如何删除猫鼬中的嵌入式方案文件? [英] How to remove embedded scheme document in mongoose?

问题描述

类似删除存在问题 我的架构

Having a problem with like removal My schema

/**
* Article Schema
 */
var Comments = new Schema({
    body: { type : String, default : '' },
    user: { type : Schema.ObjectId, ref : 'User' },
    createdAt: { type : Date, default : Date.now }
})
var Likes = new Schema({
    user: { type : Schema.ObjectId, ref : 'User' },
    createdAt: { type : Date, default : Date.now }
  })

var ArticleSchema = new Schema({
  title: {type : String, default : '', trim : true},
  body: {type : String, default : '', trim : true},
  geo: {type: [Number], set: setTags},
  user: {type : Schema.ObjectId, ref : 'User'},
  comments: [Comments],
  likes: [Likes],
  tags: {type: [], get: getTags, set: setTags},
  image: {type:String, default : ''},
  createdAt  : {type : Date, default : Date.now}
})

我想提供类似/不一样的功能，添加类似的作品，但删除只是不会更改文档. 控制器:

And I want to make like/unlike functionality, adding like works but removing simply doesnt change the document. Controller:

exports.like = function (req, res) {
var article = req.article
var user = req.user
Article.getArticleByWithLikesByUserId(req.user.id, function(err, articles) {
    console.log(articles);
    if(!articles.length){

      console.log('adding like',new Date);
      article.addLike(user, function (err) {
        if (err) return res.render('500')
        res.redirect('/articles/'+ article.id)
      });
    }
    else{
        console.log('removing like',new Date);
        article.removeLike(user, function (err) {
            if (err) return res.render('500')
            res.redirect('/articles/'+ article.id)
        });

    }

});

模式方法:

addLike: function (user, cb){

this.likes.push({
  user: user._id
})

this.save(cb);
},

removeLike: function (user, cb){
    var that = this;
    this.likes.forEach(function(like, index) { 
      if(like.user == user.id){
         var newLikesObj = that.likes.toObject(); 
         console.log("before splice:\n ",newLikesObj);
         newLikesObj.splice(index,1);
         console.log("after splice: \n",newLikesObj);
         that.likes = newLikesObj;
         that.save(cb)

      }
});

并且从日志拼接似乎可以正常工作

and from logs splice seems to be working ok

before splice:
  [ { user: 5247095b5696e45c2b000102,
    _id: 524defc87153550829000103,
    createdAt: Fri Oct 04 2013 01:29:28 GMT+0300 (Финляндия (лето)) },
  { user: 5247095b5696e45c2b000002,
    _id: 524df3c2a663050805000003,
    createdAt: Fri Oct 04 2013 01:46:26 GMT+0300 (Финляндия (лето)) } ]
after splice:
 [ { user: 5247095b5696e45c2b000102,
    _id: 524defc87153550829000103,
    createdAt: Fri Oct 04 2013 01:29:28 GMT+0300 (Финляндия (лето)) } ]

静态方法:

getArticleByWithLikesByUserId: function (id, cb) {
    this.find({ 'likes.user' : id })
      .populate('user', 'name email username')
      .populate('comments.user')
      .exec(cb)
  }

我也尝试过这种更新方法，即使numberAffected显示为1，它仍然不会删除

I've also tried this update method, still doesnt remove like even though numberAffected is showing 1

this.update({$pull : {'likes.user':user.id}}, function(err, numberAffected){
    if(!err){
      return console.log('like removed');
    } else {
      return console.log(err);
    }
 });

推荐答案

我不能说您的示例出了什么问题，除了您使用错误的方式. MongoDB提供了一种更简单的内置方式，可以通过指定精确值或通过查询从数组中删除项目:

I can't say what's going wrong with your example, other than that you're going about it the wrong way. MongoDB provides an an easier, built in way to remove items from an array either by specifying the exactly, or via a query:

看到 $pull运算符.

用猫鼬做这件事的一种方法是:

In mongoose one way to do this would be:

Article.findByIdAndUpdate(this._id, {
  $pull: {
    likes: {user: user._id}
  }
}, cb);

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