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elasticsearch - 只返回搜索结果的唯一值 - Elasticsearch

问题描述

我只想在查询中返回唯一的 _source 值。现在，下面的查询返回一堆对象，"_source": {"serviceTitle": "Blood Count" }我希望它只返回一个。

我有一个这样的查询：

{
    "_source": ["serviceTitle"],
    "size": 5,
    "query": {
        "multi_match": {
            "query": "blood count",
            "type": "bool_prefix", 
            "fields": [ 
                "serviceTitle",
                "serviceTitle._2gram",
                "serviceTitle._3gram"
                
            ]
        }
      }
  }

将返回这个：


    "took": 317,
    "timed_out": false,
    "_shards": {
        "total": 5,
        "successful": 5,
        "skipped": 0,
        "failed": 0
    },
    "hits": {
        "total": {
            "value": 297,
            "relation": "eq"
        },
        "max_score": 7.6956334,
        "hits": [
            {
                "_index": "recommendation-charlie",
                "_type": "_doc",
                "_id": "service_14815",
                "_score": 7.6956334,
                "_source": {
                    "serviceTitle": "Blood Count"
                }
            },
            {
                "_index": "recommendation-charlie",
                "_type": "_doc",
                "_id": "service_17946",
                "_score": 7.6956334,
                "_source": {
                    "serviceTitle": "Blood Count"
                }
            },
            {
                "_index": "recommendation-charlie",
                "_type": "_doc",
                "_id": "service_1459",
                "_score": 7.551247,
                "_source": {
                    "serviceTitle": "Blood Count"
                }
            }
        ]
    }
}

我想尽可能少地更改我的初始查询，我知道我可能可以这样做，aggs:但这迫使我更改查询的其他部分。任何帮助，将不胜感激！

标签： elasticsearch

解决方案

它并不像您希望的那样简单。最简单的方法是：

  1. 删除索引并调整映射如下：
PUT recommendation-charlie
{
  "mappings": {
    "properties": {
      "citations": {
        "type": "text",
        "fields": {
          "keyword": {
            "type": "keyword",
            "ignore_above": 256
          }
        }
      },
      "serviceTitle": {                     <---
        "type": "text",
        "fields": {
          "as_i_type": {                    <---
            "type": "search_as_you_type",
            "max_shingle_size": 3
          },
          "keyword": {                      <---
            "type": "keyword"
          }
        }
      }
    }
  }
}
  1. 重新索引您的文档
  2. 搜索该.as_i_type字段（更多关于这里的多字段）但汇总.keyword：
POST recommendation-charlie/_search
{
  "_source": [
    "serviceTitle"
  ],
  "size": 5,
  "query": {
    "multi_match": {
      "query": "blood count",
      "type": "bool_prefix",
      "fields": [
        "serviceTitle.as_i_type",           <---
        "serviceTitle.as_i_type._2gram",
        "serviceTitle.as_i_type._3gram"
      ]
    }
  },
  "aggs": {
    "by_unique_titles": {
      "terms": {
        "field": "serviceTitle.keyword",
        "order": {
          "max_score": "desc"
        }
      },
      "aggs": {
        "max_score": {
          "max": {
            "script": "_score"
          }
        }
      }
    }
  }
}

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