Elasticsearch 获得平均

问题描述

我正在尝试对 elasticsearch 上的聚合数据进行平均。这是我的数据结构：

文档 1

{
   "groupId":"TEST_01","lag":10,"detectionDate":"2021-02-26T21:42:30.010Z","tipo":"uno","topics":[
      {
         "name":"topic_01","valore":2
      },{
         "name":"topic_02","valore":4
      }
   ]
}

文档 2

{
   "groupId":"TEST_01","valore":4
      },"valore":8
      }
   ]
}

我必须按 groupId 和主题名称创建聚合，并在此聚合上计算值字段的平均值。但是用源码试了一下，得到的平均值结果是错误的。

有了以上文档一和二的数据，预期的结果应该是：

groupId	topicName	平均
TEST_01	topic_01	3
TEST_01	topic_02	6

TermsAggregationBuilder aggregation = AggregationBuilders
    .terms("groupId")
    .field("groupId.keyword")
        .subAggregation(AggregationBuilders
            .terms("topicName")
            .field("topics.name.keyword").subAggregation(AggregationBuilders
                .avg("avg").field("topics.valore")));

解决方法

首先确保您的主题字段类型为“嵌套”，因为如果它是“对象”，则 topicName 和 valores 将被扁平化。这意味着您最终会得到一组 valores 和 topicNames，它们之间没有关系。

映射

{
  "test_ynsanity" : {
    "mappings" : {
      "properties" : {
        "detectionDate" : {
          "type" : "date"
        },"groupId" : {
          "type" : "text","fields" : {
            "keyword" : {
              "type" : "keyword","ignore_above" : 256
            }
          }
        },"lag" : {
          "type" : "long"
        },"tipo" : {
          "type" : "text","topics" : {
          "type" : "nested","properties" : {
            "name" : {
              "type" : "text","fields" : {
                "keyword" : {
                  "type" : "keyword","ignore_above" : 256
                }
              }
            },"valore" : {
              "type" : "long"
            }
          }
        }
      }
    }
  }
}

提取数据

POST test_ynsanity/_doc
{
   "groupId":"TEST_01","lag":10,"detectionDate":"2021-02-26T21:42:30.010Z","tipo":"uno","topics":[
      {
         "name":"topic_01","valore":2
      },{
         "name":"topic_02","valore":4
      }
   ]
}

POST test_ynsanity/_doc
{
   "groupId":"TEST_01","valore":4
      },"valore":8
      }
   ]
}

查询

POST test_ynsanity/_search
{
  "size": 0,"aggs": {
    "groups": {
      "terms": {
        "field": "groupId.keyword","size": 10
      },"aggs": {
        "topics": {
          "nested": {
            "path": "topics"
          },"aggs": {
            "topic_names": {
              "terms": {
                "field": "topics.name.keyword"
              },"aggs": {
                "topic_avg": {
                  "avg": {
                    "field": "topics.valore"
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

回复

{
  "took" : 1,"timed_out" : false,"_shards" : {
    "total" : 1,"successful" : 1,"skipped" : 0,"failed" : 0
  },"hits" : {
    "total" : {
      "value" : 2,"relation" : "eq"
    },"max_score" : null,"hits" : [ ]
  },"aggregations" : {
    "groups" : {
      "doc_count_error_upper_bound" : 0,"sum_other_doc_count" : 0,"buckets" : [
        {
          "key" : "TEST_01","doc_count" : 2,"topics" : {
            "doc_count" : 4,"topic_names" : {
              "doc_count_error_upper_bound" : 0,"buckets" : [
                {
                  "key" : "topic_01","NAME" : {
                    "value" : 3.0
                  }
                },{
                  "key" : "topic_02","NAME" : {
                    "value" : 6.0
                  }
                }
              ]
            }
          }
        }
      ]
    }
  }
}

我现在无法访问 Java DSL，但查询应如下所示：

TermsAggregationBuilder aggregation = AggregationBuilders
    .terms("groupId")
    .field("groupId.keyword")
        .subAggregation(AggregationBuilders
            .nested("agg","topics")
            .terms("topic_names")
            .field("topics.name.keyword").subAggregation(AggregationBuilders
                .avg("avg").field("topics.valore")));