Elasticsearch - 2019 年按嵌套字段排序答案

【问题标题】：Elasticsearch - Sorting by a nested field in 2019Elasticsearch - 2019 年按嵌套字段排序
【发布时间】：2019-10-25 08:36:57
【问题描述】：

所以我试图找出一种基于其嵌套文档的单个属性对文档进行排序的方法。例如，假设我有一个“视频”索引。每个视频都有一个视频所属类别的列表。每个类别都是一个嵌套文档，其中包含有关该类别的某些元数据，例如id，视图，slug。这是一个示例映射：

 "videos" : {
    "properties" : {
      "categories" : {
        "type" : "nested",
        "properties" : {
          "id" : {
            "type" : "integer"
          },
          "views" : {
            "type" : "integer"
          },
          "slug" : {
            "type" : "keyword"
          }
        }
      },
      "title" : {
        "type" : "text"
      },
    }
  }

这是一个示例文档：

  {
    "_index" : "videos",
    "_id" : "123",
    "_source" : {
      "title" : "this is a test video",
      "categories" : [
        {
          "id" : 3533,
          "slug" : "animals",
          "views" : 314
        },
        {
          "id" : 3564,
          "slug" : "comedy",
          "views" : 814
        },
        {
          "id" : 4072,
          "slug" : "politics",
          "views" : 80
        }
      ],
    }
  }

所以我想按特定类别的观看次数对视频进行排序。例如，按“喜剧”类别的观看次数以降序对视频进行排序。我已经在网上搜索了一个解决方案，但其中大多数似乎非常针对一个问题或使用过时的查询。

【问题讨论】：

标签： php sorting elasticsearch

【解决方案1】：

Ypu 需要使用嵌套过滤器。您可以获取更多信息https://qbox.io/blog/sorting-nested-fields-in-elasticsearch

GET videos/_search
{

  "sort": [
    {
      "categories.views": {
        "order": "asc",
        "nested": {
          "path": "categories",
          "filter": {
            "term": {
              "categories.slug": "comedy"
            }
          }
        }
      }
    }
  ]
}

结果

   "hits" : [
      {
        "_index" : "videos",
        "_type" : "_doc",
        "_id" : "uT6bRGsBFW2mvGhmMxUU",
        "_score" : null,
        "_source" : {
          "title" : "this is a test video",
          "categories" : [
            {
              "id" : 3533,
              "slug" : "animals",
              "views" : 314
            },
            {
              "id" : 3564,
              "slug" : "comedy",
              "views" : 814
            },
            {
              "id" : 4072,
              "slug" : "politics",
              "views" : 80
            }
          ]
        },
        "sort" : [
          814
        ]
      },
      {
        "_index" : "videos",
        "_type" : "_doc",
        "_id" : "uj6bRGsBFW2mvGhmXxWl",
        "_score" : null,
        "_source" : {
          "title" : "this is a test video",
          "categories" : [
            {
              "id" : 3533,
              "slug" : "animals",
              "views" : 314
            },
            {
              "id" : 3564,
              "slug" : "comedy",
              "views" : 900
            },
            {
              "id" : 4072,
              "slug" : "politics",
              "views" : 80
            }
          ]
        },
        "sort" : [
          900
        ]
      }
    ]

【讨论】：