How can I rewrite my mongoose query after splitting data from one model into two?

Question

My application stores comments. Previously, my model for this looked like this:

var CommentsSchema = new Schema({
    username: {type: String},
    display_name: {type: String},
    facebook_username: {type: String},
    text_content: {type: String},
    photo_content_url: {type: String},
    hashtags: {type: [String]},
    device_id: {type: String},
    comment_date: {type: Date, default: Date.now},
    friends_only: {type: Boolean, default: false}
}

In each comment, in addition to preserving its details, there were also detailed information about the author, for example. username, facebook_username, device_idFrom which the comment was added, and display_name. There was also a bool flag friends_only, based on which I decided whether this comment should be visible only to users of facebook friends or for everyone.

Building a request node.js/ mongooseto get all comments is as follows:

commentsRoutes.post('/friends', function (req, res) {
    var friends = req.body.friends;
    var publicComments = req.body.publicComments;

    var hashtagsInput = req.body.hashtags;

    var startDate = req.body.startDate;
    var endDate = req.body.endDate;

    var query= {};
    query.$and = [];

    // and condition on start date
    if(startDate != undefined) {
        var startDate = new Date(req.param('startDate'));
        var endDate = new Date(req.param('endDate'));
        query.$and.push({"comment_date":{$gte: startDate}});
        query.$and.push({"comment_date":{$lte: endDate}});
    }

    // and condition on hastags
    if (hashtagsInput != undefined) {
        var hashtags = hashtagsInput.split(",");
        query.$and.push({"hashtags":{$in: hashtags}});
    }

    // creating a OR condition for facebook friends and public flag
    var friend_query = {};
    friend_query.$or = [];

    if (friends != undefined) {
        var friendsSplit = friends.split(",");
        friend_query.$or.push({"facebook_username":{$in: friendsSplit}});
    }

    if (publicComments != undefined && publicComments === "true") {
        friend_query.$or.push({friends_only: false});
    }

    //Merging facebook friend condition with other condition with AND operator.
    query.$and.push(friend_query);

    var finalQuery = Comment.find(query)

, ( , ) ( ).

. :

var CommentsSchema = new Schema({
    user_id: {type: String, required: true, ref: 'users' },
    text_content: {type: String},
    photo_content_url: {type: String},
    hashtags: {type: [String]},
    comment_date: {type: Date, default: Date.now},
    friends_only: {type: Boolean, default: false},
    device_id: {type: String}
}

var UsersSchema = new Schema({
    username: {type: String},
    facebook_username: {type: String},
    display_name: {type: String}
}

, , , . async, mongoose .populate. , , or match populate:

...
var finalQuery = Comment.find(query)

finalQuery.populate({path: 'user_id', 
    select: 'facebook_username display_name username',
    match: {

}});

, . ?

Answer 1

-, , , , , .

, . .

var mongoose = require('mongoose')
  , Schema = mongoose.Schema

var personSchema = Schema({
  _id     : Number,
  name    : String,
  age     : Number,
  stories : [{ type: Schema.Types.ObjectId, ref: 'Story' }]
});

var storySchema = Schema({
  _creator : { type: Number, ref: 'Person' },
  title    : String,
  fans     : [{ type: Number, ref: 'Person' }]
});

var Story  = mongoose.model('Story', storySchema);
var Person = mongoose.model('Person', personSchema);

Story
.findOne({ title: 'Once upon a timex.' })
.populate('_creator')
.exec(function (err, story) {
  if (err) return handleError(err);
  console.log('The creator is %s', story._creator.name);
  // prints "The creator is Aaron"
});

doc: http://mongoosejs.com/docs/populate.html