Query wont return data from relationship - mongodb

Question

I'm following this video series.
Here i have problem with getting data about user who created the event in following script
here's my app.js
const express = require('express');
const bodyParser = require('body-parser');
const graphqlHttp = require('express-graphql')
const { buildSchema } = require('graphql');
const mongoose = require('mongoose');
const bcrypt = require('bcrypt');
const Event = require('./models/event');
const User = require('./models/user');
const app = express();
const conString = `mongodb+srv://${process.env.MONGO_USER}:${process.env.MONGO_PASSWORD}#clusterpl-qiufl.mongodb.net/${process.env.MONGO_DB}?retryWrites=true&w=majority`
app.use(bodyParser.json());
app.use(
'/graphql',
graphqlHttp({
schema: buildSchema(`
type Event {
_id: ID!
title: String!
description: String!
price: Float!
date: String!
creator: User!
}
type User {
_id: ID!
email: String!
password: String!
createdEvents: [Event!]
}
input UserInput {
email: String!
password: String!
}
input EventInput {
title: String!
description: String!
price: Float!
date: String!
}
type RootQuery {
events: [Event!]!
}
type RootMutation {
createEvent(eventInput: EventInput): Event
createUser(userInput: UserInput): User
}
schema {
query: RootQuery,
mutation: RootMutation
}
`) ,
rootValue: {
events: () => {
return Event.find().populate('creator')
.then(events => {
console.log(events)
return events.map(event => {
console.log(event)
return {
...event._doc,
_id: event.id
};
});
})
.catch(err => {
throw err;
})
},
..
},
graphiql: true
})
);
mongoose.connect(conString, {useNewUrlParser: true}).then(
() => {console.log('Success !')},
err => { console.log(err) }
)
app.listen(3000);
user.js and event.js
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const userSchema = new Schema({
email: {
type: String,
required: true
},
password: {
type: String,
required: true
},
createdEvents: [
{
type: Schema.Types.ObjectId,
ref: 'Event'
}
]
});
module.exports = mongoose.model('User', userSchema)
const mongoose = require('mongoose');
const Schema = mongoose.Schema
const eventSchema = new Schema({
title: {
type: String,
required: true
},
description: {
type: String,
required: true
},
price: {
type: Number,
required: true
},
date: {
type: Date,
required: true
},
creator: [
{
type: Schema.Types.ObjectId,
ref: 'User'
}
]
});
module.exports = mongoose.model('Event', eventSchema);
once i submit this graphql query
query{
events {
creator {
email
}
}
}
returns "message": "Cannot return null for non-nullable field User.email.",
I'm completly new to graphql and any answer would be much appreciate.

Answer 1

maybe this might helps someone else, i don't know what happens there but i got expected results, by adding
const user = userId => {
return User.findById(userId).then(user => {
return { ...user._doc, _id: user.id };
})
.catch(err => {
throw err;
});
}
method and used it in event resolver function like this
events: () => {
return Event.find()
.populate('creator')
.then(events => {
return events.map(event => {
console.log('ev',event._doc)
return {
...event._doc,
_id: event.id,
// creator: {
// ...event._doc.creator._doc,
// _id: event._doc.creator.id
// }
creator: user.bind(this, event._doc.creator)
};
})
})
.catch(err => {
throw err;
})
},