CODEWITHSUNDEEP
node.jsmongodbmongoose
Vicky Gonsalves
Vicky Gonsalves

Reputation: 11717

Update Nested query in mongoose

I am struggling from last 2 hours to update my nested collection. Can someone please try to guide me in right direction?

var ChoiceSchema = new Schema ({
  body: {type: String, required: true},
  correct: {type: Boolean, required: true},
  timesDisplayed: {type: Number, default: 0},
  timesSelected: {type: Number, default: 0},
  images: {}
});

var QuestionSchema = new Schema({
  contentId: {type: String, required: true},
  questionBody: {type: String, required: true},
  timesAnswered: {type: Number, default: 0},
  timesCorrect: {type: Number, default: 0},
  timesIncorrect: {type: Number, default: 0},
  timesSkipped: {type: Number, default: 0},
  explanation: {
    contentId: {type: String, required: true},
    body: {type: String, required: true},
    images: {}
  },
  images: {},
  choices: [ChoiceSchema]
});

var ExamSchema = new Schema ({
  subject: {type: String, required: true},
  dateCreated: { type: Date, default: Date.now },
  examNumber: Number,
  section1: {
    part1: {
      timeInMinutes: Number,
      instructions: {type: String, required: true},
      questions: [QuestionSchema]
    },
    part2: {}
  },
  section2: {}
});

I am trying to update the timesAnswered property in QuestionsSchema.

 Exam.findById(req.params.id, function (err, exam) {
    var ids=JSON.parse(req.body.ids);
    if(err) { return handleError(res, err); }
    if(!exam) { return res.send(404); }
    if(ids.length) {
      for(var i=0;i<ids.length;++i){
        Exam.update({'section1.part1.questions.$._id':ids[i]},
            { $set: {
              'section1.part1.questions.$.timesAnswered': 1   // <== and here
            }}, function (err, numAffected) {
              if(err) throw err;
            }
          );
      }
    }
    return res.json(exam);
  });

where ids is an array containing question ids

[ '54db8ee6529b197018822eb4',
  '54db8ee6529b197018822ea7',
  '54db8ee6529b197018822ea0' ]

I references this question but I don't know why its not working out for me. Mongoose nested document update failing?

Upvotes: 1

Views: 741

Answers (3)

Rodrigo Medeiros
Rodrigo Medeiros

Reputation: 7862

Your code has two problems.

First, as @yazarubin pointed out, your update condition has an unnecessary $, so just remove it:

Exam.update({'section1.part1.questions._id':id},

Second, you're running an update task (asynchronous task), inside a standard for (synchronous), so it won't wait the update tasks to be completed. In this case you can use the async.each function:

var async = require('async'); // be sure to install and require the async module

async.each(ids, function (id, callback) {
  Exam.update({'section1.part1.questions._id':id},
    { $set: {
      'section1.part1.questions.$.timesAnswered': 1   // <== and here
    }}, function (err, numAffected) {
      if(err) throw err;
      callback();
    }
  );
}, function (error) {
  if (error) res.send(500);
  res.send(exam); // send the response just when all tasks has finished
});

, or you could use some kind of promises library to accomplish this same task.

Upvotes: 1

Yuri Zarubin
Yuri Zarubin

Reputation: 11677

This query should accomplish what you're trying to do (you didn't need the $ in the find clause):

Exam.update({'section1.part1.questions._id':ids[i]}, { 
  $set: {
    'section1.part1.questions.$.timesAnswered':1 
  }}, function(err, numAffected){

  })

Upvotes: 1

Rico Chen
Rico Chen

Reputation: 2298

Can you try:

Exam.findById(req.params.id, function (err, exam) {
    var ids=JSON.parse(req.body.ids);
    if(err) { return handleError(res, err); }
    if(!exam) { return res.send(404); }
    if(ids.length) {
        for(var i=0;i<ids.length;++i){
            var question=exam.section1.part1.questions.id(ids[i]);
            question.timesAnswered=1;
        }
        exam.save(function(err) {
            if(err) throw err;
        });
    }
    return res.json(exam);
});

Upvotes: 0

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