elasticsearch - ElasticSearch:是否可以在搜索请求期间生成 “Temporary Field”？

Question

样本文件:

{
    "text": "this is my text",
    "categories": [
        {"category": "sample category"},
        {"category": "local news"}
    ]
}

当前的映射为:

{
    "topic": {
        "properties": {
            "categories": {
                "properties": {
                    "category": {
                        "type": "string",
                        "store": "no",
                        "term_vector": "with_positions_offsets",
                        "analyzer": "ik_max_word",
                        "search_analyzer": "ik_max_word",
                        "include_in_all": "true",
                        "boost": 8,
                        "fields": {
                            "raw": {
                                "type": "string",
                                "index": "not_analyzed"
                            }
                        }
                    }
                }
            }
        }
    }
}

搜索查询:

{
    "_source": false,
    "query":{
        "match":{
            "categories.category":"news"
        }
    },
    "aggs": {
        "match_count": {
            "terms" : {"field": "categories.category.raw"}
        }
    }
}

我想要的结果是:

{
    ...
    "buckets": [
        {
            "key": "local news",
            "doc_count": 1
        } 

    ]
    ...
}

结果实际上是(它汇总了所有匹配文档的category.category):

{
    ...
    "buckets": [
        {
            "key": "local news",
            "doc_count": 1
        },{
            "key": "sample category", //THIS PART IS NOT NEEDED
            "doc_count": 1
        }
    ]
    ...
}

在搜索过程中是否可以添加 temporary field？在这种情况下，假设所有匹配的 categories.category都命名为 categories.match_category，并通过此临时字段 categories.match_category进行汇总？如果为真，我该怎么办？如果不可以，该怎么办？

Answer 1

以下是另一种方法，但它更符合您的需求逻辑:

映射

 {
    "topic": {
        "properties": {
            "categories": {
                "type":"nested",
            "properties": {
                    "category": {
                        "type": "string",
                        "store": "no",
                        "analyzer": "simple",
                        "include_in_all": "true",
                        "boost": 8,
                        "fields": {
                            "raw": {
                                "type": "string",
                                "index": "not_analyzed"
                            }
                        }
                    }
                }
            }
        }
    }
}

数据

{
    "text": "this is my text",
    "categories": [
        {"category": "sample category"},
        {"category": "local news"}
    ]
}

查询

{
  "query":{
    "nested":{
      "path":"categories",
      "query":{
        "filtered":{
          "query":{
            "match":{
              "categories.category":"news"
            }
          }
        }
      }
    }
  },
  "aggs": {
    "nest":{
      "nested":{
        "path":"categories"

      },
      "aggs":{
        "filt":{
          "filter" : {
            "script": {
              "script" : "doc['categories.category'].values.contains('news')"
            }
          },
          "aggs":{
            "match_count": {
              "terms" : {"field": "categories.category.raw"}
            }
          }
        }
      }
    }
  }
}

产生的结果

{
    "_shards": {
        "failed": 0, 
        "successful": 5, 
        "total": 5
    }, 
    "aggregations": {
        "nest": {
            "doc_count": 2, 
            "filt": {
                "doc_count": 1, 
                "match_count": {
                    "buckets": [
                        {
                            "doc_count": 1, 
                            "key": "local news"
                        }
                    ], 
                    "doc_count_error_upper_bound": 0, 
                    "sum_other_doc_count": 0
                }
            }
        }
    }, 
    "hits": {
        "hits": [], 
        "max_score": 0.0, 
        "total": 1
    }, 
    "timed_out": false, 
    "took": 3
}

这里的问题是您必须根据聚合中的脚本过滤器来创建自己的脚本，上面的示例在“类别”映射中使用一个简单的分析器为我工作