Return certain fields with .populate() from Mongoose

Question

I\'m getting returned a JSON value from MongoDB after I run my query. The problem is I do not want to return all the JSON associated with my return, I tried searching the docs a

Answer 1

I'm not completely clear on what you mean by "returning a field", but you can use a lean() query so that you can freely modify the output, then populate both fields and post-process the result to only keep the field you want:

.lean().populate('user', 'email.address facebook.address')
  .exec(function (err, subscription){ 
    if (subscription.user.email.address) {
        delete subscription.user.facebook;
    } else {
        delete subscription.user.email;
    }
  });

Answer 2

If you only want a few specific fields to be returned for the populated documents, you can accomplish this by passing the field name syntax as the second argument to the populate method.

Model
.findOne({ _id: 'bogus' })
.populate('the_field_to_populate', 'name') // only return the Persons name
...

See Mongoose populate field selection

Answer 3

Try to do this:

applicantListToExport: function (query, callback) {
  this
   .find(query).select({'advtId': 0})
   .populate({
      path: 'influId',
      model: 'influencer',
      select: { '_id': 1,'user':1},
      populate: {
        path: 'userid',
        model: 'User'
      }
   })
 .populate('campaignId',{'campaignTitle':1})
 .exec(callback);
}

Answer 4

In the following query i retrieved articles which match the condition show=true the retrieved data title and createdAt also retrieve the category of article only the title of category and it's id.

let articles = await articleModel
        .find({ show: true }, { title: 1, createdAt: 1 })
        .populate("category", { title: 1, _id: 1 });

Answer 5

Just to complement the answers above, if you want to include everything but only exclude certain attributes, you can do the following:

.populate('users', {password: 0, preferences: 0})

Answer 6

you to try :

Post.find({_id: {$nin: [info._id]}, tags: {$in: info.tags}}).sort({_id:-1})
.populate('uid','nm')
.populate('tags','nm')
.limit(20).exec();