Elasticsearch系列--queryfilteraggregations
Posted huigelaile
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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" ]
hits.total=2，但是只返回了第一条数据，from为从第几条开始，size我返回的条数
7、order by：
这里选择对word_count字段进行倒叙排序
"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"
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