Loading relational data in GraphQL & MongoDB

Question

This is my schema:

type User {
    _id: ID!
    username: String
    email: String!
    firstName: String
    lastName: String
    avatar: String
    createdAt: Date!
    updatedAt: Date!
}

type Tweet {
    _id: ID!
    text: String!
    user: User!
    favoriteCount: Int!
    createdAt: Date!
    updatedAt: Date!
}

and here's my Tweet model:

import mongoose, { Schema } from 'mongoose';

const TweetSchema = new Schema({
    text: {
        type: String,
        minLength: [5, 'Your tweet is too short.'],
        maxLength: [144, 'Your tweet is too long.']
    },
    user: {
        type: Schema.Types.ObjectId,
        ref: 'User'
    },
    favoriteCount: {
        type: Number,
        default: 0
    }
}, { timestamps: true });

export default mongoose.model('Tweet', TweetSchema);

the above GraphQL schema is served by express like this:

import { graphqlExpress } from 'apollo-server-express';
import { makeExecutableSchema } from 'graphql-tools';

import typeDefs from '../graphql/schema';
import resolvers from '../graphql/resolvers';

const schema = makeExecutableSchema({
    typeDefs,
    resolvers
});

const app = express();
app.use(
    '/graphql', 
    graphqlExpress(req => ({ 
        schema
    }))
);

I use the following code to mock up some users and tweet using faker like this:

https://pastebin.com/raw/kJ9m8KjR

When the whole thing runs, I can see the mongodb is populated with dummy tweets linked to a user like this:

but when I query this via GraphiQL, the user info is not coming through:

Any ideas?

hi. here it is the tweet resolvers: pastebin.com/raw/tGSixdMe — Latheesan

Daniel Rearden Daniel Rearden · Accepted Answer · 2017-08-20T20:56:03

Your resolver gets the Tweets like this:

Tweet.find({}).sort({ createdAt: -1 });

If you check out the docs, you'll notice you need to tell mongoose to replace the id reference with an actual document by using populate:

Tweet.find({}).populate('user').sort({ createdAt: -1 });

Loading relational data in GraphQL & MongoDB

1 Answers