Mongoose delete array element in document and save

Question

I have an array in my model document. I would like to delete elements in that array based on a key I provide and then update MongoDB. Is this possible?

Here\'s my

Answer 1

Answers above are shown how to remove an array and here is how to pull an object from an array.

Reference: https://docs.mongodb.com/manual/reference/operator/update/pull/

db.survey.update( // select your doc in moongo
    { }, // your query, usually match by _id
    { $pull: { results: { $elemMatch: { score: 8 , item: "B" } } } }, // item(s) to match from array you want to pull/remove
    { multi: true } // set this to true if you want to remove multiple elements.
)

Answer 2

You can also do the update directly in MongoDB without having to load the document and modify it using code. Use the $pull or $pullAll operators to remove the item from the array :

Favorite.updateOne( {cn: req.params.name}, { $pullAll: {uid: [req.params.deleteUid] } } )

(you can also use updateMany for multiple documents)

http://docs.mongodb.org/manual/reference/operator/update/pullAll/

Answer 3

keywords = [1,2,3,4];
doc.array.pull(1) //this remove one item from a array
doc.array.pull(...keywords) // this remove multiple items in a array

if you want to use ... you should call 'use strict'; at the top of your js file; :)

Answer 4

Since favorites is an array, you just need to splice it off and save the document.

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var favorite = new Schema({
    cn: String,
    favorites: Array
});

module.exports = mongoose.model('Favorite', favorite);

exports.deleteFavorite = function (req, res, next) {
    if (req.params.callback !== null) {
        res.contentType = 'application/javascript';
    }
    // Changed to findOne instead of find to get a single document with the favorites.
    Favorite.findOne({cn: req.params.name}, function (error, doc) {
        if (error) {
            res.send(null, 500);
        } else if (doc) {
            var records = {'records': doc};
            // find the delete uid in the favorites array
            var idx = doc.favorites ? doc.favorites.indexOf(req.params.deleteUid) : -1;
            // is it valid?
            if (idx !== -1) {
                // remove it from the array.
                doc.favorites.splice(idx, 1);
                // save the doc
                doc.save(function(error) {
                    if (error) {
                        console.log(error);
                        res.send(null, 500);
                    } else {
                        // send the records
                        res.send(records);
                    }
                });
                // stop here, otherwise 404
                return;
            }
        }
        // send 404 not found
        res.send(null, 404);
    });
};

Answer 5

The checked answer does work but officially in MongooseJS latest, you should use pull.

doc.subdocs.push({ _id: 4815162342 }) // added
doc.subdocs.pull({ _id: 4815162342 }) // removed

https://mongoosejs.com/docs/api.html#mongoosearray_MongooseArray-pull

I was just looking that up too.

See Daniel's answer for the correct answer. Much better.

Answer 6

This is working for me and really very helpful.

SubCategory.update({ _id: { $in:
        arrOfSubCategory.map(function (obj) {
            return mongoose.Types.ObjectId(obj);
        })
    } },
    {
        $pull: {
            coupon: couponId,
        }
    }, { multi: true }, function (err, numberAffected) {
        if(err) {
            return callback({
                error:err
            })
        }
    })
});

I have a model which name is SubCategory and I want to remove Coupon from this category Array. I have an array of categories so I have used arrOfSubCategory. So I fetch each array of object from this array with map function with the help of $in operator.