Elasticsearch nested 嵌套字段排序（qbit）

前言

• 本文的例子来自铭毅天下，并得到了铭毅天下本人的指导
• 本文内容对 Elasticsearch 7.17 适用

示例

• 多商品在不同分类下有不同的排名，取某个分类下的topN
• 创建 mappings

PUT products
{
  "mappings": {
    "properties": {
      "product_id": {
        "type": "integer"
      },
      "product_name": {
        "type": "keyword"
      },
      "categories": {
        "type": "nested",
        "properties": {
          "category_name": {
            "type": "keyword"
          },
          "rank": {
            "type": "integer"
          }
        }
      }
    }
  }
}

• 写入样例数据

POST /products/_bulk
{"index":{"_id":1}}
{"product_id":1,"product_name":"智能手机","categories":[{"category_name":"A","rank":1},{"category_name":"B","rank":3},{"category_name":"C","rank":2}]}
{"index":{"_id":2}}
{"product_id":2,"product_name":"耳机","categories":[{"category_name":"A","rank":4},{"category_name":"B","rank":1},{"category_name":"C","rank":3}]}
{"index":{"_id":3}}
{"product_id":3,"product_name":"便携式充电器","categories":[{"category_name":"A","rank":2},{"category_name":"B","rank":5},{"category_name":"C","rank":1}]}
{"index":{"_id":4}}
{"product_id":4,"product_name":"智能手表","categories":[{"category_name":"A","rank":3},{"category_name":"B","rank":2},{"category_name":"C","rank":4}]}

• 铭毅天下 给的参考查询语句，用到了聚合

GET products/_search
{
  "size": 0,
  "aggs": {
    "filtered_category": {
      "nested": {
        "path": "categories"
      },
      "aggs": {
        "category_name": {
          "filter": {
            "term": {
              "categories.category_name": "A"
            }
          },
          "aggs": {
            "top_products": {
              "top_hits": {
                "size": 3,
                "sort": [
                  {
                    "categories.rank": {
                      "order": "asc"
                    }
                  }
                ]
              }
            }
          }
        }
      }
    }
  }
}

• 参考ES nested 字段排序官方示例不用聚合的查询语句

GET products/_search
{
  "sort": [
    {
      "categories.rank": {
        "order": "asc",
        "nested": {
          "path": "categories",
          "filter": {
            "term": {
              "categories.category_name": "A"
            }
          }
        }
      }
    }
  ],
  "size": 3
}

相关文献

• Elasticsearch Nested 选型，先看这一篇！
• Elasticsearch 8.X 如何依据 Nested 嵌套类型的某个字段进行排序？

本文出自 qbit snap