用mongo db聚合框架求和 [英] Doing a sum with mongo db aggregation framework

问题描述

我在mongo db的集合中有以下类型的文档

I have the following kind of docs in a collection in mongo db

{   _id:xx, 
    iddoc:yy,   
    type1:"sometype1", 
    type2:"sometype2",
    date: 
    { 
      year:2015,
      month:4,
      day:29,
      type:"day"
    },
    count:23 
}

我想对所有文档的iddoc分组字段总计：

I would like to do a sum over the field count grouping by iddoc for all docs where:

• [ type1A， type1B，...]中的type1


• 其中，[[type2A， type2B中的type2 ...]


• date.year：2015年，


• date.month：4，


• date .type： day


• date.day 4到7之间

• type1 in ["type1A","type1B",...]
• where type2 in ["type2A","type2B",...]
• date.year: 2015,
• date.month: 4,
• date.type: "day"
• date.day between 4 and 7

我想要然后将这些总和排序。

I would like then to sort these sums.

我认为在mongo db聚合框架内这可能很容易做到，但我是新手，不胜感激。 / p>

I think this is probably easy to do within mongo db aggregation framework but I am new to it and would appreciate a tip to get started.

推荐答案

Th使用聚合管道：

db.test.aggregate([
  // Filter the docs based on your criteria
  {$match: {
    type1: {$in: ['type1A', 'type1B']},
    type2: {$in: ['type2A', 'type2B']},
    'date.year': 2015,
    'date.month': 4,
    'date.type': 'day',
    'date.day': {$gte: 4, $lte: 7}
  }},

  // Group by iddoc and count them
  {$group: {
    _id: '$iddoc',
    sum: {$sum: 1}
  }},

  // Sort by sum, descending
  {$sort: {sum: -1}}
])

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