JSON not fetching success on codeigniter - [object Object] - php

Question

What i'm trying to do here to populate second select from based from the first one with json format.
Everything goes okay i'm getting the results i need with exact num of rows from the model based on the ID which i send with the request but i have this error :
I'm trying to get the mark id based on the model selected which i have in database :
ID MARK_ID VALUE_MARK
Here is my jquery function :
$(document).ready(function(){
$("#mark").change(function() {
var markId= $("#mark").val();
if (markId!= "") {
$.get(
'upload/car_models?mark_id=' + markId,
function(data){
$.each(data, function(key, value){
$("#model").append("<option value='" + key + "'>" + value + "</option>");
})
},
"json"
);
}
});
})
And in my controller i'm doing json encode like this for the variable which is back from the model
echo json_encode($models);
How can i fix this problem with object Object.
Thanks. Any help will be appreciate.
EDIT :
Json structure :
[{"id":"50","mark_id":"50","value_mark":"Refine","value":"JAC"}, {"id":"50","mark_id":"50","value_mark":"Rein","value":"JAC"}]
Here is my json structure. id mark_id value_mark here have 2 rows returned from the model

Answer 1

Your data is an array of objects. WHen you loop over that array with $.each key will be index, and value will be object at that index.
Try:
$.each(data, function(i, obj){
$("#model").append("<option value='" + obj.value + "'>" + obj.value_mark + "</option>");
});
I guessed at what properties you want to assign to <option> value and text

Answer 2

Try this,
$(document).ready(function(){
$("#mark").change(function() {
var markId= $("#mark").val();
if (markId!= "") {
$.get(
'upload/car_models?mark_id=' + markId,
function(data){
var model=$("#model");
model.empty();
$.each(data, function(key, val){
model.append("<option value='" + val.value + "'>" + val.value_mark + "</option>");
});
},
"json"
);
}
});
})