elasticsearch - 如何获取elasticsearch索引中的所有字段名

Question

我刚开始使用 elasticsearch 5.2。

我正在尝试获取索引中的所有键 如果我有以下映射:

"properties": {
         "name": { "type": "text" },
         "article": {
          "properties": {
           "id": { "type": "text" },
           "title":  { "type": "text"},
           "abstract": { "type": "text"},
            "author": {
             "properties": {
              "id": { "type": "text" },
              "name": { "type": "text" }
}}}} } }

是否可以获取所有字段的全名？ 像这样:

 name,
 article.id ,
 article.title ,
 article.abstract ,
 article.author.id,
 article.author.name

我怎样才能得到它？

Answer 1

您可以使用 _field_names字段。

The _field_names field indexes the names of every field in a document that contains any value other than null.

GET _search
{
  "size"0,
  "aggs": {
    "Field names": {
      "terms": {
        "field": "_field_names", 
        "size": 100
      }
    }
  }
}

更新:从 ES 5 开始

the _field_names field has been locked down and is only indexed, it doesn't support fielddata (memory intensive) or doc values,

引用:https://github.com/elastic/elasticsearch/issues/22576

作为替代方案，您可以 getMapping API

The get mapping API can be used to get more than one index or type mapping with a single call. General usage of the API follows the following syntax: host:port/{index}/_mapping/{type}

$ curl -XGET 'http://localhost:9200/index/_mapping?pretty'

然后您可以处理响应以提取索引中的所有字段名称