在MongoDB中插入或更新多个文档 [英] Insert or update multiple documents in MongoDB

问题描述

我想在NodeJS和MongoDB支持下实现标签功能，这样我也可以计算出用途.每当用户将标签添加到页面时，我都希望在数据库中推送或更新标签.每个hastag看起来都像这样:

I want to implement hashtags functionality with NodeJS and MongoDB support, so that I can also count the uses. Whenever a user adds hashtags to a page, I want to push or update them in the database. Each hastag looks like this:

{_id:<auto>, name:'hashtag_name', uses: 0}

我面临的问题是用户也可以添加新标签，因此当他单击完成"时，我必须为现有标签增加使用"字段，然后添加新标签.诀窍是如何仅用一条Mongo指令执行此操作?到目前为止，我想到了两种可能的方法来实现这一目标，但是我对这两种方法都不满意:

The problem I'm facing is that the user can add new tags as well, so when he clicks 'done', I have to increment the 'uses' field for the existing tags, and add the new ones. The trick is how to do this with only one Mongo instruction? So far I thought of 2 possible ways of achieving this, but I'm not particularly happy with either:

选项1

我有一项服务，可以在用户开始编写新文章之前从db获取现有标签.基于此，我可以检测到哪些标签是新标签，然后运行2个查询:一个将添加新标签，另一个将更新现有标签

I have a service which fetches the existing tags from the db before the user starts to write a new article. Based on this, I can detect which tags are new, and run 2 queries: one which will add the new tags, and another which will update the existing one

选项2

我将标签列表发送到服务器，然后在其中为每个标签运行find()；如果找到一个，我将进行更新，否则，将创建它.

I will send the list of tags to the server, and there I will run a find() for every tag; if I found one, I'll update, if not, I'll create it.

选项3 (暂时没有解决方案)

Option 3 (without solution for now)

最好的选择是运行一个查询，该查询采用标记名数组，对现有标记名执行$ inc操作，然后添加缺失的标记.

Best option would be to run a query which takes an array of tag names, do a $inc operation for the existing ones, and add the missing ones.

问题

有更好的解决方案吗?我可以从选项3获得最终结果吗?

Is there a better solution? Can I achieve the end result from option #3?

推荐答案

您应该执行以下操作，所有这些操作都将在一批中执行，这只是如何执行的摘要代码:

You should do something like this, all of them will be executed in one batch, this is only an snippet idea how to do it:

var db = new Db('DBName', new Server('localhost', 27017));
    // Establish connection to db
    db.open(function(err, db) {
    // Get the collection
    var col = db.collection('myCollection');

    var batch = col.initializeUnorderedBulkOp();

    for (var tag in hashTagList){
      // Add all tags to be executed (inserted or updated) 
      batch.find({_id:tag.id}).upsert().updateOne({$inc: {uses:1}});
    }

    batch.execute(function(err, result) {
      db.close();
    });
  });

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