第一个分析需求:计算每个tag下的商品数量

将文本fieldfielddata属性设置为true
ES 7.X 命令:

  1. PUT /ecommerce/_mapping/
  2. {
  3. "properties": {
  4. "tags": {
  5. "type": "text",
  6. "fielddata": true
  7. }
  8. }
  9. }

在执行:

GET /ecommerce/_search
{
  "aggs": {
    "group_by_tags": {  # group_by_tags 只是一个名字, 随意定义
      "terms": { "field":"tags"}
    }
  },
  "size": 0
}
{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_tags" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "fangzhu",
          "doc_count" : 2
        },
        {
          "key" : "meibai",
          "doc_count" : 2
        },
        {
          "key" : "qingxin",
          "doc_count" : 2
        }
      ]
    }
  }
}

第二个聚合分析的需求:对名称中包含yagao的商品,计算每个tag下的商品数量

ES 7.x 命令, 其实 ES7.X 处理没有type 之外,整体的查询方式是和ES 5.X 是差不多的:

GET /ecommerce/_search
{
  "query": {
    "match": {
      "name": "yagao"
    }
  }, 
  "aggs": {
    "group_by_tags": {
      "terms": { "field":"tags"}
    }
  },
  "size": 0
}

结果:

{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_tags" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "fangzhu",
          "doc_count" : 2
        },
        {
          "key" : "meibai",
          "doc_count" : 2
        },
        {
          "key" : "qingxin",
          "doc_count" : 2
        }
      ]
    }
  }
}

第三个聚合分析的需求: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/_search
{
    "size": 0,
    "aggs" : {
        "group_by_tags" : {
            "terms" : { "field" : "tags" },
            "aggs" : {
                "avg_price" : {
                    "avg" : { "field" : "price" }
                }
            }
        }
    }
}

结果集:

{
  "took" : 22,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_tags" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "fangzhu",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 27.5
          }
        },
        {
          "key" : "meibai",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 40.0
          }
        },
        {
          "key" : "qingxin",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 45.0
          }
        }
      ]
    }
  }
}

第四个数据分析需求:计算每个tag下的商品的平均价格,并且按照平均价格降序排序

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

结果集:

{
  "took" : 5,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_tags" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "qingxin",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 45.0
          }
        },
        {
          "key" : "meibai",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 40.0
          }
        },
        {
          "key" : "fangzhu",
          "doc_count" : 2,
          "avg_price" : {
            "value" : 27.5
          }
        }
      ]
    }
  }
}

我们现在全部都是用es的restful api在学习和讲解es的所欲知识点和功能点,但是没有使用一些编程语言去讲解(比如java),原因有以下:
1、es最重要的api,让我们进行各种尝试、学习甚至在某些环境下进行使用的api,就是restful api。如果你学习不用es restful api,比如我上来就用java api来讲es,也是可以的,但是你根本就漏掉了es知识的一大块,你都不知道它最重要的restful api是怎么用的
2、讲知识点,用es restful api,更加方便,快捷,不用每次都写大量的java代码,能加快讲课的效率和速度,更加易于同学们关注es本身的知识和功能的学习
3、我们通常会讲完es知识点后,开始详细讲解java api,如何用java api执行各种操作
4、我们每个篇章都会搭配一个项目实战,项目实战是完全基于java去开发的真实项目和系统


第五个数据分析需求: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/_search
{
  "size": 0,
  "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": {
            "averge_price": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  }
}

结果集:

{
  "took" : 10,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_price" : {
      "buckets" : [
        {
          "key" : "0.0-20.0",
          "from" : 0.0,
          "to" : 20.0,
          "doc_count" : 0,
          "group_by_tags" : {
            "doc_count_error_upper_bound" : 0,
            "sum_other_doc_count" : 0,
            "buckets" : [ ]
          }
        },
        {
          "key" : "20.0-40.0",
          "from" : 20.0,
          "to" : 40.0,
          "doc_count" : 2,
          "group_by_tags" : {
            "doc_count_error_upper_bound" : 0,
            "sum_other_doc_count" : 0,
            "buckets" : [
              {
                "key" : "fangzhu",
                "doc_count" : 2,
                "averge_price" : {
                  "value" : 27.5
                }
              },
              {
                "key" : "meibai",
                "doc_count" : 1,
                "averge_price" : {
                  "value" : 30.0
                }
              }
            ]
          }
        },
        {
          "key" : "40.0-50.0",
          "from" : 40.0,
          "to" : 50.0,
          "doc_count" : 1,
          "group_by_tags" : {
            "doc_count_error_upper_bound" : 0,
            "sum_other_doc_count" : 0,
            "buckets" : [
              {
                "key" : "qingxin",
                "doc_count" : 1,
                "averge_price" : {
                  "value" : 40.0
                }
              }
            ]
          }
        }
      ]
    }
  }
}

https://www.cnblogs.com/haixiang/p/12040272.html