Getting null when trying to return only single object and not array in graphql for neo4j db

Question

I want to return a single object(not array).The graphql server is returning null when i try to return single object.But seems to work fine while trying to return an array.

Here is my schema example:

type Author{
     authorID: String
     label: String 
     posts: [Post]
   }

 type Post {
      postID: String
      label: String
      author: Author
 }

type Query {
       getAuthorById (authorID: String!): Author #-> this does not work
       getAuthorById (authorID: String!): [Author] #-> this works
 }

But when I try to run this query "getAuthorById (authorID: String!)",I am getting the following result:

 {
  "data": {
    "getAuthorById": {
            "label": null,
            "authorID": null
   }
 }

However,it seems to work only if i try to return an array (when I try to change the schema for type query like this):

type Query {
      getAuthorById (authorID: String!): [Author]
 }

Here is my resolver.js:

Query: {
 getAuthorById(_, params) {

   let session = driver.session();

   let query = `MATCH (a:Author{ authorID: $authorID})  RETURN a ;`

      return session.run(query, params)

     .then( result => {
       return result.records.map( record => {
         return record.get("a").properties
       }
     )
   }
  )
 },

}

What I need is to return a single object like this: getAuthorById (authorID: String!): Author

// Instead of array like this-> getAuthorById (authorID: String!): [Author]

so,could someone let me know what am i doing wrong here ? All I need is to return single object and not array .... Thanks in Advance

William Lyon · Accepted Answer · 2017-08-24 18:32:19Z

1

The problem is in your resolver, specifically you are returning the result of result.records.map() from the resolver. map() evaluates to an Array (applying the inner function to each element of result in this case.

Instead you can just grab the first Record in the Result stream:

.then( result => {
   return result.records[0].get("a").properties
   }
 )

answered Aug 24, 2017 at 18:32

William Lyon

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2 Comments

Code Reactor Over a year ago

Thanks @William, it worked...Lastly, could you please point out any specific link where I could learn more regarding these properties and neo4j documentation cause I have read most of the neo4j blogs, but still never got a hold of useful insight as you provided. Thanks again !

William Lyon Over a year ago

Great! Docs for Neo4j JavaScript driver are here: neo4j.com/docs/api/javascript-driver/current

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