Mongodb $addToSet an object into nested array

Question

I have tried to insert an object into an array inside another array which it only insert an empty object.

db.players.update({ username: crUserName }, { $addToSet: { finditem: nitem[0] } },{upsert:true} , function (err, doc)

nitem[0] is an object.

however, the result I found from the database is like this

I have tried to insert value into this array , it worked but not with object. I have done some research but I found nothing.

I hope someone here can help me! thanks.

===Updated=== Nitem[0] contain information of the item i want to put into the array "finditem". It looks like this

There is not err return for this, everytime I update, it says {ok:1, nModified:1, n:1}

Is there is anything in err object ? Print it add . Also add what nitem[0] contains . Add what they have in question . — Himanshu sharma
– Himanshu sharma, Commented Jan 4, 2018 at 5:55

shivshankar · Accepted Answer · 2018-01-04 06:00:04Z

1

$addToSet doesn't compair whole object. this is not mongo feature currently. It's a little tricky. you can do it like somting

Player.findOneAndUpdate({
        username: crUserName,
        "finditem._id" : {$ne : nitem[0]._id }
    },
    {
        // addToSet insert if nitem _id not exists .
        $addToSet: {
            finditem: nitem[0]
        }
    },
    {
        upsert: false,
        new: true
    },(err, results)=>{
        console.log(err, results);
})

answered Jan 4, 2018 at 6:00

shivshankar

2,1351 gold badge20 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Johnathan Li Over a year ago

i am using Mongojs, so i assuming it will be findAndModify?

Johnathan Li Over a year ago

I tried, the result it return as What i need! However, When I query all players info. It still showing empty object under finditem array as I have put the picture above. Do you know any reason why?

shivshankar Over a year ago

make sure while test in mongo shell use .... {$ne : ObjectId(nitem[0]._id) } and test with a new record so debug can easy

Johnathan Li Over a year ago

I found the problem which related to another issue. thanks for the answer.

Collectives™ on Stack Overflow

Mongodb $addToSet an object into nested array

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related