本文基于ES6.4版本,我也是出于学习阶段,对学习内容做个记录,如果文中有错误,请指出。
实验数据:
index:book
type:novel
mappings:


{"mappings": {"novel": {"dynamic": "false","properties": {"word_count": {"type": "integer"},"author": {"type": "keyword"},"title": {"type": "text"},"publish_date": {"format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis","type": "date"}}}} }
通过put创建索引,使用head可视化界面,数据如下:
Elasticsearch的查询分为:
1、子条件查询:查询特定字段的特定值
Query context
查询过程中,除了判断Document是否满足条件,还会计算出_score表示匹配程度,数值越大,证明匹配程度越高
1、查询全部:/book/novel/_search


"hits": {"total": 10,"max_score": 1.0,"hits": [{"_index": "book","_type": "novel","_id": "5","_score": 1.0,"_source": {"title": "永夜君王","word_count": "110000","publish_date": "2015-03-01","author": "烟雨江南"}},{"_index": "book","_type": "novel","_id": "8","_score": 1.0,"_source": {"title": "万古令","word_count": "110000","publish_date": "2015-03-01","author": "听奕"}},{"_index": "book","_type": "novel","_id": "9","_score": 1.0,"_source": {"title": "天帝传","word_count": "110000","publish_date": "2015-03-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "10","_score": 1.0,"_source": {"title": "剑来","word_count": "110000","publish_date": "2015-03-01","author": "烽火戏诸侯"}},{"_index": "book","_type": "novel","_id": "2","_score": 1.0,"_source": {"title": "完美世界","word_count": "130000","publish_date": "2017-03-01","author": "辰东"}},{"_index": "book","_type": "novel","_id": "4","_score": 1.0,"_source": {"title": "民国谍影","word_count": "110000","publish_date": "2019-03-01","author": "寻青藤"}},{"_index": "book","_type": "novel","_id": "6","_score": 1.0,"_source": {"title": "遮天","word_count": "110000","publish_date": "2015-03-01","author": "辰东"}},{"_index": "book","_type": "novel","_id": "1","_score": 1.0,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "7","_score": 1.0,"_source": {"title": "圣墟","word_count": "110000","publish_date": "2015-03-01","author": "辰东"}},{"_index": "book","_type": "novel","_id": "3","_score": 1.0,"_source": {"title": "星辰变","word_count": "100000","publish_date": "2018-03-01","author": "我吃西红柿"}}]}
2、查询id为1的数据:/book/novel/1


{"_index": "book","_type": "novel","_id": "1","_version": 1,"found": true,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"} }
3、只查询title和author字段:/1?_source=title,author


{"_index": "book","_type": "novel","_id": "1","_version": 1,"found": true,"_source": {"author": "飞天鱼","title": "万古神帝"} }
4、只是显示_source部分:/book/novel/1/_source


{"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼" }
5、筛选单字段查询:/book/novel/_search
{"query": {"match": {"author": "飞天鱼"}} }


"hits": {"total": 2,"max_score": 1.2039728,"hits": [{"_index": "book","_type": "novel","_id": "9","_score": 1.2039728,"_source": {"title": "天帝传","word_count": "110000","publish_date": "2015-03-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "1","_score": 0.6931472,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"}}]}
6、limit:我们查询到2条数据,如果我们只想得到第一条数据,可以使用from和size联合查询
{"query": {"match": {"author": "飞天鱼"}},"from": 0,"size": 1 }


"hits": {"total": 2,"max_score": 1.2039728,"hits": [{"_index": "book","_type": "novel","_id": "9","_score": 1.2039728,"_source": {"title": "天帝传","word_count": "110000","publish_date": "2015-03-01","author": "飞天鱼"}}]}
{"query": {"match": {"author": "辰东"}},"sort": [{"word_count": {"order": "desc"}} ] }


"hits": {"total": 3,"max_score": null,"hits": [{"_index": "book","_type": "novel","_id": "2","_score": null,"_source": {"title": "完美世界","word_count": "130000","publish_date": "2017-03-01","author": "辰东"},"sort": [130000]},{"_index": "book","_type": "novel","_id": "6","_score": null,"_source": {"title": "遮天","word_count": "110000","publish_date": "2015-03-01","author": "辰东"},"sort": [110000]},{"_index": "book","_type": "novel","_id": "7","_score": null,"_source": {"title": "圣墟","word_count": "110000","publish_date": "2015-03-01","author": "辰东"},"sort": [110000]}]}
8、其余匹配match_phrase:
query、match的方式本质上就是模糊查询,而且中文会自动分词到最大粒度,可以看到会查询到只要匹配任意一个字都是可以的
{"query": {"match": {"title": "万古神帝"}} }


"hits": {"total": 3,"max_score": 2.439878,"hits": [{"_index": "book","_type": "novel","_id": "1","_score": 2.439878,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "8","_score": 2.4079456,"_source": {"title": "万古令","word_count": "110000","publish_date": "2015-03-01","author": "听奕"}},{"_index": "book","_type": "novel","_id": "9","_score": 1.2039728,"_source": {"title": "天帝传","word_count": "110000","publish_date": "2015-03-01","author": "飞天鱼"}}]}
所以这里有了其余匹配match_phrase,结果只有完全包含"万古神帝"的title才可以被查询到
{"query": {"match_phrase": {"title": "万古神帝"}} }


"hits": {"total": 1,"max_score": 2.439878,"hits": [{"_index": "book","_type": "novel","_id": "1","_score": 2.439878,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"}}]}
9、多条件查询multi_match:查询title或者author包含"万古神帝"的数据
{"query": {"multi_match": {"query": "万古神天","fields": ["title","author"]}} }


