javascript - Mongoose update subdocument of subdocument -

my schema definition below. userschema has embedded cards in turn has many transactions..

var transactionschema = new schema({   merchantname: string,   transactiontime: date,   latitude: number,   longitude: number,   amount: number });  var cardschema = new schema({   cardissuer: string,   lastfour: string,   expirationdate: string,   transactions : [transactionschema] });  /*  * ...user schema...   */ var userschema = new schema({   name: string,   email: { type: string, lowercase: true },   role: {     type: string,     default: 'user'   },   hashedpassword: string,   provider: string,   salt: string,   imageurl: string,   phonenumber: string,   card: [cardschema] }); 

i want add transaction card in userschema not sure how in mongoose / mongodb

i identify user , card follows..

the api call goes through auth middleware first

function isauthenticated() {   return compose()     // validate jwt     .use(function(req, res, next) {       // allow access_token passed through query parameter       if(req.query && req.query.hasownproperty('access_token')) {         req.headers.authorization = 'bearer ' + req.query.access_token;       }       validatejwt(req, res, next);     })     // attach user request     .use(function(req, res, next) {       user.findbyid(req.user._id, function (err, user) {         if (err) return next(err);         if (!user) return res.send(401);          req.user = user;         next();       });     }); }   // update based on neil's answer below... exports.create = function(req, res) {   //var useritem = req.user;   //console.log(useritem._id);   //console.log(req.params.card);   transaction.create(req.body, function(err, transaction){      console.log(transaction);           //id = mongoose.types.objectid;            user.findoneandupdate({"card._id":id(req.params.card)},{              // $set : {             //   role: 'user1'             // } ---- update operation works!!               "$push": {                   "card.$.transactions": transaction               } // -- update operation causes error ...           }, function(err,user) {             // updated document here             console.log('err' + err + " user " + user) ;             return res.json(200, user);         }       )     // }    // }) }) }; 

adding new elements inner array not difficult, need match position of outer array update in query , apply positional $ operator in update portion.

var transaction; // , initialize new transaction  user.findoneandupdate(     { "card._id": cardid },     {          "$push": {             "card.$.transactions": transaction.toobject()         }     },     function(err,user) {         // updated document here     } ) 

so straightforward $push operations. careful ever want $push or $pull trying update @ position of in "inner" array not possible since positional operator contain first match, or position in "outer" array.