Relay / GraphQL'如何解决'有效吗？

Question

I am trying out Relay and GraphQL . When I am doing the schema I am doing this:

let articleQLO = new GraphQLObjectType({
  name: 'Article',
  description: 'An article',
  fields: () => ({
    _id: globalIdField('Article'),
    title: {
      type: GraphQLString,
      description: 'The title of the article',
      resolve: (article) => article.getTitle(),
    },
    author: {
      type: userConnection,
      description: 'The author of the article',
      resolve: (article) => article.getAuthor(),
    },
  }),
  interfaces: [nodeInterface],
})

So, when I ask for an article like this:

{
  article(id: 1) {
    id,
    title,
    author
  }
}

Will it do 3 queries to the database? I mean, each field has a resolve method ( getTitle , getAuthor , etc.) which does a request to the database. Am I doing this wrong?

This is an example of getAuthor (I use mongoose):

articleSchema.methods.getAuthor = function(id){
  let article = this.model('Article').findOne({_id: id})
  return article.author
}

Answer 1

If the resolve method is passed the article , can't you just access the property?

let articleQLO = new GraphQLObjectType({
  name: 'Article',
  description: 'An article',
  fields: () => ({
    _id: globalIdField('Article'),
    title: {
      type: GraphQLString,
      description: 'The title of the article',
      resolve: (article) => article.title,
    },
    author: {
      type: userConnection,
      description: 'The author of the article',
      resolve: (article) => article.author,
    },
  }),
  interfaces: [nodeInterface],
})

Since Schema.methods in Mongoose defines methods on the model , it wouldn't take an ID for the article (because you call it on an article instance). So, if you wanted to keep the method, you would just do:

articleSchema.methods.getAuthor = function() {
  return article.author;
}

If it was something you need to look up eg in another collection, then you'd need to do a separate query (assuming you're not using refs):

articleSchema.methods.getAuthor = function(callback) {
  return this.model('Author').find({ _id: this.author_id }, cb);
}