聚合

准备数据

POST my-index/person/1
{
  "name":"小明",
  "age":28,
  "salary":10000
}

PUT my-index/person/2
{
  "name":"hadron",
  "age":19,
  "salary":5000
}

max：查询最大值 min查询最小值

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "max_age": {
      "max": {"field": "age"}
    }
  }
}

GET my-index/_search
{
  "size": 20,
  "aggs": {
    "min_salary": {
      "min": {
        "field": "salary"
      }
    }
  }
}

max_age、min_salary为聚合查询以后所显示的名字 aggs：aggregations聚合的意思

ave：平均值

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "avg_salary": {
      "avg": {"field": "salary"}
    }
  }
}

sum求和

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "sum_salary": {
      "sum": {"field": "salary"}
    }
  }
}

stats 显示所有的计算状态

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "stats_salary": {
      "stats": {"field": "salary"}
    }
  }
}

extended_stats 更全

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "stats_salary": {
      "extended_stats": {"field": "salary"}
    }
  }
}

cardinality基数统计，工资有几个等级

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "class_salary": {
      "cardinality": {"field": "salary"}
    }
  }
}

value_count：文档数量统计

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "doc_count": {
      "value_count": {"field": "salary"}
    }
  }
}

percentiles

GET my-index/_search
{
  "size": 0, 
  "aggs": {
    "persion_salary": {
      "percentiles": {"field": "salary"}
    }
  }
}