Question

Initialization‘ update = {‘$inc’: {“Prodects.$.price”: 1}},’

But cannot be passed inUpdate parameterThe result is‘$inc’: {},

Version number

node v6.6.0
 "mongoose": "^4.7.5",
 MongoDB shell version v3.4.0

app.js

# Turn on debug mode
 var mongoose = require('mongoose').set('debug', true);  ;

router.js

router.get('/test', function(req, res, next){
 
 var conditions = {"Prodects.id": "2"},
 update =  {'$inc': {"Prodects.$.price": 1}},
 options =  {upsert:true};
 
 CartModel.update(conditions, update, options, function(err) {
 });
 });

The terminal shows that the data of the second parameter is empty, butDeclares an object

hotnode  node process restarted
 
 { '$inc': { 'Prodects.$.price': 1 } }
 Mongoose: carts.update({ 'Prodects.id': '2' }, { '$inc': {}, '$setOnInsert': { __v: 0 } }, { upsert: true })

The second parameter-‘$inc’: {}, initialization‘ update = {‘$inc’: {“Prodects.$.price”: 1}},’

So that the data in the database cannot be updated

Answer 1

Summary of Mongoose’s Problems

var conditions = {"Prodects.id": "2"},
 update =  {'$inc': {"Prodects.$.price": 1}},
 options =  {upsert:true};
 
 CartModel.update(conditions, update, options, function(err) {
 });
 });

Print results

{ '$inc': { 'Prodects.$.price': 1 } }
 Mongoose: carts.update({ 'Prodects.id': '2' }, { '$inc': {}, '$setOnInsert': { __v: 0 } }, { upsert: true })

The following methods can be used

Model.collection.update(conditions, update, function(err, result){
 res.send(result)
 });