mongodb

问题 How do I target an subdocument in the authors array as shown below, in order to update it? collection.update({'_id': "4f44af6a024342300e000001"}, {$set: { 'authors.?' }} ) The document: { _id: "4f44af6a024342300e000001", title: "A book", created: "2012-02-22T14:12:51.305Z" authors: [{"_id":"4f44af6a024342300e000002"}] } 回答1: By specifying actual position of embedded document like this: // update _id field of first author collection.update({'_id': "4f44af6a024342300e000001"}, {$set: { 'authors

问题 How do I target an subdocument in the authors array as shown below, in order to update it? collection.update({'_id': "4f44af6a024342300e000001"}, {$set: { 'authors.?' }} ) The document: { _id: "4f44af6a024342300e000001", title: "A book", created: "2012-02-22T14:12:51.305Z" authors: [{"_id":"4f44af6a024342300e000002"}] } 回答1: By specifying actual position of embedded document like this: // update _id field of first author collection.update({'_id': "4f44af6a024342300e000001"}, {$set: { 'authors

问题 I'm new express, nodejs, mongodb. I'm building a website for a clothing shop. They want to upload images frequently, maybe every 2 days they will upload new images, and those images need to be shown on the website quickly, thumbnails. Click on the image will show detail the product, etc. My question is what are the best ways to store images? Store images into hard disk and just store the absolute path into database mongodb? Stored images as binary/base64 into database mongodb? How to load

问题 I'm new express, nodejs, mongodb. I'm building a website for a clothing shop. They want to upload images frequently, maybe every 2 days they will upload new images, and those images need to be shown on the website quickly, thumbnails. Click on the image will show detail the product, etc. My question is what are the best ways to store images? Store images into hard disk and just store the absolute path into database mongodb? Stored images as binary/base64 into database mongodb? How to load

问题 I'm new express, nodejs, mongodb. I'm building a website for a clothing shop. They want to upload images frequently, maybe every 2 days they will upload new images, and those images need to be shown on the website quickly, thumbnails. Click on the image will show detail the product, etc. My question is what are the best ways to store images? Store images into hard disk and just store the absolute path into database mongodb? Stored images as binary/base64 into database mongodb? How to load

问题 In express and mongodb I want delete document by id findOneAndDelete() Can not delete by _id, can only delete by field ! why ? db.collection('quotes').findOneAndDelete({name: req.body.name}, (err, result) => { if (err) return res.send(500, err) }) var ObjectId = require('mongodb').ObjectId; var collection = db.collection('quotes'); collection.remove({_id: new ObjectId(req.body.id)}, function(err, result) { if (err) { console.log(err); } else { res.send('A darth vadar quote got deleted') } });

问题 In express and mongodb I want delete document by id findOneAndDelete() Can not delete by _id, can only delete by field ! why ? db.collection('quotes').findOneAndDelete({name: req.body.name}, (err, result) => { if (err) return res.send(500, err) }) var ObjectId = require('mongodb').ObjectId; var collection = db.collection('quotes'); collection.remove({_id: new ObjectId(req.body.id)}, function(err, result) { if (err) { console.log(err); } else { res.send('A darth vadar quote got deleted') } });

问题 So i'm new with mongodb and mapreduce in general and came across this "quirk" (or atleast in my mind a quirk) Say I have objects in my collection like so: {'key':5, 'value':5} {'key':5, 'value':4} {'key':5, 'value':1} {'key':4, 'value':6} {'key':4, 'value':4} {'key':3, 'value':0} My map function simply emits the key and the value My reduce function simply adds the values AND before returning them adds 1 (I did this to check to see if the reduce function is even called) My results follow: {'

问题 So i'm new with mongodb and mapreduce in general and came across this "quirk" (or atleast in my mind a quirk) Say I have objects in my collection like so: {'key':5, 'value':5} {'key':5, 'value':4} {'key':5, 'value':1} {'key':4, 'value':6} {'key':4, 'value':4} {'key':3, 'value':0} My map function simply emits the key and the value My reduce function simply adds the values AND before returning them adds 1 (I did this to check to see if the reduce function is even called) My results follow: {'

问题 So i'm new with mongodb and mapreduce in general and came across this "quirk" (or atleast in my mind a quirk) Say I have objects in my collection like so: {'key':5, 'value':5} {'key':5, 'value':4} {'key':5, 'value':1} {'key':4, 'value':6} {'key':4, 'value':4} {'key':3, 'value':0} My map function simply emits the key and the value My reduce function simply adds the values AND before returning them adds 1 (I did this to check to see if the reduce function is even called) My results follow: {'