MongoDB用Mongoose得到的对象不能增加属性完美解决方法(两种)

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var productSchema = new Schema({
  "productId":String,
  "producName": String,
  "salePrice":Number,
  "productImage":String
});
module.exports=mongoose.model("Good",productSchema,'goods');

var mongoose = require('mongoose');
var userSchema = new mongoose.Schema({
  "userId": String,
  "userName": String,
  "userPwd": String,
  "orderList": Array,
  "cartList": [
    {
      "productId":String,
      "producName": String,
      "salePrice":Number,
      "productName": String,
      "productImage": String,
      "checked": String,
      "productNum": String
    }
  ],
  "addressList": Array
});
module.exports = mongoose.model("User", userSchema, 'users')
/*commonjs规范*/

Goods.findOne({
            productId: productId
          }, function (err1, doc) {
            
            if (err1) {
              return res.json({
                status: "1",
                msg: err1.message
              })
            } else {
              if (doc) {//商品

                 doc.productNum="1",
                  doc.checked="1",

                userDoc.cartList.push(doc);
                userDoc.save(function (err2) {
                  if (err2) {
                    return res.json({
                      status: "1",
                      msg: err2.message
                    })
                  } else {
                    return res.json({
                      status: "0",
                      msg: '',
                      result: "suc"
                    })
                  }
                })
              }
            }
          })

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var productSchema = new Schema({
  "productId":String,
  "producName": String,
  "salePrice":Number,
  "productImage":String
  "checked": String,
  "productNum": String
});
module.exports=mongoose.model("Good",productSchema,'goods');

 Goods.findOne({productId: productId}, function (err1, doc) {
            var newobj = null;//新对象
            if (err1) {
              return res.json({
                status: "1",
                msg: err1.message
              })
            } else {
              if (doc) {//商品
                newobj = {//新创建一个对象，实现转换mongoose不能直接增加属性的坑
                  productNum: "1",
                  checked: "1",
                  productId: doc.productId,
                  producName: doc.producName,
                  salePrice: doc.salePrice,
                  productName: doc.productName,
                  productImage: doc.productImage,
                }
                userDoc.cartList.push(newobj);
                userDoc.save(function (err2) {
                  if (err2) {
                    return res.json({
                      status: "1",
                      msg: err2.message
                    })
                  } else {
                    return res.json({
                      status: "0",
                      msg: '',
                      result: "suc"
                    })
                  }
                })
              }
            }
          })