Elasticsearch 按嵌套对象的数量排序

Question

我有以下 ES 内容，基本上是一个包含网站嵌套报价的产品列表。

{
"product": {
  "ean": "abc",
  "features": {
     "product_type": "DVD player"
  },
  "color": "Black",
  "manufacturer": "Sony",
  "sitedetails": [
     {
        "name": "amazon.com",
        "sku": "zzz",
        "url": "http://www.amazon.com/dp/zzz"
     },
     {
        "name": "bestbuy.com",
        "sku": "aaa",
        "url": "http://www.bestbuy.com/aaa"
     }
  ],
  "category": "Portable DVD Players"
 },
 product: { etc etc},
 product: { etc etc},
}

如何按站点详细信息的数量排序？

谢谢!

Answer 1

您可以使用 Painless 来完成，因此您不必启用动态脚本。

{
  "sort": [{
    "_script": {
       "type": "number",
       "script": "params._source?.product?.sitedetails?.length ?: 0",
       "order": "desc"
     }
   }]
}

我还包括对空字段的处理。看 https://www.elastic.co/guide/en/elasticsearch/painless/master/_operators.html

https://github.com/elastic/elasticsearch/issues/20068