findOneAndUpdate: using parent and subdocument id to update

Question

I want to find correct subdocument and change a specific field.

Here are my attempts:

  Book.findOneAndUpdate(
        { _id: req.params.id, chapters: { $elemMatch: { _id: req.params.subid } } },
        { $set: { chapters: { title: 'new title' } } }, { 'new': true }).exec();
    });

Also tried:

  Book.findOneAndUpdate(
    { _id: req.params.id, 'chapters._id': req.params.subid },
    { $set: { 'title': 'new title' } }, { 'upsert': true }).exec();

The first solution removes everything by overwriting it all with a single field, title.

How can I update it correctly?

EDIT:

//Book
    {
        "_id": {
            "$oid": "5ae2f417fe46cf86900af82f"
        },
        "chapters": [
            {                 
                "_id": {
                    "$oid": "5af1b798be6bb05e4427ee65"
                },
               "title": "old title",
               "something": "something"
            },
            //..some more
        ]
    }

Can you give us an example of what a `Book` item looks like? — Explosion Pills, May 11 '18 at 19:16
@ExplosionPills Just added an example of the `Book`, check the question. — ipid, May 11 '18 at 19:27
@Almaju Woah, actually nothing was wrong with it. It take a bit time to fully update it since im forEach:ing it, so when the page was loaded, I didn't see the new result as I assume it was not finished. But after refreshing it again, I did see the change. Thanks for the comment, I wouldn't notice it then. Btw, I recall reading something about async/wait or something. Will that solve the this minor issue to make it wait to load til its fully done? — ipid, May 11 '18 at 19:39

score 6 · Answer 1 · answered May 11 '18 at 19:32

Something like:

const ObjectID = require('mongodb').ObjectID;

var bookId = new ObjectID(req.params.id),
    subId = new ObjectID(req.params.subid);

Book.findOneAndUpdate(
  { _id: bookId, chapters: { $elemMatch: { _id: subId } } },
  { $set: { chapters: { title: 'new title' } } }, { 'new': true }).exec();
});

score 1 · Accepted Answer · answered May 11 '18 at 19:49

1

think you need to use positional operator $ info

Book.findOneAndUpdate(
    { _id: req.params.id, 'chapters._id': req.params.subid },
    { $set: 'chapters.$': { 'title': 'new title' } }).exec();

OR to update only title

Book.findOneAndUpdate(
    { _id: req.params.id, 'chapters._id': req.params.subid },
    { $set: 'chapters.$.title': 'new title'}).exec();

answered May 11 '18 at 19:49

Andrey Tyndyk

60
3

it should be `Book.findOneAndUpdate( { _id: req.params.id, 'chapters._id': req.params.subid }, { $set: {'chapters.$': { 'title': 'new title' } }}).exec();` – Xiaoyu Xu Mar 17 '20 at 11:24

findOneAndUpdate: using parent and subdocument id to update

2 Answers2