Proper way to use .populate() mongodb Node.js

Question

I am trying to attach the full user model to each comment in my comments section. Since mongodb doesn't have joins I have been trying to figure out how to use .populate() to add the user object from the controller. As I understand it, to use the populate function there are only two things you must do.

Define a ref in the model.
Call .populate() on the name of the field which has a ref defined.

I have defined the ref in the model to the 'User' model:

var commentSchema = new mongoose.Schema({
  author: { type: String, ref: 'User' },
  description: String,
  commentID: String,
  hasParent: String,
  parentComment: String,
  timestamp: { type: Number, default: 0 },
});

Then I am trying to add the user model to the author field in the comment object:

Comment
  .find() 
  .populate('author')
  .exec(function (err, comments) {
    console.log(comments);
  });

Is there a step that I am missing? I was hoping to see all the comments with the full user object in the author field of each comment.

Your populate() does not seem to be the problem. I don't knwo about the structure of your User model, but you should reference the _id of the User. author: {type: Schema.ObjectId, ref:'User'} — super-qua
– super-qua, Commented Nov 12, 2014 at 8:18

Youngin · Accepted Answer · 2014-11-12 16:34:52Z

2

The solution was deleting the comments collection from mongodb. Starting fresh it works as expected. If anyone runs into a similar problem try deleting the collection of objects that were created before you had added a ref to the model.

answered Nov 12, 2014 at 16:34

Youngin

2615 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dharman · Accepted Answer · 2020-04-12 12:57:24Z

0

Please consider making following changes.

author: { type: String, ref: 'User' };
authot: { type: Schema.Types.ObjectId, ref:'User'};

edited Apr 12, 2020 at 12:57

Dharman♦

33.9k27 gold badges106 silver badges157 bronze badges

answered Apr 11, 2020 at 15:06

Chirag Munjal

162 bronze badges

1 Comment

Jason Aller Over a year ago

Did you mean authot? Code only answers can almost always be improved by adding some explanation of how and why they work.

Collectives™ on Stack Overflow

Proper way to use .populate() mongodb Node.js

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related