Update MongoDb data inside a field - node.js

Question

I have a MongoDb Database with a collection called rooms. In rooms, I want to search for a particular object by the roomId property. I want to update the array contents in the found object. For instance, initially, before making a request to that endpoint, the desired data looks like this:
{
available: true,
_id: 60817a403170bf49185c7db7,
player1: "Jack",
player2: "Adam",
roomId: "ABCDE",
pieces: [
{
point: [6, 0],
player: "1",
type: "P"
},
...
],
__v: 0
}
After making a request like http://localhost:8000/room/ABCDE?x1=6&y1=0&x2=4&y2=0, the data in mongodb should update to
{
available: true,
_id: 60817a403170bf49185c7db7,
player1: "Jack",
player2: "Adam",
roomId: "ABCDE",
pieces: [
{
point: [4, 0], /* DATA UPDATED */
player: "1",
type: "P"
},
...
],
__v: 0
}
This is my api.js file, what should the code be in the comments in order to execute this?
const express = require('express');
const GameRoom = require('../models/room');
const router = express.Router();
router.put('/room/:id', (req, res, next) => {
GameRoom.findOne({roomId: req.params.id})
.then(data => {
const pieces = data.pieces;
for (let i = 0; i < pieces.length; i++) {
if (pieces[i].point[0] === parseInt(req.query.x1) &&
pieces[i].point[1] === parseInt(req.query.y1)) {
pieces[i].point = [req.query.x2, req.query.y2];
break;
}
}
// Take the modified pieces array and update it
}).catch(next);
});

Answer 1

You can use $[<identifier>] to find and update the points:
GameRoom.updateOne(
{ roomId: req.params.id },
{ $set: { "pieces.$[el].point.0": req.query.x2, "pieces.$[el].point.1": req.query.y2 }},
{ arrayFilters: [ { "el.point.0": req.query.x1, "el.point.1": req.query.y1 } ]}
);
Or if you just want to update the first pieces that match the condition then you can use $elemMatch with $ operator:
GameRoom.updateOne(
{
roomId: req.params.id,
pieces: {$elemMatch: {"point.0": req.query.x1, "point.1": req.query.y1}}}
},
{ $set: {"pieces.$.point.0": req.query.x2, "pieces.$.point.1": req.query.y2} }
);