如何通过分组solr中的天数来获得列的总和

Question

我的solr数据如下:

{
      {
        "total_amount": 100,
        "created_at": "2015-07-08T18:30:00Z"
      },
      {
        "total_amount": 200,
        "created_at": "2015-07-08T18:30:00Z"
      },
      {
        "total_amount": 300,
        "created_at": "2015-06-08T18:30:00Z"
      },
      {
        "total_amount": 400,
        "created_at": "2015-06-08T18:30:00Z"
      }
}

我希望通过分组月份得到total_amount的总和.所以输出响应如下:

{
  "2015-07-01T00:00:00Z" : 300,
  "2015-06-01T00:00:00Z" : 700
}

我正在使用下面的查询来获取给定的响应,但它只给出了我的出现次数.

查询和响应如下:

{
    "responseHeader": {
    "status": 0,
    "QTime": 2,
    "params": {
    "facet.date.start": "2015-04-01T00:00:00Z",
    "facet": "true",
    "fl": "created_at,total_amount",
    "q": "campaign_id:1",
    "facet.date": "created_at",
    "facet.date.gap": "+1MONTH",
    "wt": "json",
    "facet.date.end": "2015-09-01T00:00:00Z"
    }
    },
    "response": {
    "numFound": 3,
    "start": 0,
    "docs": [
    {
    "total_amount": 100,
    "created_at": "2015-07-08T18:30:00Z"
    },
    {
    "total_amount": 100,
    "created_at": "2015-07-08T18:30:00Z"
    },
    {
    "total_amount": 100,
    "created_at": "2015-07-08T18:30:00Z"
    }
    ]
    },
    "facet_counts": {
    "facet_queries": {},
    "facet_fields": {},
    "facet_dates": {
    "created_at": {
    "2015-04-01T00:00:00Z": 0,
    "2015-05-01T00:00:00Z": 0,
    "2015-06-01T00:00:00Z": 0,
    "2015-07-01T00:00:00Z": 3,
    "2015-08-01T00:00:00Z": 0,
    "gap": "+1MONTH",
    "start": "2015-04-01T00:00:00Z",
    "end": "2015-09-01T00:00:00Z"
    }
    },
    "facet_ranges": {},
    "facet_intervals": {},
    "facet_heatmaps": {}
    }

}

Answer 1

像 sum 这样的运算不能用 Groping 算出...

尝试使用http://wiki.apache.org/solr/StatsComponent