elasticsearch的group by+avg+sort等聚合分析

本文依据如下数据模板进行分析

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

需求一：计算每个tag下的商品数据

GET /ecommerce/product/_search
{
  "aggs": {//聚合函数
    "group_by_tags": {//该名称可以随便起
      "terms": { "field": "tags" }
    }
  }
}

第一次运行此代码会报错，原因是field使用时要将fielddata属性设置为true，此属性左右后面在进行讲解：

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

需求二：对名称中包含yagao的商品，计算每个tag下的商品数量

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

需求三：先分组，再算每组的平均值，计算每个tag下的商品的平均价格

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

需求四：计算每个tag下的商品平均价格，并且按照平均价格降序排序

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

需求五：按照指定的价格范围区间进行分组，然后在每组内再按照tag进行分组，最后再计算每组的平均价格

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" } } } } } } } }