Update embedded object array inside array in MongoDB - mongodb

Question

I have a document like :
{
"_id": "1000",
"answer_count": 0,
"answer_order": 0,
"fields": [{
"name": "client_name",
"id": "com28",
"title": "Client",
"required": true,
"instruct": "",
"dateType": "text"
}, {
"name": "id_radio",
"id": "com26",
"title": "hobby",
"required": false,
"instruct": "",
"value": [{
"name": "Please select",
"selected": true,
"lid": "-1",
"defaultTip": true
}, {
"name": "option1",
"selected": false,
"lid": "0"
}, {
"name": "option2",
"selected": false,
"lid": "1"
}, {
"name": "option3",
"selected": false,
"lid": "2"
}]
}]
}
I try:
db.survey_stat.update({
"fields.id" : "com26",
"fields.value.name":"option1"
},
{
"$inc":{
"fields.0.value.$.selected_count":1
}
})
But it doesn't update any field. How can I incr the specific field inside a array ?

Answer 1

The array-entry with fields.id: "com26" which you want to change is fields.1 not fields.0. This means you are trying to change the wrong entry of the fields array.
Unfortunately the $-placeholder can only be used once in a field-path. When you have two nested arrays, it won't work. There is an open bugtracker ticket about this issue. The only workaround is to retrieve and replace the whole array-entry in which the nested field occurs.