javascript - Angular - TypeError: path must be a string for $scope.formData? -

i have form has number field:

input type="number" class="form-control" placeholder="0" ng-model="formdata.position" 

and when submit form, .error function responds 500 internal server error, error: typeerror: path must string

$scope.createproduct = function() {          // validate formdata (using our exentions.js .filter) make sure there         //if form empty, nothing happen         if (!isemptyobjectfilter($scope.formdata)) {                  // call create function our service (returns promise object)                 emotions.create($scope.formdata)                          // if successful creation, call our function new emotions                         .success(function(data) {                                 $scope.formdata = {}; // clear form our user ready enter                                 $scope.products = data; // assign our new list of emotions                         })                         .error(function(data) {                                 console.log('error: ' + data);                         });         } }; 

can formdata mix of strings , integers?

here's create line in service:

    create : function(emotiondata) {         return $http.post('/api/emotions', emotiondata);     }, 

i have mongoose schema looks this:

var productschema = mongoose.schema({     title : string,     position: number }); 

the stack trace error looks this:

typeerror: path must string     @ query.where (/users/kk/downloads/awaken/v16/node_modules/mongoose/lib/query.js:593:11)     @ function.where (/users/kk/downloads/awaken/v16/node_modules/mongoose/lib/model.js:1040:18)     @ model.<anonymous> (/users/kk/downloads/awaken/v16/app/models/emotion.js:44:35) ... 

which looks lead line (44?) of emotion.js file:

mongoose.model("product").where({_id: {$ne: doc._id}, position: doc.position}).count( function (err, count) { 

and posting here:

increment field on records in mongo?