Bounding Intermediate Model

Question

I am using MongooseDeepPopulate for a project. I have SchemaA, SchemaB, SchemaC, SchemaD. My SchemaD, SchemaC are connected to SchemaB, and SchemaB is connected to SchemaA.

I did like this.

var deepPopulate = require('mongoose-deep-populate')(mongoose);
AlbumSong.plugin(deepPopulate, {
    populate: {
        'song.category': {select: 'name status'},
        'song.poetId': {select: 'name status'}
    }
});

songis a mix with category and poetics. I am successful with marginal fields from categoryand poetId. But I also want to limit the fields from the intermediate model song. My search request is similar to

AlbumSong.find(condition)
    .deepPopulate('song.category song.poetId')
//  .deepPopulate('song.category song.poetId' , '_id category poetId name nameHindi invalid status') // I tried this as well to limit records from song model as well.
    .exec(function(err, playlist) {
        callback(err, playlist);
    });

Where am I mistaken.

Answer 1

If you want to limit the fields to AlbumSong, you can simply use the function provided by mongoose , for example:

AlbumSong.find(condition)
   .select('_id category poetId name nameHindi invalid status')
   .deepPopulate(...)

. :

var userSchema = new Schema({
  name:  String,
  email: String
});

var CommentSchema = new Schema({
  author  : {type: Schema.Types.ObjectId, ref: 'User'},
  title: String,
  body: String
})

var PostSchema = new Schema({
  title:  String,
  author: { type: Schema.Types.ObjectId, ref: 'User' },
  comments: [{type: Schema.Types.ObjectId, ref: 'Comment'}],
  body:   String
});

PostSchema.plugin(deepPopulate, {
  populate: {
    'author': { select: 'name' },
    'comments': { select: 'title author' },
    'comments.author': { select: 'name' },
  }
});

deepPopulate author, comments comments.author. , :

Post.find().select('title author comments').deepPopulate('author comments.author').exec(function(err, data) {
    // process the data
});

:

[{
    "_id": "56b74c9c60b11e201fc8563f",
    "author": {
        "_id": "56b74c9b60b11e201fc8563d",
        "name": "Tester"
    },
    "title": "test",
    "comments": [
        {
            "_id": "56b74c9c60b11e201fc85640",
            "title": "comment1",
            "author": {
                "_id": "56b74c9b60b11e201fc8563e",
                "name": "Poster"
            }
        }
    ]
}]

, title (body ). .