Finding MongoDB documents by _id failing on the type of ObjectId

Question

I'm struggling to find MongoDB documents by their _id field in my ReactJS project.

My collection has documents that looks like so (for example):

    _id: ObjectId("5f6651112efc19f33b34fc39")
    title: "This is a title"
    status: true

I'm using this (greatly simplified) code in a function to find the documents that match the id passed in:

const id = '5f6651112efc19f33b34fc39';
await mongoCollection.find({_id:ObjectId(id)});

ObjectId is defined like so:

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

Yet even if I hard coded the id variable to be the ObjectId string from the document in my database, it fails with this error:

Uncaught (in promise) Error: invalid ObjectId, ObjectId.id must be either a string or a Buffer, but is [{"type":"Buffer","data":[]}]

Printing out id and ObjectId(id) before the await line results in the following:

How should I be satisfying this warning?

Edit: I'm defining my app/collection like so:

const app = new Realm.App({ id: "<app-id>", timeout: 10000 });
const mongo = app.services.mongodb('mongodb-atlas');
const mongoCol = mongo.db('<databaseName>').collection('<collectionName>');

@matrixersp Strangely enough that doesn't work either. I get the same error in my original post. I'm able to use ```find()``` on any other field in my collection just fine. :( — codedude, Sep 20 '20 at 14:39
@RisingSun yep. Exactly like the accepted answer in the first comment of this chain. — codedude, Sep 25 '20 at 20:36
try passing `ObjectId(id)` straight to `find()`. also, check out `findOne` and `findByID` methods — RisingSun, Sep 25 '20 at 20:56
Passing ObjecrtId(id) directly and findOne produce the same errors. I believe findByID is part of mongoose, which I'm not (yet) using in this project...maybe it's worth using it though. — codedude, Sep 25 '20 at 21:23
So maybe it's a bug. Have you tried using BSON's ObjectId instead? Same error? — padaleiana, Sep 26 '20 at 00:12

score 3 · Accepted Answer · answered Sep 26 '20 at 03:53

3

Seems like a known BUG, try to use bson like:

const bson = require('bson');

const id = '5f6651112efc19f33b34fc39';
const bsonObjectId = new bson.ObjectId(id);
await mongoCollection.find({_id: bsonObjectId });

answered Sep 26 '20 at 03:53

Dipen Shah

25,562
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Holy heck this worked! Much appreciated for finding this! – codedude Sep 26 '20 at 20:27

score -2 · Answer 2 · answered Sep 19 '20 at 19:26

-2

Try just _id instead of "_id"

const id = "5f6651112efc19f33b34fc39"
await mongoCollection.find({_id:ObjectId(id)});

Like this!

answered Sep 19 '20 at 19:26

klee214

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Finding MongoDB documents by _id failing on the type of ObjectId

2 Answers2