node.js - Can I populate ref's in a mongoose.js model instead of everytime I query? -

intro: creating stackexchange clone using node , mongo learn language. working on api.

i have following 'questionschema':

var questionschema = new schema({   _id       : {type: string, default: shortid.generate},   title     : {type: string, required: true},   question  : {type: string, required: true},   user      : {type: schema.objectid, ref: 'user'},   points    : {type: number, default: 0},   date      : {type: date, default: date.now},   answers   : [answerschema],   votes     : [{                   user: {type: schema.objectid, ref: 'user', required: true},                   vote: {type: number, enum: [-1,0,1]}               }],   __v       : {type: number, select: false} }); 

the idea when user votes on question points field incremented (or decremented) , userid , vote added votes array. have vote array detect if user has voted , prevent additional votes.

the problem: i'm having trouble checking if user has voted (checking if userid exists in votes array). have been playing around adding method 'hasvoted' questionschema but:

1. i'm not sure how make check happen.
2. i'm not sure if there way me filter votes array during query (at mongodb) instead of after node gets results.

this attempt @ method know wrong:

//has user voted on question? questionschema.methods.hasvoted = function (userid, cb) {   this.votes.filter(function(vote) {     if(userid == vote._id) {         return '1';     } else {         return '0';     }   }); }; 

i recommend make vote schema so

var voteschema = new schema({   user: {type: schema.objectid, ref: 'user', required: true},   vote     : {type: number, required: true} }) var questionschema = new schema({   _id       : {type: string, default: shortid.generate},   title     : {type: string, required: true},   question  : {type: string, required: true},   points    : {type: number, default: 0},   date      : {type: date, default: date.now},   answers   : [answerschema],   votes     : [{type: schema.objectid, ref: 'vote', required: false}] }); 

then question , go through votes.

questionschema.findbyid(question.id)      .populate('votes')      .exec(function (err, question) {      // go through votes here  } 

or query if there question user id inside votes

 questionschema.find()      .and([{_id:questionid,},{votes.user:userid}])      .populate('votes') //dunno if have populate think don't have      .exec(function (err, user) {      // check if(user)  } 

or described here findone subdocument in mongoose

//edit or if don't change schema

questionschema.find({votes.user:userid})  .exec(function (err, user) {    // should return questions user id in votes want specific question in , in example above  } 

and if want 1 element array have make projection described here how find document , single subdocument matching given criterias in mongodb collection