Linking collections in GraphQL resolver - node.js

Question

I am trying to join two collections in GraphQL query.
My data is as follows:
Cruises:
[
{
"cruiseID" : "00001",
"title" : "title 1",
"description" : "desc 1",
"startDate" : 20150820,
"endDate" : 20150827,
"numDays" : 8,
"startPort" : "Juneau, Alaska",
"roomTypes" : [
{"roomID" : "IPD"},
{"roomID" : "SDS"}
]
}, {
"cruiseID" : "00002",
"title" : "title 1",
"description" : "desc 2",
"startDate" : 20150710,
"endDate" : 20150724,
"numDays" : 14,
"startPort" : "San Diego",
"roomTypes" : [
{"roomID" : "IPD"},
{"roomID" : "SJS"},
{"roomID" : "SDS"}
]
}
]
Rooms:
[
{
"roomID": "IPD",
"roomDetails": {
"roomType": "IPD aaaaa",
"title": "aaaa",
"description": "ddddd",
"maxOccupants": 2
},
"capacity": [
{"cruiseID": "00001", "total": 21, "available": 20},
{"cruiseID": "00002", "total": 31, "available": 30}
]
},
{
"roomID": "SJS",
"roomDetails": {
"roomType": "SJS aaaa",
"title": "aaaaa",
"description": "aaaaa",
"maxOccupants": 4
},
"capacity": [
{"cruiseID": "00001", "available": 27},
{"cruiseID": "00002", "available": 27}
]
},
{
"roomID": "SDS",
"roomDetails": {
"roomType": "SDS aaa",
"title": "sssss",
"description": "sssssss",
"maxOccupants": 4
},
"capacity": [
{"cruiseID": "00001", "available": 20},
{"cruiseID": "00002", "available": 20}
]
}
]
My GraphQL schema:
type Query {
Cruises: [Cruise]
}
type RoomDetails {
roomType: String
title: String
description: String
maxOccupants: Int
}
type Capacity {
cruiseID: String
total: Int
available: Int
}
type Room {
roomID: String
roomDetails: RoomDetails
capacity: [Capacity]
}
type Cruise {
_id: ID
cruiseID: String
title: String
description: String
startDate: Int
endDate: Int
numDays: Int
startPort: String
roomTypes: [Room]
}
My GraphQL resolver where I try to print details for roomTypes by reading them from rooms collection:
const Query = {
Cruises: async () => {
data = await db.collection('cruises').find().toArray().then(res => { return res });
return data
}
}
const Cruise = {
roomTypes: async (root) => {
data = await db.collection('rooms').find({'roomID': 'SDS'}).toArray().then(res => { return res });
// prints OK
logger.debug(`root.roomTypes.roomID': ${JSON.stringify(root.roomTypes[1].roomID)}`);
// undefined
logger.debug(`root.roomTypes.roomID': ${JSON.stringify(root.roomTypes.roomID)}`);
// prints OK
logger.debug(`root.startPort': ${root.startPort}`);
return data
}
}
module.exports = {
Query,
Cruise
}
I can't find a proper join between Cruises and Rooms.
Hardcoded {'roomID': 'SDS'} works OK i.e. shows proper output.
However, I can't find a way to properly pass roomID from Cruises to the find filter. Any hints?
UPDATE:
When I implement the resolver life this:
const Cruise = {
roomTypes: async (root) => {
data = await db.collection('rooms').find({'capacity.cruiseID': root.cruiseID}).toArray().then(res => { return res })
//data = await db.collection('rooms').find().toArray().then(res => { return res })
return data
}
}
I get the data back (roomTypes fully resolved) but, it doesn't do any filtering/joining actually.
Here's what I get (edited with some rubbish data so it's shorter):
"data": {
"Cruises": [
{
"cruiseID": "00001",
"title": "and",
"startDate": 20150820,
"endDate": 20150827,
"numDays": 8,
"startPort": "Juneau, Alaska",
"roomTypes": [
{
"roomID": "IPD",
"roomDetails": {
"roomType": "asd",
"title": "and",
"description": "asdr",
"maxOccupants": 2
},
"capacity": [
{
"cruiseID": "00001",
"total": 21,
"available": 20
},
{
"cruiseID": "00002",
"total": 31,
"available": 30
}
]
},
{
"roomID": "OPD",
"roomDetails": {
"roomType": "ad",
"title": "and",
"description": "asdr",
"maxOccupants": 2
},
"capacity": [
{
"cruiseID": "00001",
"total": null,
"available": 30
},
{
"cruiseID": "00002",
"total": null,
"available": 30
}
]
},
{
"roomID": "SDD",
"roomDetails": {
"roomType": "asd",
"title": "and",
"description": "and",
"maxOccupants": 2
},
"capacity": [
{
"cruiseID": "00001",
"total": null,
"available": 25
},
{
"cruiseID": "00002",
"total": null,
"available": 25
}
]
},
{
"roomID": "SD2",
"roomDetails": {
"roomType": "asd",
"title": "and",
"description": "Fast",
"maxOccupants": 4
},
"capacity": [
{
"cruiseID": "00001",
"total": null,
"available": 22
},
{
"cruiseID": "00002",
"total": null,
"available": 22
}
]
},
{
"roomID": "SJS",
"roomDetails": {
"roomType": "asd",
"title": "and",
"description": "Tasdr",
"maxOccupants": 4
},
"capacity": [
{
"cruiseID": "00001",
"total": null,
"available": 27
},
{
"cruiseID": "00002",
"total": null,
"available": 27
}
]
},
{
"roomID": "SDS",
"roomDetails": {
"roomType": "asd",
"title": "and",
"description": "Tase",
"maxOccupants": 4
},
"capacity": [
{
"cruiseID": "00001",
"total": null,
"available": 20
},
{
"cruiseID": "00002",
"total": null,
"available": 20
}
]
}
]
},
instead of only having 2 room types (IPD, SDS) listed for cruiseID 00001 as per the entries in Cruises collection.

Answer 1

This is how I finally did it. It's not the cleanest code/solution but it does the job.
const Cruise = {
roomTypes: async (root) => {
let rooms = root.roomTypes;
allRooms = await db.collection('rooms').find().toArray().then(res => { return res });
rooms.forEach(room => {
let currentRoomID = room.roomID;
currentRoom = allRooms.filter(function(r) {
return r.roomID === currentRoomID;
});
currentRoomCapacity = currentRoom[0].capacity.filter(function(c) {
return c.cruiseID === root.cruiseID;
});
room.roomDetails = currentRoom[0].roomDetails
room.capacity = currentRoomCapacity
});
return rooms;
}
}