如何在Elasticsearch中实现First_value和Last_Value SQL函数？

GET /your_index/_search
{
  "size": 0,
  "aggs": {
    "group_by_field": {
      "terms": {
        "field": "your_group_by_field",
        "size": 10,
        "order": {
          "_key": "asc"
        }
      },
      "aggs": {
        "first_doc": {
          "top_hits": {
            "size": 1,
            "sort": [
              {
                "your_sort_field": {
                  "order": "asc"
                }
              }
            ]
          }
        },
        "last_doc": {
          "top_hits": {
            "size": 1,
            "sort": [
              {
                "your_sort_field": {
                  "order": "desc"
                }
              }
            ]
          }
        }
      }
    }
  }
}