elasticsearch 使用NEST和ElasticSearch每天统计文档数

我正在尝试使用NEST实现ElasticSearch查询，以便能够生成键/值对的结果，其中键是日期，值是计数。我查询的所有文档都有一个创建日期，我想计算在过去7天或类似时间内每天插入的文档数量

我已经检查了IElasticClient的计数方法，但这似乎给了我一个总计数，而不是每天。我想我需要对数据做一个方面的研究，但我不太清楚如何实现它

任何帮助都将不胜感激：）

您需要的是一个方面

以下是一个例子，其中应包括我可以解释您所需内容的各种方式：

export ELASTICSEARCH_ENDPOINT="http://localhost:9200"

# Index documents
curl -XPOST "$ELASTICSEARCH_ENDPOINT/_bulk?refresh=true" -d '
{"index":{"_index":"play","_type":"type","_id":1}}
{"created_date":"2013-09-30T12:00:00Z","key":"foo","count":12}
{"index":{"_index":"play","_type":"type","_id":2}}
{"created_date":"2013-09-30T13:00:00Z","key":"bar","count":14}
{"index":{"_index":"play","_type":"type","_id":3}}
{"created_date":"2013-10-01T12:00:00Z","key":"foo","count":42}
{"index":{"_index":"play","_type":"type","_id":4}}
{"created_date":"2013-10-01T14:00:00Z","key":"foo","count":13}
'


# Do searches

curl -XPOST "$ELASTICSEARCH_ENDPOINT/_search?pretty" -d '
{
    "facets": {
        "foos_per_interval": {
            "date_histogram": {
                "key_field": "created_date",
                "value_field": "count",
                "interval": "day"
            },
            "facet_filter": {
                "term": {
                    "key": "foo"
                }
            }
        }
    }
}
'

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "failed" : 0
  },
  "hits" : {
    "total" : 4,
    "max_score" : 1.0,
    "hits" : [ {
      "_index" : "play",
      "_type" : "type",
      "_id" : "1",
      "_score" : 1.0, "_source" : {"created_date":"2013-09-30T12:00:00Z","key":"foo","count":12}
    }, {
      "_index" : "play",
      "_type" : "type",
      "_id" : "2",
      "_score" : 1.0, "_source" : {"created_date":"2013-09-30T13:00:00Z","key":"bar","count":14}
    }, {
      "_index" : "play",
      "_type" : "type",
      "_id" : "3",
      "_score" : 1.0, "_source" : {"created_date":"2013-10-01T12:00:00Z","key":"foo","count":42}
    }, {
      "_index" : "play",
      "_type" : "type",
      "_id" : "4",
      "_score" : 1.0, "_source" : {"created_date":"2013-10-01T14:00:00Z","key":"foo","count":13}
    } ]
  },
  "facets" : {
    "foos_per_interval" : {
      "_type" : "date_histogram",
      "entries" : [ {
        "time" : 1380499200000,
        "count" : 1,
        "min" : 12.0,
        "max" : 12.0,
        "total" : 12.0,
        "total_count" : 1,
        "mean" : 12.0
      }, {
        "time" : 1380585600000,
        "count" : 2,
        "min" : 13.0,
        "max" : 42.0,
        "total" : 55.0,
        "total_count" : 2,
        "mean" : 27.5
      } ]
    }
  }
}

---

从各个方面着手确实是一条路：

公共类文档
{
公共字符串Id{get；set；}
public DateTime CreatedOn{get；set；}
}
public void TempFacetExample（）
{
var result=this.\u client.Search（s=>s
.FaceDateHistogram（fd=>fd
.OnField（p=>p.CreatedOn）
.Interval（DateInterval.Day）
//全局强制将其计算在范围之外
//来自主查询（如果有）
.Global（）
.FaceFilter（ff=>ff
.范围（rf=>rf
.From（DateTime.UtcNow.AddDays（-7））
.To（DateTime.UtcNow）
)
)
)
);
var facetBucket=result.Facet（p=>p.CreatedOn）；
//facetBucket.Items现在使用计数保存天数
//如果我没记错的话，elasticsearch不会返回空桶
//因此，您必须处理丢失的天数（没有文档）。
}

注意：该过滤器不可缓存。根据索引流和搜索模式，将特定于日期的索引划分为多个索引，只搜索相关日期的索引可能是一个好主意。我给了Martijn答案，因为问题是关于NEST的。但你的答案正是我想要的。非常感谢你！

public class Doc
{
    public string Id { get; set; }
    public DateTime CreatedOn { get; set; }
}

public void TempFacetExample()
{
    var result = this._client.Search<Doc>(s => s
        .FacetDateHistogram(fd => fd
            .OnField(p => p.CreatedOn)
            .Interval(DateInterval.Day)
            //global forces it to count out of scope
            //from the main query (if any)
            .Global()
            .FacetFilter(ff => ff
                .Range(rf => rf
                    .From(DateTime.UtcNow.AddDays(-7))
                    .To(DateTime.UtcNow)
                )
            )
        )
    );
    var facetBucket = result.Facet<DateHistogramFacet>(p => p.CreatedOn);
    //facetBucket.Items now holds the days with counts
    //if I remember correctly elasticsearch wont return empty buckets
    //so you have to handle missing days (that have no docs).

}