elasticsearch - 从ElasticSearch查询的日期字段中提取日期(yyyyMMdd)

Question

我的索引有一个日期字段，格式为2020-01-04T05:00:06.870000Z。在ES查询响应中，我需要yyyyMMdd形式的日期，所以20200104。我尝试使用脚本查询并分别提取了日期，月份和年份。我如何将它们串联在_source中以获得number形式的yyyyMMdd？
样本数据 :

 "_source": {
    "updated": "2020-01-04T05:00:06.870000Z"
  }
  "_source": {
    "updated": "2020-01-04T09:00:08.870000Z"
  }
  "_source": {
    "updated": "2019-12-04T01:00:06.870000Z"
  }
}

查询:

"sort" : [
        { 
            "_script": {
                "type": "number",
                "script": {
                    "lang": "painless",
                    "source": "doc['updated'].value.getYear()"  
//similarly use getMonthOfYear() and getDayOfMonth(). How to concatenate and convert to number ?
                },
                "order": "desc"
            }
        }
    ]

Answer 1

您可以使用String.format正确填写数字，然后使用Integer.parseInt填写结果。
另外，您可以执行以下操作:

GET dates/_search
{
  "sort": [
    {
      "_script": {
        "type": "number",
        "script": {
          "lang": "painless",
          "source": """
            Integer.parseInt(
              DateTimeFormatter
                .ofPattern("yyyyMMdd")
                .withZone(ZoneOffset.UTC)
                .format(Instant.ofEpochMilli(
                  doc['updated'].value.millis)
                ));
          """
        },
        "order": "desc"
      }
    }
  ]
}