聚合分组

select * from table group by title.keyword

{"size": 0,"aggs": {"group_name": {"terms": {"field": "title.keyword"}}}
}

解释：
size:0 表示只展示聚合结果，不展示原始数据
aggs：表示聚合的操作符
group_name：给聚合操作取名
terms:根据字段的值进行分组
field:根据指定的字段值进行分组

求和

按照title分组求和
select sum(price) from table group by title.

{"size": 0,"aggs": {"group_name": {"terms": {"field": "title.keyword"},"aggs":{"sum_price":{"sum":{"field":"price"}}}}}
}

平均值

select avg(price) from table group by title.

{"size": 0,"aggs": {"group_name": {"terms": {"field": "title.keyword"},"aggs":{"avg_price":{"avg":{"field":"price"}}}}}
}

分析每种颜色下每种品牌的平均价格

{"size": 0,"aggs": {"group_name": {"terms": {"field": "color.keyword"},"aggs": {"group_by_brand": {"terms": {"field": "brand.keyword"},"aggs": {"avg_price_by_color": {"avg": {"field": "price"}}}}}}}
}

更多的metric学习

{"size": 0,"aggs": {"group_name": {"terms": {"field": "color.keyword"},"aggs": {"avg_price": {"avg": {"field": "price"}},"sum_price": {"sum": {"field": "price"}},"max_price": {"max": {"field": "price"}},"min_max": {"min": {"field": "price"}}}}}
}

输出：

  "took": 66,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": null,"hits": []},"aggregations": {"group_name": {"doc_count_error_upper_bound": 0,"sum_other_doc_count": 0,"buckets": [{"key": "white","doc_count": 2,"max_price": {"value": 5500},"min_max": {"value": 4500},"avg_price": {"value": 5000},"sum_price": {"value": 10000}},{"key": "blue","doc_count": 1,"max_price": {"value": 4000},"min_max": {"value": 4000},"avg_price": {"value": 4000},"sum_price": {"value": 4000}}]}}
}

一般来说，90%的常见的数据分析的操作，metric，无非就是count，avg，max，min，sum

Cardinality(唯一值)

cardinality 即去重计算，类似sql中 count（distinct），先去重再求和，计算指定field值的种类数。

{"size": 0,"aggs": {"cartinality_gender": {"cardinality": {"field": "city.keyword"}}}
}

输出

{"took": 2,"timed_out": false,"_shards": {"total": 5,"successful": 5,"skipped": 0,"failed": 0},"hits": {"total": 15,"max_score": 0,"hits": []},"aggregations": {"cartinality_gender": {"value": 15}}
}```## stats 一个聚合，输出多值
```java
{"size": 0,"aggs": {"stats_price": {"stats": {"field": "price"}}}
}

{"took": 3,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": null,"hits": []},"aggregations": {"stats_price": {"count": 3,"min": 4000,"max": 5500,"avg": 4666.666666666667,"sum": 14000}}
}

查询+聚合分析

{"query":{"match":{"title":"神州"}},"aggs":{"sum_price":{"sum":{"field":"price"}}}
}

输出

  "took": 54,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 2,"relation": "eq"},"max_score": 0.9983525,"hits": [{"_index": "aggs_index","_type": "_doc","_id": "5","_score": 0.9983525,"_source": {"brand": "huashuo","color": "white","price": 5500,"title": "神州"}},{"_index": "aggs_index","_type": "_doc","_id": "6","_score": 0.8416345,"_source": {"brand": "dell","color": "white","price": 4500,"title": "神州dell"}}]},"aggregations": {"sum_price": {"value": 10000}}
}

查询聚合+全局聚合 深入聚合数据分析_global bucket：单个品牌与所有品牌销量对比

global：就是global bucket，就是将所有数据纳入聚合的scope，而不管之前的query

{"query": {"match": {"title": "神州"}},"aggs": {"sum_price": {"sum": {"field": "price"}},"all": {"global": {},"aggs": {"all_sum_price": {"sum": {"field": "price"}}}}}
}

输出

{"query": {"match": {"title": "神州"}},"aggs": {"sum_price": {"sum": {"field": "price"}},"all": {"global": {},"aggs": {"all_sum_price": {"sum": {"field": "price"}}}}}
}

过滤+聚合：统计价格大于1200的电视平均价格

{"size": 0,"query": {"constant_score": {"filter": {"range": {"price": {"gte": 1200}}}}},"aggs": {"avg_price": {"avg": {"field": "price"}}}
}

统计最近一个月的平均价格

{"size": 0,"query": {"term": {"brand": {"value": "长虹"}}},"aggs": {"recent_150d": {"filter": {"range": {"sold_date": {"gte": "now-150d"}}},"aggs": {"recent_150d_avg_price": {"avg": {"field": "price"}}}},"recent_140d": {"filter": {"range": {"sold_date": {"gte": "now-140d"}}},"aggs": {"recent_140d_avg_price": {"avg": {"field": "price"}}}},"recent_130d": {"filter": {"range": {"sold_date": {"gte": "now-130d"}}},"aggs": {"recent_130d_avg_price": {"avg": {"field": "price"}}}}}
}

按照每种品牌的平均价格排序

{"size": 0,"aggs": {"group_by_color": {"terms": {"field": "brand.keyword","order":{"avg_price":"desc"}},"aggs": {"avg_price": {"avg": {"field": "price"}}}}}
}