本文依據如下資料模板進行分析

PUT /ecommerce/product/1
{
    "name" : "gaolujie yagao",
    "desc" :  "gaoxiao meibai",
    "price" :  30,
    "producer" :      "gaolujie producer",
    "tags": [ "meibai", "fangzhu" ]
}

需求一：計算每個tag下的商品資料

GET /ecommerce/product/_search
{
  "aggs": {//聚合函式
    "group_by_tags": {//該名稱可以隨便起
 

      "terms": { "field": "tags" }
    }
  }
}

第一次執行此程式碼會報錯，原因是field使用時要將fielddata屬性設定為true，此屬性左右後面在進行講解：

PUT /ecommerce/_mapping/product
{
  "properties": {
    "tags": {
      "type": "text",
      "fielddata": true
    }
  }
}

需求二：對名稱中包含yagao的商品，計算每個tag下的商品數量

GET /ecommerce/product/_search
{
  "query"
 
: {
    "match": {
      "name": "yagao"
    }
  },
  "aggs": {
    "all_tags": {
      "terms": {
        "field": "tags"
      }
    }
  }
}

需求三：先分組，再算每組的平均值，計算每個tag下的商品的平均價格

GET /ecommerce/product/_search
{
    "size": 0,
    "aggs" : {
        "group_by_tags" : {
            "terms" : { "field"
 
 : "tags" },
            "aggs" : {
                "avg_price" : {
                    "avg" : { "field" : "price" }
                }
            }
        }
    }
}

需求四：計算每個tag下的商品平均價格，並且按照平均價格降序排序

GET /ecommerce/product/_search
{
    "aggs" : {
        "all_tags" : {
            "terms" : { "field" : "tags", "order": { "avg_price": "desc" } },
            "aggs" : {
                "avg_price" : {
                    "avg" : { "field" : "price" }
                }
            }
        }
    }
}

需求五：按照指定的價格範圍區間進行分組，然後在每組內再按照tag進行分組，最後再計算每組的平均價格

GET /ecommerce/product/_search
{
  "aggs": {
    "group_by_price": {
      "range": {
        "field": "price",
        "ranges": [
          {
            "from": 0,
            "to": 20
          },
          {
            "from": 20,
            "to": 40
          },
          {
            "from": 40,
            "to": 50
          }
        ]
      },
      "aggs": {
        "group_by_tags": {
          "terms": {
            "field": "tags"
          },
          "aggs": {
            "average_price": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  }
}