Mongoose findbyid() return null

Question

I am trying to find a record in my mongo db by its id

No matter I use findbyid(), findone(id,...), it return null

here is my code. what is the solution?

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/Movie', {useNewUrlParser: true})
.then(() => console.log('Connected to Databse'))
.catch(err => console.err('Could not connect to MongoDB', err));

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

const Schema = new mongoose.Schema({
    name: String,
    author: String,
    tags: [String],
    date: Date, 
    isPublished: Boolean,
    price: Number
});

const Data = mongoose.model('Datas', Schema);

async function updateData(id){
const result = await Data.findById(id);
console.log(result);
}
updateData('5a6900fff467be65019a9001');

Silly question: are you 100% sure the record is there in the DB? — Sid, Sep 03 '18 at 10:18
Yes, I am sure. I have use findone() by the 'name' in my database, it return sth. But not work in '_id' — Kenny, Sep 03 '18 at 10:20
you are passing string whereas findById want objectId. Try with objectid — Prashant Tapase, Sep 03 '18 at 10:25
@Sid is right.. You probably don't have this specific record in your db... Running the exact same code works for me.. Just add `Data.create({}).then(console.log)` and copy the returned id to your updateData function... — Ron537, Sep 03 '18 at 10:51
here is a funny point, The _id which is hard code inside the database, is a String type. I just realise it few second ago.Thus, findbyid always not work. Now Problem solved. Thanks everyone — Kenny, Sep 03 '18 at 10:59
Please read my answer on this thread: https://stackoverflow.com/a/58705908/4687359 Hope find it useful. — A. Nadjar, Nov 05 '19 at 07:19

score 43 · Accepted Answer · answered Feb 18 '19 at 02:04

43

I had the same problem. The _id in my DB collection was a String. After I enabled mongoose debug require('mongoose').set('debug', true), I found out that the mongoose query id as ObjectId("yourId") unless we define _id in the Schema. In order to solve the problem I had to add _id:String in to mongoose schema.

const MyDataSchema = new Schema({
  _id: String,
...
...
}

answered Feb 18 '19 at 02:04

Pramod

706
8
8

1

this actually saves my 2-3 hours :) – armin Aug 12 '20 at 17:44
2

`const MyDataSchema = new Schema({ _id: Schema.Types.ObjectId, ... ... }` – Andrei Bexa Dec 30 '20 at 18:19
1

If we add _id to schema, then if we try to save a new document in mongo, it throws error "document must have an _id before saving". I don't think adding _id to the schema is the right solution for it. – saurabhlahoti Apr 01 '21 at 12:42
Yeahhh man, thank you this happened to me after updating the mongoose version – Efraim Jerszurki Mar 13 '22 at 00:34

score 5 · Answer 2 · edited Apr 27 '20 at 20:54

5

There is a simple solution to this:

Replace

const result = await Data.findById(id);

with

const result = await Data.findById(id).exec();

See Mongoose - What does the exec function do? for an explanation on what exec() does

edited Apr 27 '20 at 20:54

Paul Roub

36,322
27
84
93

answered Apr 27 '20 at 20:51

Sylvestaro

101
2
7

4

This did not work for me – Bowis Jul 12 '22 at 09:23

score 3 · Answer 3 · edited Sep 14 '18 at 04:51

3

Check your mongodb database, if _id is storaged as String, findById(id) can not found id. FindById(id) only finds ObjectId('yourId'). You might import database by using mongoimport and including _id in JSON, it's wrong, delete _id in imported JSON.

edited Sep 14 '18 at 04:51

Prashant Gupta

788
8
26

answered Sep 14 '18 at 03:39

Khánh Thọ Nguyễn

31
2

score 2 · Answer 4 · answered Sep 24 '21 at 14:57

2

After hour of searching i needed to add _id to Schema like this:

  _id: { type: Schema.Types.ObjectId },

answered Sep 24 '21 at 14:57

mradex77

118
2
8

Exactly my issue!! thank you :) I had it as a String but since it is saved as objectId it didn't work. – Lev Buchel Nov 02 '21 at 12:36

score 1 · Answer 5 · answered Apr 01 '21 at 12:51

I was also facing the same issue. Then I referred to this solution Make sure the documents in the collection have _id as an Object rather than a String. If you have imported the database entries using a JSON file, just remove all the _id fields and then import it.

After importing, MongoDB will itself assign the _id values to all the entries.

score 0 · Answer 6 · answered Dec 30 '18 at 21:46

In my case, the imported file used to have the _id column as string, so it was messing the DB and I was no able to filter using that column.

Once I deleted the collection, removed the _id column from data file and re-imported it, the _id filtering started working fine.

score 0 · Answer 7 · answered Sep 30 '22 at 07:01

0

I also had the same problem. It was simply solved by using findOne method instead of findById method of mongoose.

findOne syntax -

findOne({id: id-of-user},function(err,foundUser){
console.log(foundUser);
});

answered Sep 30 '22 at 07:01

Leonardo DiCaprio

1

Mongoose findbyid() return null

7 Answers7

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