MongoDB : adding element to inner json object while both key-value stored in variables

Question

MongoDB : adding element to inner json object while both key-value stored in variables

i am trying to update a document in mongo db with nodejs native driver.

initially it was inserted like:

matches {
    _id:2001,
    requester:"MITH",
    accepter:"NIKK",
    toss:"MITH",
    bat:"NIKK",
    scores:{"MITH":220},
    status:0,
    won:"MITH"
}

now i need to update the document where i need to insert a new element "NIKK":198 to scores object to make it scores:{"MITH":220,"NIKK":198}

problem is the key comes in a variable only. and when i update it is not updating

Below is the code with which i am trying

var _jsonMatch = {status:4};
var _scorepush = {}
_scorepush[variablevalue] = 198; // variablevalue in reference above is NIKK
var data = {"$set": _jsonMatch,"$push": {"scores":_scorepush} }
mith.findAndModify({_id:mith.db.bson_serializer.ObjectID.createFromHexString(matchId)},
        [],
        data,
        { upsert: true,new:true },
        function(error, match){ 
          if( error ) callback(error);
          else callback(null, match);
        });

EDIT :

I tried $addToSet instead of $push and i got the below error in callback with data undefined.

{ [MongoError: Cannot apply $addToSet modifier to non-array] name: 'MongoError', lastErrorObject: { err: 'Cannot apply $addToSet modifier to non-array', code: 12591, n: 0, connectionId: 56, ok: 1 }, errmsg: 'Cannot apply $addToSet modifier to non-array', ok: 0 } undefined

javascript
json
node.js
mongodb
nosql

Answer 1

You need to build up your $set object programmatically to use dot notation in the key that sets 'scores.NIKK'. So to update the doc you've shown above:

variablevalue = 'NIKK';
var set = {
    status: 4
};
set['scores.' + variablevalue] = 198;
mith.findAndModify({_id: 2001},
    [],
    { $set: set },
    { upsert: true, new: true },
    function(error, match){
        if( error ) callback(error);
        else callback(null, match);
    }
);

Note: the awkwardness of this is because you're using dynamic keys that you need to build up at run-time. Consider re-working your schema so that scores is an array that looks something like this instead:

scores: [{name: 'MITH', value: 220}, {name: 'NIKK', value: 198}]

Answer 2

I think you want $set instead of $push:

var _jsonMatch = {status:4};
var _scorepush = {}
_scorepush[variablevalue] = 198; // variablevalue in reference above is NIKK
_jsonMatch["scores"] = _scorepush;
var data = {"$set": _jsonMatch };
mith.findAndModify({_id:mith.db.bson_serializer.ObjectID.createFromHexString(matchId)},
        [],
        data,
        { upsert: true,new:true },
        function(error, article){ 
          if( error ) callback(error);
          else callback(null, article);
        });