elasticsearch - 按字段大小对文档进行排序

Question

我有如下索引的文档，

1.

 {
"name": "Gilly",
"hobbyName" : "coin collection",
"countries": ["US","France","Georgia"]
}

2.

 {
"name": "Billy",
"hobbyName":"coin collection",
"countries":["UK","Ghana","China","France"]
}

现在我需要根据字段“countries”的数组长度对这些文档进行排序，这样排序后的结果就是document2，document1的顺序。我如何使用 elasticsearch 实现这一目标？

Answer 1

您可以使用 script based sorting实现这一目标。

{
   "query": {
      "match_all": {}
   },
   "sort": {
      "_script": {
         "type": "number",
         "script": "doc['countries'].values.size()",
         "order": "desc"
      }
   }
}