"hits": {"total": 4,"max_score": 2.4079456,"hits": [{"_index": "book","_type": "novel","_id": "8","_score": 2.4079456,"_source": {"title": "万古令","word_count": "110000","publish_date": "2015-03-01","author": "听奕"}},{"_index": "book","_type": "novel","_id": "1","_score": 1.8299085,"_source": {"title": "万古神帝","word_count": "30000","publish_date": "2017-01-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "9","_score": 1.2039728,"_source": {"title": "天帝传","word_count": "110000","publish_date": "2015-03-01","author": "飞天鱼"}},{"_index": "book","_type": "novel","_id": "6","_score": 1.1727304,"_source": {"title": "遮天","word_count": "110000","publish_date": "2015-03-01","author": "辰东"}}]}
10、语法查询query_string:
{"query": {"query_string": {"query": "万古"}} }
这里和match没有区别,query可以使用AND和OR,match的filed也可以,注意这里一定是大写,小写就被当做搜索的内容了
{"query": {"query_string": {"query": "万古 OR 剑来"}} }
{"query": {"match": {"title": "万古 OR 剑来"}} }
指定fields:
{"query": {"query_string": {"query": "万古 OR 剑来 OR 辰东 ","fields": ["author","title"]}} }
11、精确匹配term:
title为text类型,author为keyword类型,实验发现查询title只有是单个字的时候才能匹配(精确匹配查不到数据),而author必须是精确匹配
例如:title不支持精确匹配,支持模糊查询(而且是单个字才可以,多个字照样查不到数据)
{"query": {"term": {"title": "剑来"}} }
如果只是查询一个字就可以
{"query": {"term": {"title": "来"}} }


"hits": {"total": 1,"max_score": 1.3940737,"hits": [{"_index": "book","_type": "novel","_id": "10","_score": 1.3940737,"_source": {"title": "剑来","word_count": "110000","publish_date": "2015-03-01","author": "烽火戏诸侯"}}]}
查询author字段:有三条数据
{"query": {"term": {"author": "辰东"}} }


"hits": [{"_index": "book","_type": "novel","_id": "7","_score": 0.6931472,"_source": {"title": "圣墟","word_count": "110000","publish_date": "2015-03-01","author": "辰东"}},{"_index": "book","_type": "novel","_id": "2","_score": 0.47000363,"_source": {"title": "完美世界","word_count": "130000","publish_date": "2017-03-01","author": "辰东"}},{"_index": "book","_type": "novel","_id": "6","_score": 0.47000363,"_source": {"title": "遮天","word_count": "110000","publish_date": "2015-03-01","author": "辰东"}}]}
author不知道模糊查询:下面结果为null
{"query": {"term": {"author": "东"}} }
12、范围查找range:包括integer和日期类型,日期支持now函数,也就是当前日期
{"query": {"range": {"word_count": {"gt": 110000,"lte": 130000}}} }


"hits": {"total": 1,"max_score": 1.0,"hits": [{"_index": "book","_type": "novel","_id": "2","_score": 1.0,"_source": {"title": "完美世界","word_count": "130000","publish_date": "2017-03-01","author": "辰东"}}]}
Filter context
查询过程中,只是判断Document是否满足条件,只有yes or no。用来做数据过滤,而且ES还会对结果进行缓存,效率相对query更高一点
{"query": {"bool": {"filter": {"term": {"word_count": 130000}}}} }


"hits": {"total": 1,"max_score": 0.0,"hits": [{"_index": "book","_type": "novel","_id": "2","_score": 0.0,"_source": {"title": "完美世界","word_count": "130000","publish_date": "2017-03-01","author": "辰东"}}]}
2、复合条件查询:组合子条件查询
1、固定分数查询:不支持match,支持filter
{"query": {"constant_score": {"filter": {"match": {"title": "天帝传"}}}} }{"query": {"constant_score": {"filter": {"match": {"title": "天帝传"}},"boost": 2}} }
2、bool查询:
should:就是or的关系
{"query": {"bool": {"should": [{"match": {"author": "辰东"}},{"match": {"title": "天帝传"}}]}} }
must:相当于and
{"query": {"bool": {"must": [{"match": {"author": "辰东"}},{"match": {"title": "天帝传"}}]}} }
must_not:相当于<>
{"query": {"bool": {"must_not": {"term": {"author": "辰东"}}}} }
bool查询也可以使用filter:
{"query": {"bool": {"must": [{"match": {"author": "辰东"}},{"match": {"title": "天帝传"}}],"filter": [{"term": {"word_count": 110000}} ]}} }
aggregations:
{"aggs": {"group_by_author": {"terms": {"field": "author"}}} }


"aggregations": {"group_by_author": {"doc_count_error_upper_bound": 0,"sum_other_doc_count": 0,"buckets": [{"key": "辰东","doc_count": 3},{"key": "飞天鱼","doc_count": 2},{"key": "听奕","doc_count": 1},{"key": "寻青藤","doc_count": 1},{"key": "我吃西红柿","doc_count": 1},{"key": "烟雨江南","doc_count": 1},{"key": "烽火戏诸侯","doc_count": 1}]}}
支持多聚合结果:
{"aggs": {"group_by_author": {"terms": {"field": "author"}},"group_by_word_count": {"terms": {"field": "word_count"}}} }
aggregations除了支持term,还有stats、min、max、avg等
{"aggs": {"group_by_author": {"stats": {"field": "word_count"}}} }
"aggregations": {"group_by_author": {"count": 10,"min": 30000.0,"max": 130000.0,"avg": 103000.0,"sum": 1030000.0}}
avg:
{"aggs": {"group_by_author": {"avg": {"field": "word_count"}}} }