Elasticsearch 不同的过滤器值

我在 elasticsearch 中有一个大型文档存储，并且想要检索不同的过滤器值以显示在 HTML 下拉列表中。

一个例子是这样的

[
    {
        "name": "John Doe",
        "deparments": [
            {
                "name": "Accounts"
            },
            {
                "name": "Management"
            }
        ]
    },
    {
        "name": "Jane Smith",
        "deparments": [
            {
                "name": "IT"
            },
            {
                "name": "Management"
            }
        ]
    }
]  

下拉列表应包含部门列表，即 IT、客户和管理。

请有好心人为我指明从 Elasticsearch 检索不同部门列表的正确方向吗？

Thanks

这是一份工作terms聚合（文档 http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-bucket-terms-aggregation.html#search-aggregations-bucket-terms-aggregation).

你可以拥有与众不同的departments像这样的值：

POST company/employee/_search
{
  "size":0,
  "aggs": {
    "by_departments": {
      "terms": {
        "field": "departments.name",
        "size": 0 //see note 1
      }
    }
  }
}

在您的示例中，输出：

{
   ...
   "aggregations": {
      "by_departments": {
         "buckets": [
            {
               "key": "management", //see note 2
               "doc_count": 2
            },
            {
               "key": "accounts",
               "doc_count": 1
            },
            {
               "key": "it",
               "doc_count": 1
            }
         ]
      }
   }
}

两个附加说明：

• setting size设置为 0 会将最大存储桶数设置为 Integer.MAX_VALUE。如果太多就不要使用departments独特的价值观。
• 你可以看到钥匙是terms分析结果departments价值观。请务必使用您的terms映射为的字段上的聚合not_analyzed .

例如，使用我们的默认映射（departments.name is an analyzed字符串），添加该员工：

{
  "name": "Bill Gates",
  "departments": [
    {
      "name": "IT"
    },
    {
      "name": "Human Resource"
    }
  ]
}

会导致这样的结果：

{
   ...
   "aggregations": {
      "by_departments": {
         "buckets": [
            {
               "key": "it",
               "doc_count": 2
            },
            {
               "key": "management",
               "doc_count": 2
            },
            {
               "key": "accounts",
               "doc_count": 1
            },
            {
               "key": "human",
               "doc_count": 1
            },
            {
               "key": "resource",
               "doc_count": 1
            }
         ]
      }
   }
}

有了正确的映射：

POST company
{
  "mappings": {
    "employee": {
      "properties": {
        "name": {
          "type": "string"
        },
        "departments": {
          "type": "object",
          "properties": {
            "name": {
              "type": "string",
              "index": "not_analyzed"
            }
          }
        }
      }
    }
  }
}

相同的请求最终输出：

{
   ...
   "aggregations": {
      "by_departments": {
         "buckets": [
            {
               "key": "IT",
               "doc_count": 2
            },
            {
               "key": "Management",
               "doc_count": 2
            },
            {
               "key": "Accounts",
               "doc_count": 1
            },
            {
               "key": "Human Resource",
               "doc_count": 1
            }
         ]
      }
   }
}

希望这可以帮助！