Mongoose - using Populate on an array of ObjectId

Question

I've got a schema that looks a bit like:

var conversationSchema = new Schema({
    created: { type: Date, default: Date.now },
    updated: { type: Date, default: Date.now },
    recipients: { type: [Schema.ObjectId], ref: 'User' },
    messages: [ conversationMessageSchema ]
});

So my recipients collection, is a collection of object id's referencing my user schema / collection.

I need to populate these on query, so i'm trying this:

Conversation.findOne({ _id: myConversationId})
.populate('user')
.run(function(err, conversation){
    //do stuff
});

But obviously 'user' isn't populating...

Is there a way I can do this?

score 119 · Answer 1 · edited Mar 16 '13 at 13:59

119

For anyone else coming across this question.. the OP's code has an error in the schema definition.. it should be:

var conversationSchema = new Schema({
    created: { type: Date, default: Date.now },
    updated: { type: Date, default: Date.now },
    recipients: [{ type: Schema.ObjectId, ref: 'User' }],
    messages: [ conversationMessageSchema ]
});
mongoose.model('Conversation', conversationSchema);

edited Mar 16 '13 at 13:59

jackdbernier

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answered Nov 06 '12 at 03:20

Duncan_m

2,477
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5

You sir just saved me a world of pain. *tips hat* – Khalid Bajwa Jul 27 '14 at 02:56
1

Good way ! but how can you do an array of unique object id? With no duplicate? – Gura Mar 31 '15 at 12:27
4

{ type: Schema.ObjectId, ref: 'User' , unique: true } – Muli Yulzary Dec 28 '15 at 14:43
@MuliYulzary, I don't think that's right based on the docs right [here](https://mongoosejs.com/docs/validation.html#the-unique-option-is-not-a-validator). They claim it's `not` a validator but only helps in the creation of `MongoDB` indexes. – Dev Yego Nov 10 '20 at 05:31
1

not working. returning empty array. my mongoose v5.11.14 – Sushil Feb 01 '21 at 11:13

aaronheckmann · Accepted Answer · 2013-08-13T21:37:39.853

39

Use the name of the schema path instead of the collection name:

Conversation.findOne({ _id: myConversationId})
.populate('recipients') // <==
.exec(function(err, conversation){
    //do stuff
});

edited Aug 13 '13 at 21:37

answered May 14 '12 at 21:33

aaronheckmann

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my mongoose v5.11.14 – Sushil Feb 01 '21 at 11:12

Mongoose - using Populate on an array of ObjectId

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