Elasticsearch系统学习(四)-简单查询及聚合函数
一、ES简单查询
查询主要有如下几种:
1、query string search
2、query DSL
3、query filter
4、full-text search
5、phrase search
6、highlight search
1.1、query string search
适用于临时的在命令行使用一些工具,比如curl,快速的发出请求,来检索想要的信息;但是如果查询请求很复杂,是很难去构建的。在生产环境中,几乎很少使用query string search
搜索全部商品:GET /ecommerce/product/_search
GET /ecommerce/product/_search { "took": 3, #耗费了几毫秒 "timed_out": false, #是否超时,这里是没有 "_shards": { #数据拆成了5个分片,所以对于搜索请求,会打到所有的primary shard(或者是它的某个replica shard也可以) "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, #查询结果的数量,4个document "max_score": 1, #score的含义,就是document对于一个search的相关度的匹配分数,越相关,就越匹配,分数也高 "hits": [ #包含了匹配搜索的document的详细数据 { "_index": "ecommerce", "_type": "product", "_id": "1_update", "_score": 1, "_source": { "doc": { "name": "jiaqiangban gaolujie yaogao" } } }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 1, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 1, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 1, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } } ] } }
搜索商品名称中包含yagao的商品,而且按照售价降序序:GET /ecommerce/product/_searchq=name:yagao&sort=price:desc
GET /ecommerce/product/_search?q=name:yagao&sort=price:desc { "took": 11, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": null, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": null, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] }, "sort": [ 40 ] }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": null, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] }, "sort": [ 30 ] }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": null, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] }, "sort": [ 25 ] } ] } }
1.2、query DSL
DSL:Domain Specified Language,特定领域的语言
http request body:请求体,可以用json的格式来构建查询语法,比较方便,可以构建各种复杂的语法,比query string search肯定强大多了
更加适合生产环境的使用,可以构建复杂的查询
1)查询所有的商品
GET /ecommerce/product/_search { "query": {"match_all": {}} #使用match_all } { "took": 4, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": 1, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 1, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 1, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 1, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } } ] } }
2)查询名称包含yagao的商品,同时按照价格降序排序
GET /ecommerce/product/_search { "query": { "match": { "name": "yagao" } }, "sort": [ {"price": "desc"} ] } { "took": 7, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": null, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": null, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] }, "sort": [ 40 ] }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": null, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] }, "sort": [ 30 ] }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": null, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] }, "sort": [ 25 ] } ] } }
3)分页查询商品
总共3条商品,假设每页就显示1条商品,现在显示第2页,所以就查出来第2个商品
GET /ecommerce/product/_search { "query": {"match_all": {}}, "from": 1, #从第几个开始查询 "size": 1 #查询几个 } { "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": 1, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 1, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } } ] } }
4)指定要查询出来商品的名称和价格
GET /ecommerce/product/_search { "query": {"match_all": {}}, "_source": ["name","price"] } { "took": 13, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 3, "max_score": 1, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 1, "_source": { "price": 25, "name": "jiajieshi yagao" } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 1, "_source": { "price": 30, "name": "gaolujie yagao" } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 1, "_source": { "price": 40, "name": "zhonghua yagao" } } ] } }
1.3、query filter
搜索商品名称包含yagao,而且售价大于25元的商品
GET /ecommerce/product/_search { "query": { "bool": { "must": { "match": { "name":"yagao" } }, "filter": { "range": { "price": {"gt": 25} } } } } } { "took": 7, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 2, "max_score": 0.25811607, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 0.25811607, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 0.25811607, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } } ] } }
1.4、full-text search(全文检索)
全文检索图解:
新增条数据:
put /ecommerce/product/4 { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": ["meibai"] }
查看所有数据:
GET /ecommerce/product/_search { "query": { "match_all": {} } }
全文检索:查询producer字段带有”yagao producer”的商品
GET /ecommerce/product/_search { "query": { "match": { "producer": "yagao producer" } } } #原理说明: producer这个字段,会先被拆解,建立倒排索引,yagao producer ---> yagao和producer special 4 yagao 4 producer 1,2,3,4 gaolujie 1 zhognhua 3 jiajieshi 2 { "took": 14, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0.70293105, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "4", "_score": 0.70293105, #相关度得分最高 "_source": { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": [ "meibai" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 0.25811607, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 0.25811607, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 0.1805489, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] } } ] } }
1.5、phrase search(短语搜索)
跟全文检索相对应,相反,全文检索会将输入的搜索串拆解开来,去倒排索引里面去一一匹配,只要能匹配上任意一个拆解后的单词,就可以作为结果返回
