How to delete item of array within subdocuments if nested id is found

Question

{
    "_id" : ObjectId("55a4b23636e6ba35079eb497"),
    "userName" : "David",
    "email" : "david@gmail.com",
    "image" : "https://lh5.googleusercontent.com/-ivBeNFeatn4/AAAAAAAAAAI/AAAAAAAABkk/aa86ghW9VRg/photo.jpg?sz=50",
    "trade" : [ 
        {
            "selectedCar" : {
                "model" : "Mikecar",
                "year" : 77878,
                "condition" : "hkjhkj",
                "color" : "hkjhjkhjkhjk",
                "_id" : "55a4b22d36e6ba35079eb496",
                "imageUrl" : "http://cliparts.co/cliparts/Big/Kkz/BigKkzggT.png",
                "userName" : "josh Smith",
                "email" : "josh@gmail.com"
            },
            "myCar" : {
                "model" : "Son90098",
                "year" : 879,
                "condition" : "kjhjkhkhj",
                "color" : "khjhjkhjk",
                "_id" : "55a4b24036e6ba35079eb498",
                "imageUrl" : "http://cliparts.co/cliparts/Big/Kkz/BigKkzggT.png"
            },
            "myEmail" : "david@gmail.com"
        },
    "__v" : 2
}



User.findOneAndUpdate({'trade.myCar._id' : req.body.myCar._id }, {$pull: {'trade.$': {'trade.myCar._id' : req.body.myCar._id }}}, function(err,trade){
})

I want to find the nested id of item in the nested array trade and delete all items where trade.myCar._id = req.body.myCar._id . I want to remove the item which contains the object selectedCar and myCar

Answer 1

Use "new" to return the modified document and the argument to $pull in the "inner" name only:

User.findOneAndUpdate(
   { "trade.myCar._id" : req.body.myCar._id }, 
   { "$pull": {
       "trade.$": { "myCar._id" : req.body.myCar._id }
   }},
   { "new": true },
   function(err,trade) {

   }
})

Note: This does remove the entire array element as you ask. To just remove "myCar" then use $unset :

User.findOneAndUpdate(
   { "trade.myCar._id": req.body.myCar._id }, 
   { "$unset": { "trade.$.myCar": "" }},
   { "new": true },
   function(err,trade) {

   }
})

In that case the array element is intact, but that key is gone from that element.