ElasticSearch 聚合统计_elasticsearch 聚合平均数-优快云博客

本文链接：https://blog.youkuaiyun.com/zzti_erlie/article/details/135225411

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准备数据

PUT user
{
  "mappings": {
    "properties": {
      "age": {"type": "integer"},
      "email": {"type": "keyword"},
      "name": {"type": "keyword"},
      "address": {"type": "text", "analyzer": "ik_smart"}
    }
  }
}

POST user/_bulk
{"index": {"_id": 1}}
{"name": "张三", "age": 10, "email": "1.qq.com", "address": "北京朝阳"}
{"index": {"_id": 2}}
{"name": "李四", "age": 20, "email": "2.qq.com", "address": "北京西城"}
{"index": {"_id": 3}}
{"name": "王五", "age": 30, "email": "3.qq.com", "address": "北京东城"}
{"index": {"_id": 4}}
{"name": "赵六", "age": 40, "email": "4.qq.com", "address": "北京海淀"}

聚合统计

度量聚合：求字段的平均值，最小值，最大值，总和等
桶聚合：将文档分成不同的桶，桶的划分可以根据字段的值，范围，日期间隔
管道聚合：在桶聚合的结果上执行进一步计算

进行聚合的语法如下

{
  "aggs": {
    "<agg_name>": {
      "<agg_type>": {
        "field": "<field_name>"
      }
    }
  }
}

聚合也可以进行嵌套

{
  "aggs": {
    "<agg_name>": {
      "<agg_type>": {
        "field": "<field_name>"
      },
      "aggs": {
        "<agg_child_name>": {
          "<agg_type>": {
            "field": "<field_name>"
          }
        }
      }
    }
  }
}

度量聚合（Metrics aggregations）

平均值聚合

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {"avg_age": {"avg": {"field": "age"}}}
}

在 ElasticSearch 中进行聚合统计时，默认情况下会返回原始文档和聚合结果，如果只想获取聚合结果而不需要原始文档，可以通过设置 size 参数为 0 来实现

POST user/_search
{
  "size": 0,
  "query": {
    "match_all": {}
  },
  "aggs": {"avg_age": {"avg": {"field": "age"}}}
}

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最小值 / 最大值聚合

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {"max_age": {"max": {"field": "age"}}}
}

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {"min_age": {"min": {"field": "age"}}}
}

求和聚合

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {"sum_age": {"sum": {"field": "age"}}}
}

桶聚合（Bucket aggregations）

词条聚合（Terms aggregation）

按照某个字段的值进行聚合

POST user/_search
{
  "size": 0,
  "query": {
    "match_all": {}
  },
  "aggs": {"group_by_age": {"terms": {"field": "age"}}}
}

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范围聚合（Range aggregation）

按照某个字段的范围进行聚合，from提供区间下界（包括），to提供区间上界（不包括）

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {
    "age_ranges":{
      "range": {
        "field": "age",
        "ranges": [
          { "to": 10 },
          { "from": 10, "to": 20 },
          { "from": 20 }
        ]
      }
    }
  }
}

管道聚合（Pipeline aggregations）

平均桶聚合（Average bucket aggregation）

POST user/_search
{
  "size": 0,
  "query": {
    "match_all": {}
  },
  "aggs": {
    "age_ranges": {
      "range": {
        "field": "age",
        "ranges": [
          { "to": 10 }, { "from": 10, "to": 20 }, { "from": 20 }
        ]
      },
      "aggs": {
        "age_avg": {"avg": {"field": "age"}}
      }
    },
    "range_avg": {
      "avg_bucket": {"buckets_path": "age_ranges>age_avg"}
    }
  }
}

对年龄分组，并求分组后的平均值，然后对分组的平均值再求平均值

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求和桶聚集（Sum bucket aggregation）

POST user/_search
{
  "query": {
    "match_all": {}
  },
  "aggs": {
    "age_ranges": {
      "range": {
        "field": "age",
        "ranges": [
          { "to": 10 }, { "from": 10, "to": 20 }, { "from": 20 }
        ]
      },
      "aggs": {
        "age_sum": { "sum": {"field": "age"} }
      }
    },
    "range_sum": {
      "sum_bucket": { "buckets_path": "age_ranges>age_sum" }
    }
  }
}