phrase search,要求输入的搜索串,必须在指定的字段文本中,完全包含一模一样的,才可以算匹配,才能作为结果返回
GET /ecommerce/product/_search { "query": { "match_phrase": { "producer": "yagao producer" } } } { "took": 18, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 1, "max_score": 0.70293105, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "4", "_score": 0.70293105, "_source": { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": [ "meibai" ] } } ] } }
1.6、highlight search(高亮搜索结果)
GET /ecommerce/product/_search { "query": { "match": { "producer":"producer" } }, "highlight": { "fields": { "producer": {} } } } { "took": 37, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0.25811607, "hits": [ { "_index": "ecommerce", "_type": "product", "_id": "1", "_score": 0.25811607, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] }, "highlight": { "producer": [ "gaolujie <em>producer</em>" #高亮显示<em>标签 ] } }, { "_index": "ecommerce", "_type": "product", "_id": "3", "_score": 0.25811607, "_source": { "name": "zhonghua yagao", "desc": "caoben zhiwu", "price": 40, "producer": "zhonghua producer", "tags": [ "qingxin" ] }, "highlight": { "producer": [ "zhonghua <em>producer</em>" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "2", "_score": 0.1805489, "_source": { "name": "jiajieshi yagao", "desc": "youxiao fangzhu", "price": 25, "producer": "jiajieshi producer", "tags": [ "fangzhu" ] }, "highlight": { "producer": [ "jiajieshi <em>producer</em>" ] } }, { "_index": "ecommerce", "_type": "product", "_id": "4", "_score": 0.14638957, "_source": { "name": "special yagao", "desc": "special meibai", "price": 50, "producer": "special yagao producer", "tags": [ "meibai" ] }, "highlight": { "producer": [ "special yagao <em>producer</em>" ] } } ] } }
二、聚合函数
聚合函数有:avg,groupby,sort等
1)计算每个tag下的商品数量
GET /ecommerce/product/_search { "aggs": { "group_by_tags": { #通过标签进行分组,名称可以自己定义 "terms": { "field": "tags" } } } } #报错 "Fielddata is disabled on text fields by default. Set fielddata=true on [tags] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory." #解决方法:将文本field的fielddata属性设置为true PUT /ecommerce/_mapping/product { "properties": { "tags": { "type": "text", "fielddata": true } } } #再次查询 GET /ecommerce/product/_search { "size": 0, #不显示原始数据 "aggs": { "all_tags": { "terms": { "field": "tags" } } } } { "took": 20, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "group_by_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "fangzhu", "doc_count": 2 }, { "key": "meibai", "doc_count": 2 }, { "key": "qingxin", "doc_count": 1 } ] } } }
2)对名称中包含yagao的商品,计算每个tag下的商品数量
GET /ecommerce/product/_search { "size": 0, "query": { "match": { "name": "yagao" } }, "aggs": { "all_tags": { "terms": { "field": "tags" } } } } { "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "all_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "fangzhu", "doc_count": 2 }, { "key": "meibai", "doc_count": 2 }, { "key": "qingxin", "doc_count": 1 } ] } } }
3)先分组,再算每组的平均值,计算每个tag下的商品的平均价格
GET /ecommerce/product/_search { "size": 0, "aggs": { "group_by_tags": { "terms": { "field": "tags" }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } } } { "took": 21, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "group_by_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "fangzhu", "doc_count": 2, "avg_price": { "value": 27.5 } }, { "key": "meibai", "doc_count": 2, "avg_price": { "value": 40 } }, { "key": "qingxin", "doc_count": 1, "avg_price": { "value": 40 } } ] } } }
4)计算每个tag下的商品的平均价格,并且按照平均价格降序排序
GET /ecommerce/product/_search { "size": 0, "aggs": { "all_tags": { "terms": { "field": "tags", "order": { "avg_price": "desc" } }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } } } { "took": 10, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "all_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "meibai", "doc_count": 2, "avg_price": { "value": 40 } }, { "key": "qingxin", "doc_count": 1, "avg_price": { "value": 40 } }, { "key": "fangzhu", "doc_count": 2, "avg_price": { "value": 27.5 } } ] } } }
5)按照指定的价格范围区间进行分组,然后在每组内再按照tag进行分组,最后再计算每组的平均价格
GET /ecommerce/product/_search { "size": 0, "aggs": { "group_by_price": { "range": { "field": "price", "ranges": [ { "from": 0, "to": 20 }, { "from": 20, "to": 40 }, { "from": 40, "to": 50 } ] }, "aggs": { "group_by_tags": { "terms": { "field": "tags" }, "aggs": { "avg_price": { "avg": { "field": "price" } } } } } } } } { "took": 22, "timed_out": false, "_shards": { "total": 5, "successful": 5, "failed": 0 }, "hits": { "total": 4, "max_score": 0, "hits": [] }, "aggregations": { "group_by_price": { "buckets": [ { "key": "0.0-20.0", "from": 0, "to": 20, "doc_count": 0, "group_by_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [] } }, { "key": "20.0-40.0", "from": 20, "to": 40, "doc_count": 2, "group_by_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "fangzhu", "doc_count": 2, "avg_price": { "value": 27.5 } }, { "key": "meibai", "doc_count": 1, "avg_price": { "value": 30 } } ] } }, { "key": "40.0-50.0", "from": 40, "to": 50, "doc_count": 1, "group_by_tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "qingxin", "doc_count": 1, "avg_price": { "value": 40 } } ] } } ] } } }
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