Elasticsearch 按嵌套字段的最小值分组和排序

Question

我有一个在不同商店以不同价格提供的产品结构：

[{
  "name": "SomeProduct",
  "store_prices": [
    {
      "store": "FooStore1",
      "price": 123.45
    },
    {
      "store": "FooStore2",
      "price": 345.67
    }
  ]
},{
  "name": "OtherProduct",
  "store_prices": [
    {
      "store": "FooStore1",
      "price": 456.78
    },
    {
      "store": "FooStore2",
      "price": 234.56
    }
  ]
}]

我想显示一个产品列表，按最低价格升序排列，限制为 10 个结果，这样：

一些产品：123.45 美元
其他产品：234.56 美元

如何做到这一点？我尝试了 https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-nested-aggregation.html 中描述的嵌套聚合方法，但它只是 returns 所有产品的最低价格，而不是每个产品各自的最低价格：

{
  "_source": [
    "name",
    "store_prices.price"
  ],
  "query": {
    "match_all": {}
  },
  "sort": {
    "store_prices.price": "asc"
  },
  "aggs": {
    "stores": {
      "nested": {
        "path": "store_prices"
      },
      "aggs": {
        "min_price": {"min": {"field": "store_prices.price"}}
      }
    }
  },
  "from": 0,
  "size": 10
}

在 SQL 中，我想做的事情可以使用以下查询来描述。怕是我想多了"in sql":

SELECT
  p.name,
  MIN(s.price) AS price
FROM
  products p
INNER JOIN
  store_prices s ON s.product_id = p.id
GROUP BY
  p.id
ORDER BY
  price ASC
LIMIT 10

Answer 1

你需要 nested sorting:

{
   "query": // HERE YOUR QUERY,
   "sort": {
     "store_prices.price": {
       "order" : "asc",
       "nested_path" : "store_prices",
       "nested_filter": {
          // HERE THE FILTERS WHICH ARE EVENTUALLY 
          // FILTERING OUT SOME OF YOUR STORES
       }
     }
   }
}

请注意，您必须在嵌套筛选字段中重复最终的嵌套查询。然后您会在响应的 score 字段中找到价格。

Elasticsearch 按嵌套字段的最小值分组和排序

Elasticsearch group and order by nested field's min value

sorting

nested

aggregation

elasticsearch