编写脚本以从 Elasticsearch 获取 Distinct 值

Question

我想创建一个自定义的 distinct 函数，我可以在其中编写多个字段名称的简单 distinctBy 脚本，以便一起区分。那么 ElasticSearch 中是否有实现此目的的方法。

Answer 1

我所做的是在这个 concatenated 字段上使用 Terms Aggregation using Script to construct keys from three different fields and then apply Terms Aggregation 来提供您想要的内容。

我创建了一个包含 3 个字段（field1、field2 和 field3 类型 keyword）的示例索引，文档如下。您可以检查查询和结果部分以查看它们的显示方式。关键是结果部分的 keys 是不同的。

示例文档

POST myfieldindex/mydocs/1
{
  "field1": "Football",
  "field2": "Premier League",
  "field3": "Chelsea"
}

POST myfieldindex/mydocs/3
{
  "field1": "Football",
  "field2": "Premier League",
  "field3": "Liverpool"
}

POST myfieldindex/mydocs/3
{
  "field1": "Football",
  "field2": "Premier League",
  "field3": "ManCity"
}

查询

POST myfieldindex/_search
{  
   "size":0,
   "aggs":{  
      "myagg":{  
         "terms":{  
            "script":{  
               "source":"doc['field1'].value + params.param + doc['field2'].value + params.param + doc['field3'].value",
               "lang":"painless",
               "params":{  
                  "param":","
               }
            }
         }
      }
   }
}

查询结果

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 3,
    "max_score": 0,
    "hits": []
  },
  "aggregations": {
    "myagg": {
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        {
          "key": "Football,Premier League,Chelsea",
          "doc_count": 1
        },
        {
          "key": "Football,Premier League,Liverpool",
          "doc_count": 1
        },
        {
          "key": "Football,Premier League,ManCity",
          "doc_count": 1
        }
      ]
    }
  }
}

因此您可以在结果中看到 key 是如何构造的（键是唯一的）。

如果有帮助请告诉我！

编写脚本以从 Elasticsearch 获取 Distinct 值

Script writing to get Distinct value from Elasticsearch

elasticsearch

elasticsearch-painless

示例文档

查询

查询结果