弹性搜索不同的过滤器值 [英] Elasticsearch distinct filter values

问题描述

我在弹性搜索中有一个大文件存储，并且想要检索显示在HTML下拉列表中的不同的过滤器值。

一个例子就是像/ p>

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

下拉列表应该有一个部门列表，即IT，帐户和管理。

有些人请指出正确的方向，从弹性搜索中检索不同的部门清单？

感谢

解决方案

这是一个条款的工作 a href =http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-bucket-terms-aggregation.html#search-aggregations-bucket-terms-aggregation =nofollow >文档）。

您可以拥有独特的部门这样的值：

  POST公司/员工/ _search 
 {
size：0，
aggs {
by_departments：{
terms：{
field：departments.name，
size：0 // see note 1 
} 
} 
} 
} 
  

输出：

  {
 ... 
聚合：{
 by_departmen ts：{
buckets：[
 {
key：管理，//参见注释2 
doc_count：2 
} 
 {
key：accounts，
doc_count：1 
}，
 {
key：it b $ bdoc_count：1 
} 
] 
} 
} 
} 
  

另外两个注释：

• 设置 size 为0将把最大值设置为Integer.MAX_VALUE。不要使用它，如果有太多的部门不同的值。


• 你可以看到钥匙是分析部门的条款。确保在映射为 not_analyzed 的字段上使用术语聚合。






例如，使用我们的默认映射（ departments.name 是一个分析 string），添加此员工：

  {
name：Bill Gates，
department：[
 {
name：IT
}，
 {
name：人力资源
 } 
] 
} 
  

将导致这种结果：

  {
 ... 
聚合：{
by_departments：{
buckets：[
 {
key：it，
doc_count：2 
}，
 {
key ：管理，
doc_count：2 
}，
 {
key：accounts，
doc_count：1 
 }，
 {
key：human，
doc_count：1 
}，
 {
key：resource，
 doc_count：1 
} 
] 
} 
} 
} 
  

使用正确的映射：

  POST公司
 {
映射：{
employee：{
properties：{
name：{
type：string
}，
department：{
type：object，
properties：{
name：{
type：string，
index：not_analyzed
} 
} 
} 
} 
} 
} 
} 
  

同样的请求最终输出：

  {
 ... 
aggregate：{
by_departments：{
buckets：[
 {
key：IT，
doc_count：2 
}，
 {
key：管理，
 doc_count：2 
}，
 {
key：Accounts，
doc_count：1 
}，
 {
key：人力资源，
doc_count：1 
} 
] 
} 
} 
} 
  

希望这有帮助！




I have a large document store in elasticsearch and would like to retrieve the distinct filter values for display on HTML drop-downs.

An example would be something like

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

The drop-down should have a list of departments, i.e. IT, Account and Management.

Would some kind person please point me in the right direction for retrieving a distinct list of departments from elasticsearch?

Thanks

解决方案

This is a job for a terms aggregation (documentation).

You can have the distinct departments values like this :

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

Which, in your example, outputs :

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

Two additional notes :

• setting size to 0 will set the maximum buckets number to Integer.MAX_VALUE. Don't use it if there are too many departments distinct values.
• you can see that the keys are terms resulting of analyzing departments values. Be sure to use your terms aggregation on a field mapped as not_analyzed .

For example, with our default mapping (departments.name is an analyzed string), adding this employee:

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

will cause this kind of result:

{
   ...
   "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
            }
         ]
      }
   }
}

With a correct mapping :

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

The same request ends up outputting :

{
   ...
   "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
            }
         ]
      }
   }
}

Hope this helps!

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