node.js - mongoose supplying upsert=true erroring out -

i using mongoose first time , declared session model below

var mongoose = require('mongoose'); var schema = mongoose.schema;  var sessionschema = new schema({     session_id : string,     users : [{         user_id : string,         user_type : string,     }],     start_time : date });   var sessioninfo = mongoose.model('sessioninfo', sessionschema);  module.exports = sessioninfo 

now trying update users array, whenever user joined socket server same session id users detail should updated

below code that

    newsession.update({session_id : sessionid},     {$push: {users :          {user_id : userid,          user_type : usertype}     }},     {safe: true, upsert: true},        function(err,model){         console.log(err);     }); 

but whenever client connects node js server below error

tue apr 28 2015 01:53:07 gmt+0530 (ist) connection accepted.

/home/rahulshr/node_modules/mongoose/lib/query.js:1878 oldcb(error, result ? result.result : { ok: 0, n: 0, nmodified: 0 }); ^ typeerror: object not function @ query.callback (/home/rahulshr/node_modules/mongoose/lib/query.js:1878:7) @ /home/rahulshr/node_modules/mongoose/node_modules/kareem/index.js:167:19 @ /home/rahulshr/node_modules/mongoose/node_modules/kareem/index.js:103:16 @ process._tickcallback (node.js:415:13)

i found root cause, instead of calling update instance of session schema (newsession in case) should call sessioninfo