Adding to an array in MongoDB using $addToSet

Question

I'm trying to add data to an array defined in my mongoDB called "signedUp" it is within my Timetable Schema. So far i've been able to update other fields of my schema correctly however my signedUp array always remains empty. I ensured the variable being added was not empty.

Here is my Schema

var TimetableSchema = new mongoose.Schema({

date: {
    type: String,
    required: true,
    trim: true
  },
  spaces: {
    type: Number,        
    required: true
  },
  classes: [ClassSchema],
  signedUp: [{
    type: String
  }]


});

This was my latest attempt but no value is ever added to the signedUp array. My API update request

id = {_id: req.params.id};
space = {spaces: newRemainingCapacity};
signedUp = {$addToSet:{signedUp: currentUser}};
Timetable.update(id,space,signedUp,function(err, timetable){
    if(err) throw err;
    console.log("updates");
    res.send({timetable});
});

Thanks

Both space and signedUp should be passed as a second parameter. Are you trying to update spaces or replace entire document ? — mickl
– mickl, Commented Dec 30, 2019 at 19:09
@mickl At the moment i have a spaces counter which updates and i want the array signedup to update, so does that mean i need to split them up into two updates? — Ross
– Ross, Commented Dec 30, 2019 at 19:13

mickl · Accepted Answer · 2019-12-30 19:22:25Z

2

You can take a look at db.collection.update() documentation. Second parameter takes update and 3rd one represents operation options while you're trying to pass your $addToSet as third param. Your operation should look like below:

id = {_id: req.params.id};
space = { $set: { spaces: newRemainingCapacity }};
signedUp = { $addToSet:{ signedUp: currentUser}};
update = { ...space, ...signedUp }

Timetable.update(id,update,function(err, timetable){
    if(err) throw err;
    console.log("updates");
    res.send({timetable});
});

answered Dec 30, 2019 at 19:22

mickl

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Comments

f-person · Accepted Answer · 2019-12-30 19:40:16Z

1

space and signedUp are together the second argument.
try this:

id = {_id: req.params.id};
space = {spaces: newRemainingCapacity};
signedUp = {$addToSet:{signedUp: currentUser}};
Timetable.update(id, {...space, ...signedUp}, function(err, timetable){
    if(err) throw err;
    console.log("updates");
    res.send({timetable});
});

edited Dec 30, 2019 at 19:40

answered Dec 30, 2019 at 19:20

f-person

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1 Comment

mickl Over a year ago

Try to console.log {space, signedUp}

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