Mongoose删除文件中的数组元素并保存

Question

我的模型文档中有一个数组.我想根据我提供的密钥删除该数组中的元素,然后更新MongoDB.这可能吗？

这是我的尝试:

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

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

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

exports.deleteFavorite = function (req, res, next) {
    if (req.params.callback !== null) {
        res.contentType = 'application/javascript';
    }
    Favorite.find({cn: req.params.name}, function (error, docs) {
        var records = {'records': docs};
        if (error) {
            process.stderr.write(error);
        }
        docs[0]._doc.favorites.remove({uid: req.params.deleteUid});

        Favorite.save(function (error, docs) {
            var records = {'records': docs};
            if (error) {
                process.stderr.write(error);
            }
            res.send(records);

            return next();
        });
    });
};

到目前为止,它找到了文档,但删除或保存工作.

Answer 1

您也可以直接在MongoDB中进行更新,而无需加载文档并使用代码对其进行修改.使用$pull或$pullAll运算符从数组中删除项:

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

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

Answer 2

已检查的答案确实有效,但最近在MongooseJS中正式使用,你应该使用pull.

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

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

我也只是看着那个.

请参阅Daniel的答案以获得正确的答案.好多了.

Answer 3

由于收藏夹是一个数组,您只需要将其拼接出来并保存文档.

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 4

上面的答案显示了如何删除数组，以及如何从数组中拉出对象。

参考：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.
)