在ElasticSearch中,如何将对象数组转换为字符串数组?

我不知道您使用的是哪种版本的ElasticSearch,但这里有一个基于 pipelines 在ES v5.0中引入了摄取节点。

• 1)A script 处理器用于从每个子对象中提取值并将其设置在另一个字段中(此处, sports )
• 2)上一个 sport 字段用删除 remove 处理器

您可以使用 Simulate pipeline API 要测试它:

POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "description": "random description",
    "processors": [
      {
        "script": {
          "lang": "painless",
          "source": "ctx.sports =[]; for (def item : ctx.sport) { ctx.sports.add(item.name)  }"
        }
      },
      {
        "remove": {
          "field": "sport"
        }
      }
    ]
  },
  "docs": [
    {
      "_index": "index",
      "_type": "doc",
      "_id": "id",
      "_source": {
        "name": "John Doe",
        "sport": [
          {
            "name": "surf",
            "since": "2 years"
          },
          {
            "name": "mountainbike",
            "since": "4 years"
          }
        ]
      }
    }
  ]
}

输出以下结果:

{
  "docs": [
    {
      "doc": {
        "_index": "index",
        "_type": "doc",
        "_id": "id",
        "_source": {
          "name": "John Doe",
          "sports": [
            "surf",
            "mountainbike"
          ]
        },
        "_ingest": {
          "timestamp": "2018-07-12T14:07:25.495Z"
        }
      }
    }
  ]
}

可能有更好的解决方案,因为我没有经常使用管道,或者您可以在将文档提交到您的ElasticSearch集群之前使用logstash过滤器来实现这一点。

有关管道的更多信息,请查看 reference documentation of ingest nodes .