

1 Answers