Elasticsearch第12节 聚合查询

一、聚合查询

//
#聚合查询 : sum
#  "size": 0  去掉明细列表，只保留求和结果
GET /lib4/_search
{
  "size": 0,  
  "aggs": {
    "self_define_name_for_result": {
      "sum": {"field":"price"}
    }
  }
}

#最小值：min
GET /lib4/_search
{
  "size": 0, 
  "aggs": {
    "price_min": {
      "min": {"field":"price"}
    }
  }
}
#最大值：max
GET /lib4/_search
{
  "size": 0, 
  "aggs": {
    "price_max": {
      "max": {"field":"price"}
    }
  }
}

#平均值：avg
GET /lib4/_search
{
  "size": 0, 
  "aggs": {
    "price_avg": {
      "avg": {"field":"price"}
    }
  }
}

#基数：cardinality (互不相同的值的个数)
#select count(distinct column) from talbe_name
GET /lib4/_search
{
  "size": 0, 
  "aggs": {
    "price_cardinality": {
      "cardinality": {"field":"price"}
    }
  }
}



#分组：terms 相当于group by 
# 数字类型OK，text类型的不行
GET /lib4/_search
{
  "size": 0, 
  "aggs": {
    "price_of_group": {
      "terms": {"field":"price"}
    }
  }
}
#结果（部分数据）：
  "aggregations" : {
    "price_of_group" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : 25,
          "doc_count" : 1
        },
        {
          "key" : 30,
          "doc_count" : 1
        }
         ......      ]
    }
  }


#兴趣中包含xi huan字样的用户按年龄分组求年龄的平均值
# 并对分组年龄的平均值按降序排列
GET /myindex/_search
{
  "size": 0, 
  "query": {
    "match": {
      "intrest": "xi huan"
    }
  },
  "aggs": {
    "post_date_group": {
      "terms": {
        "field": "age",
        "order": {
          "age_of_avg": "desc"
        }
      },
      "aggs": {
        "age_of_avg": {
          "avg": {
            "field": "age"
          }
        }
      }
    }
  }
}

二、复合查询

GET /myindex/_search
{
  "query":{
    "bool":{
      "must": [
        {"match":{"intrest": "xi huan"}}
      ],
      "must_not": [
        {"match": {"intrest": "football"}}
      ],
      "should": [
        {"match": {"content": "t"}},
        {"range": {"age": {"gte": 10,"lte": 30}}}
      ]
    }
  }
}



GET /myindex/_search
{
  "query":{
    "bool":{
      "must": [
        {"match":{"intrest": "xi huan"}}
      ],
      "must_not": [
        {"match": {"intrest": "football"}}
      ],
      "should": [
        {"match": {"content": "t"}}
      ],
      "filter": {
        "range": {"age": {"gte": 10,"lte": 30}}
      }
    }
  }
}

三、constant_score

//
# constant_score 
# 它将一个不变的常量评分应用于所有匹配的文档，它被经常用于
# 你只需要一个filter（例如评分查询）而没有其它查询的情况
# term被放置到了constant_score中，转成不评分的filter，
# 这种方式可以用来取代只有filter语句的bool查询
GET /myindex/_search
{
  "query": {
    "constant_score": {
      "filter": {"term": {
        "id": "120"
      }},
      "boost": 1.2
    }
  }
}