概述

继续跟中华石杉老师学习ES，第44篇

课程地址： https://www.roncoo.com/view/55

案例

需求： 颜色+品牌下钻分析时按最深层metric进行排序

先看下默认的排序规则：

GET /tvs/sales/_search
{
  "aggs": {
    "group_by_color": {
      "terms": {
        "field": "color"
      },
      # 在color这个bucket下 下钻 品牌
      "aggs": {
        "group_by_brand": {
          "terms": {
            "field": "brand"
          },
          # 在brand这个b下 bcketmetrics 求 avg
          "aggs": {
            "avg_price": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  },
  "size": 0
}

返回：

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 8,
    "max_score": 0,
    "hits": []
  },
  "aggregations": {
    "group_by_color": {
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        {
          "key": "红色",
          "doc_count": 4,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "长虹",
                "doc_count": 3,
                "avg_price": {
                  "value": 1666.6666666666667
                }
              },
              {
                "key": "三星",
                "doc_count": 1,
                "avg_price": {
                  "value": 8000
                }
              }
            ]
          }
        },
        {
          "key": "绿色",
          "doc_count": 2,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "TCL",
                "doc_count": 1,
                "avg_price": {
                  "value": 1200
                }
              },
              {
                "key": "小米",
                "doc_count": 1,
                "avg_price": {
                  "value": 3000
                }
              }
            ]
          }
        },
        {
          "key": "蓝色",
          "doc_count": 2,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "TCL",
                "doc_count": 1,
                "avg_price": {
                  "value": 1500
                }
              },
              {
                "key": "小米",
                "doc_count": 1,
                "avg_price": {
                  "value": 2500
                }
              }
            ]
          }
        }
      ]
    }
  }
}

截取下Red 来看下默认的排序规则 （doc_count 降序）

如果想按照平均价格 降序排列呢？ 我们这里有2层下钻，而平均价格是在第二层下钻里 ，即我们这里的主题【按最深层metric进行排序】

GET /tvs/sales/_search
{
  "aggs": {
    "group_by_color": {
      "terms": {
        "field": "color"
      },
      "aggs": {
        "group_by_brand": {
          "terms": {
            "field": "brand",
            "order": {
              "avg_price": "desc"
            }
          },
          "aggs": {
            "avg_price": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  },
  "size": 0
}

返回结果：

{
  "took": 2,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": 8,
    "max_score": 0,
    "hits": []
  },
  "aggregations": {
    "group_by_color": {
      "doc_count_error_upper_bound": 0,
      "sum_other_doc_count": 0,
      "buckets": [
        {
          "key": "红色",
          "doc_count": 4,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "三星",
                "doc_count": 1,
                "avg_price": {
                  "value": 8000
                }
              },
              {
                "key": "长虹",
                "doc_count": 3,
                "avg_price": {
                  "value": 1666.6666666666667
                }
              }
            ]
          }
        },
        {
          "key": "绿色",
          "doc_count": 2,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "小米",
                "doc_count": 1,
                "avg_price": {
                  "value": 3000
                }
              },
              {
                "key": "TCL",
                "doc_count": 1,
                "avg_price": {
                  "value": 1200
                }
              }
            ]
          }
        },
        {
          "key": "蓝色",
          "doc_count": 2,
          "group_by_brand": {
            "doc_count_error_upper_bound": 0,
            "sum_other_doc_count": 0,
            "buckets": [
              {
                "key": "小米",
                "doc_count": 1,
                "avg_price": {
                  "value": 2500
                }
              },
              {
                "key": "TCL",
                "doc_count": 1,
                "avg_price": {
                  "value": 1500
                }
              }
            ]
          }
        }
      ]
    }
  }
}

同样的，我们也截取下Red 来看下默认的排序规则 （doc_count 降序）

已经按照我们指定的 avg_price 降序排列啦。