MongoDB的 - 检索阵列集

问题描述

什么似乎一个简单的任务，前来对我来说是一个挑战。

what seemed a simple task, came to be a challenge for me.

我有以下MongoDB的结构：

I have the following mongodb structure:

{
(...)
"services": {
    "TCP80": {
      "data": [{
          "status": 1,
          "delay": 3.87,
          "ts": 1308056460
        },{
          "status": 1,
          "delay": 2.83,
          "ts": 1308058080
        },{
          "status": 1,
          "delay": 5.77,
          "ts": 1308060720
        }]
    }
}}

现在，下面的查询将返回整个文档：

Now, the following query returns whole document:

{ 'services.TCP80.data.ts':{$gt:1308067020} }

我不知道 - 有可能是我只接收那些数据数组匹配$ GT标准（一种收缩DOC）的作品

我正在考虑马preduce，但无法找到如何通过外部参数（时间戳）到map（）函数甚至一个例子。 （此功能在1.1.4 ）

I was considering MapReduce, but could not locate even a single example on how to pass external arguments (timestamp) to Map() function. (This feature was added in 1.1.4 https://jira.mongodb.org/browse/SERVER-401)

此外，总有写storedJs功能的替代品，但因为我们讲的大量数据中，DB-锁在这里不能忍受的。

Also, there's always an alternative to write storedJs function, but since we speak of large quantities of data, db-locks can't be tolerated here.

最有可能我得的结构重新设计的东西1级深，如：

Most likely I'll have to redesign the structure to something 1-level deep, like:

{
   status:1,delay:3.87,ts:138056460,service:TCP80
},{
   status:1,delay:2.83,ts:1308058080,service:TCP80
},{
   status:1,delay:5.77,ts:1308060720,service:TCP80
}

但DB将大幅增长，因为服务只是将每个文档添加许多选项之一。

but DB will grow dramatically, since "service" is only one of many options which will append each document.

请指教！

在此先感谢

推荐答案

这是目前不支持。默认情况下，除非你使用领域限制或$切片运营商，您将永远得到整个文档/阵列。目前这些工具不允许基于所述搜索标准过滤数组元素

This is not currently supported. By default you will always receive the whole document/array unless you use field restrictions or the $slice operator. Currently these tools do not allow filtering the array elements based on the search criteria.

您应该看一个办法做到这一点这个请求：

You should watch this request for a way to do this: https://jira.mongodb.org/browse/SERVER-828

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