elasticsearch - 如何获取一条记录中多个匹配字段的命中数？

Question

我有类似的记录

{
    "who": "John",
    "hobby": [
        {"name": "gardening",
         "skills": 2
         },
        {"name": "sleeping",
         "skills": 3
         },
        {"name": "darts",
         "skills": 2
         }
    ]
}
,
{
    "who": "Mary",
    "hobby": [
        {"name": "gardening",
         "skills": 2
         },
        {"name": "volleyball",
         "skills": 3
         },
        {"name": "kung-fu",
         "skills": 2
         }
    ]
}

我正在考虑构建一个可以回答以下问题的查询:“我们有多少技能=2 的爱好？”

上面例子的答案是 3 ( "gardening" 对两者都是通用的，并且每个都有另一个独特的)。

每 "query"或 "query" + "aggs"我试过返回 ['hits']['hits']或 [ 'aggregations']['sources']['buckets']匹配数 文件 ，在上述情况下是两个(一个用于 "John" 和一个用于 "Mary" ，它们每个都满足查询)。

有没有办法构建一个查询，以便它返回与该查询匹配的字段总数(在上面的示例中:列表 "hobby" 的元素)？ (字段，而不是文档)

注意:如果我的文件是平的:

{"who": "John", "name": "gardening", "skills": 2},
{"who": "John", "name": "sleeping", "skills": 3},
(...)
{"who": "Mary", "name": "kung-fu", "skills": 2}

然后是一个简单的 "query"匹配“ skills": 2 + "name" 上的聚合将完成工作

Answer 1

是的，您可以使用 nested type 来实现此目的。并使用 inner_hits 和/或 nested aggregations .

所以这是您应该使用的映射:

curl -XPUT localhost:9200/hobbies -d '{
  "mappings": {
    "hob": {
      "properties": {
        "who": {
          "type": "string"
        },
        "hobby": {
          "type": "nested",      <--- the hobby list is of type nested
          "properties": {
            "name": {
              "type": "string",
              "index": "not_analyzed"
            },
            "skills": {
              "type": "integer"
            }
          }
        }
      }
    }
  }
}

然后我们可以使用 _bulk 插入您的两个示例文档。像这样的端点:

curl -XPOST localhost:9200/hobbies/hob/_bulk -d '
{"index":{}}
{"who":"John", "hobby":[{"name": "gardening","skills": 2},{"name": "sleeping","skills": 3},{"name": "darts","skills": 2}]}
{"index":{}}
{"who":"Mary", "hobby":[{"name": "gardening","skills": 2},{"name": "volley-ball","skills": 3},{"name": "kung-fu","skills": 2}]}
'

最后，我们可以查询你有多少爱好的索引 skills: 2像这样:

curl -XPOST localhost:9200/hobbies/hob/_search -d '{
  "_source": false,
  "query": {
    "nested": {
      "path": "hobby",
      "query": {
        "term": {
          "hobby.skills": 2
        }
      },
      "inner_hits": {}         <---- this will return only the matching nested fields with skills=2
    }
  },
  "aggs": {
    "hobbies": {
      "nested": {
        "path": "hobby"
      },
      "aggs": {
        "skills": {
          "filter": {
            "term": {
              "hobby.skills": 2
            }
          },
          "aggs": {
            "by_field": {         <--- this will return a breakdown of the fields with skills=2
              "terms": {
                "field": "name"
              }
            }
          }
        }
      }
    }
  }
}'

此查询将返回给您的是

在 hits部分，具有 skills: 2 的四个字段

在 aggs部分，具有 skills: 2 的 3 个不同字段的分割