在流星服务器上的mongodbdistinct()实现?

问题描述

我需要从Meteor的mongodb中获取不同的值(基本上，实现mongodb本机的distinct()调用).在客户端， Meteor是否有独特的集合查询?-这就像一个魅力.但是我不知道如何在服务器端获得类似的工作.感谢任何帮助.谢谢！

I need to fetch distinct values from the mongodb in Meteor (basically, implementing mongodb native distinct() call). On client side, Does Meteor have a distinct query for collections? - this works like a charm. But I can't figure out how to get something similar to work on the server side. Appreciate any help. Thanks!

推荐答案

好吧，在深入研究代码并意识到mongo lib包含所有必需方法的本机实现之后，我重用了 https://github.com/meteor/meteor/pull/644

Ok after some digging around the code and realizing mongo lib contains native implementations of all the needed methods I reused the aggregate() solution from https://github.com/meteor/meteor/pull/644

直接更改并将其翻译为coffeescript可以将以下代码段添加到服务器端代码中:

Straightforward changes and translation to coffeescript gives the following snippet to put into your server side code:

path = __meteor_bootstrap__.require("path")
MongoDB = __meteor_bootstrap__.require("mongodb")
Future = __meteor_bootstrap__.require(path.join("fibers", "future"))

myCollection = new Meteor.Collection "my_collection"

#hacky distinct() definition from https://github.com/meteor/meteor/pull/644
myCollection.distinct = (key)->
  future = new Future
  @find()._mongo.db.createCollection(@_name,(err,collection)=>
    future.throw err if err
    collection.distinct(key, (err,result)=>
      future.throw(err) if err
      future.ret([true,result])
      )
    )
  result = future.wait()
  throw result[1] if !result[0]
  result[1]

缺点是您必须为每个新集合定义它，但这很容易通过_.extend或我猜到的东西来修复另一个黑客.

Downside is you have to define it for every new collection but that's pretty straightforward to fix with another hack via _.extend or something I guess...

PS它现在也是一个智能软件包-mrt add mongodb-aggregation

PS It's also now a smart package - mrt add mongodb-aggregation

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