如何部分更新 MongoDB 中的数组和对象，以便将新值添加到数组中

Question

给定以下架构

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

var favoriteSchema = new Schema({
dishes: [{
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Dish'
}],
postedBy: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User'
}
}, {
 timestamps: true
});

var Favorites = mongoose.model('Favorite', favoriteSchema);
module.exports = Favorites;

和下面的路由器

var bodyParser = require('body-parser');
var express = require('express');
var mongoose = require('mongoose');

var Favorites = require('../models/favorites');
var Verify = require('./verify');

var favoritesRouter = express.Router();

favoritesRouter.use(bodyParser.json());
favoritesRouter.route('/')
.post(Verify.verifyOrdinaryUser, function(req,res,next){
    req.body.postedBy = req.decoded._doc._id;
    console.log('nana ' + req.body.postedBy);
    Favorites.create(req.body,function(err,fav){
        if(err) throw err;

        fav.dishes.push(req.body);
        fav.save(function(err,fa){
            if(err) throw err;
            res.json(fa);
        })
    });
});
module.exports = favoritesRouter;

每次我执行邮递员的要求时，我都会将菜肴 ID 附加到请求的正文中。

 {
   "_id": "577a996155d73cf02b0d516f"
 }

我想不出将这个 ID 插入到数组中的解决方案，而不是重新创建整个对象，数组中只有 1 个 id。我是在做错什么，还是必须做其他事情才能执行我想要的逻辑？

Answer 1

您将要查询数据库以查找先前保存的对象，附加到数组，标记为已修改，然后保存。它看起来像这样：

var bodyParser = require('body-parser');
var express = require('express');
var mongoose = require('mongoose');

var Favorites = require('../models/favorites');
var Verify = require('./verify');

var favoritesRouter = express.Router();

favoritesRouter.use(bodyParser.json());
favoritesRouter.route('/')
.post(Verify.verifyOrdinaryUser, function(req,res,next){
    req.body.postedBy = req.decoded._doc._id;
    console.log('nana ' + req.body.postedBy);
    Favorites.findById(someID, function(err, fav){
        if(err) throw err;

        fav.dishes.push(req.body);
        fav.markModified('dishes')
        fav.save(function(err,fa){
            if(err) throw err;
            res.json(fa);
        })
    });
});

您需要弄清楚如何在其中获取 ID。您可以使用动态端点：​​

favoritesRouter.use(bodyParser.json());
favoritesRouter.route('/:id')
.post(Verify.verifyOrdinaryUser, function(req,res,next){
    var someID = req.params.id
})

或者您可以搜索发布者（.find({postedBy: req.decoded._doc._id},... 而不是 .findById(someID,...）或其他内容