1. 首页
  2. elasticsearch教程

18-十八、Elasticsearch 教程: 查询描述语言

Elasticsearch 使用基于 JSON 数据格式的查询来执行搜索

查询由两个子句组成:

1、叶子查询短语

这种短语包括 匹配 ( matching ) 、词 ( term ) 或范围 ( range ),用于在特定的字段中查找特定的值
2、复合查询短语

这种查询短语由 叶子查询短语 和其它复合查询短语组成,用于提取所需要的数据

Elasticsearch 支持数量庞大的各种不同类型的查询

这些查询以 query 开始,然后使用 JSON 对象包含条件和过滤器

本章接下来的内容将学习和介绍各种不同类型的查询

匹配所有的查询

这是最基本的查询,它会返回所有的内容,其中的每个对象的得分都是 1.0

这种查询的请求正文一般为


{ "query":{ "match_all":{} } }

例如下面的请求用于查询 user* 索引中的所有数据


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "match_all":{} } }

响应内容


{ "took": 21, "timed_out": false, "_shards": { "total": 10, "successful": 10, "skipped": 0, "failed": 0 }, "hits": { "total": 5, "max_score": 1, "hits": [ { "_index": "user", "_type": "user", "_id": "2", "_score": 1, "_source": { "nickname": "枫晚", "description": "停车坐爰枫林晚", "street": "苏州大学", "city": "Suzhou", "state": "Jiangsu", "zip": "215006", "location": [ 120.65426, 31.30797 ], "money": 10235, "tags": [ "Java", "Android" ], "vitality": "3.5" } }, { "_index": "user_admin", "_type": "user", "_id": "2", "_score": 1, "_source": { "nickname": "雅少", "description": "虚怀若谷", "street": "四川大学", "city": "Chengdu", "state": "Sichuan", "zip": "610044", "location": [ 104.094537, 30.640174 ], "money": 68023, "tags": [ "Python", "HTML" ], "vitality": "7.8" } }, { "_index": "user", "_type": "user", "_id": "1", "_score": 1, "_source": { "nickname": "question", "description": "问题少年也是少年", "street": "张江高科技园区", "city": "Shanghai", "state": "Shanghai", "zip": "201204", "location": [ 121.60632, 31.199305 ], "money": 13648, "tags": [ "VUE", "HTML" ], "vitality": "8.8" } }, { "_index": "user_admin", "_type": "user", "_id": "1", "_score": 1, "_source": { "nickname": "站长", "description": "搜云库技术团队 ,教程 ", "street": "东四十条", "city": "Beijing", "state": "Beijing", "zip": "100007", "location": [ 116.432727, 39.937732 ], "money": 5201814, "tags": [ "PHP", "Python" ], "vitality": "9.0" } }, { "_index": "user_admin", "_type": "user", "_id": "3", "_score": 1, "_source": { "nickname": "歌者", "description": "程序设计也是设计,研发新菜也是研发", "street": "五道口", "city": "Beijing", "state": "Beijing", "zip": "100083", "location": [ 116.346346, 39.999333 ], "money": 71128, "tags": [ "Java", "Scala" ], "vitality": "6.9" } } ] } }

全文检索查询

这些查询会搜索整个文本,如章节或新闻文章

这种查询会用到与指定的索引或文档相关联的分析器,由分析器对内容进行分析

接下来,我们就看看 Elasticsearch 支持哪些全文检索查询

匹配查询

这种查询将文本或短语与一个或多个字段的值进行匹配,返回匹配成功的文档

例如下面的查询请求用于查询所有城市为 pune 的学校


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "match" : { "city":"Chengdu" } } }

响应内容


{ "took" : 15, "timed_out" : false, "_shards" : { "total" : 10, "successful" : 10, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 1, "max_score" : 0.2876821, "hits" : [ { "_index" : "user_admin", "_type" : "user", "_id" : "2", "_score" : 0.2876821, "_source" : { "nickname" : "雅少", "description" : "虚怀若谷", "street" : "四川大学", "city" : "Chengdu", "state" : "Sichuan", "zip" : "610044", "location" : [ 104.094537, 30.640174 ], "money" : 68023, "tags" : [ "Python", "HTML" ], "vitality" : "7.8" } } ] } }

多字段匹配查询

这种查询会将文本或短语与多个字段进行匹配

例如下面的请求,将在 citystate 字段上查找匹配 shanghai 的内容


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "multi_match" : { "query": "shanghai", "fields": [ "city", "state" ] } } }

返回响应


{ "took" : 30, "timed_out" : false, "_shards" : { "total" : 10, "successful" : 10, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 1, "max_score" : 0.2876821, "hits" : [ { "_index" : "user", "_type" : "user", "_id" : "1", "_score" : 0.2876821, "_source" : { "nickname" : "question", "description" : "问题少年也是少年", "street" : "张江高科技园区", "city" : "Shanghai", "state" : "Shanghai", "zip" : "201204", "location" : [ 121.60632, 31.199305 ], "money" : 13648, "tags" : [ "VUE", "HTML" ], "vitality" : "8.8" } } ] } }

查询字符串查询

这种查询会使用 query_string 来指定要查询的关键字,然后用查询分析器来分析查询关键字

例如下面的查询请求将返回包含 的查询结果


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "query_string":{ "query":"语 枫" } } }

返回响应


{ "took" : 111, "timed_out" : false, "_shards" : { "total" : 10, "successful" : 10, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 2, "max_score" : 0.2876821, "hits" : [ { "_index" : "user", "_type" : "user", "_id" : "2", "_score" : 0.2876821, "_source" : { "nickname" : "枫晚", "description" : "停车坐爰枫林晚", "street" : "苏州大学", "city" : "Suzhou", "state" : "Jiangsu", "zip" : "215006", "location" : [ 120.65426, 31.30797 ], "money" : 10235, "tags" : [ "Java", "Android" ], "vitality" : "3.5" } }, { "_index" : "user_admin", "_type" : "user", "_id" : "1", "_score" : 0.2876821, "_source" : { "nickname" : "站长", "description" : "搜云库技术团队 ,教程 ", "street" : "东四十条", "city" : "Beijing", "state" : "Beijing", "zip" : "100007", "location" : [ 116.432727, 39.937732 ], "money" : 5201814, "tags" : [ "PHP", "Python" ], "vitality" : "9.0" } } ] } }

术语级别查询

这种查询主要用于查询结构化的数据,比如数字、日期和枚举 ( emuns )

例如下面的查询返回所有 zip100007 的数据


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "term":{"zip":"100007"} } }

响应内容


{ "took" : 23, "timed_out" : false, "_shards" : { "total" : 10, "successful" : 10, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 1, "max_score" : 0.2876821, "hits" : [ { "_index" : "user_admin", "_type" : "user", "_id" : "1", "_score" : 0.2876821, "_source" : { "nickname" : "站长", "description" : "搜云库技术团队 ,教程 ", "street" : "东四十条", "city" : "Beijing", "state" : "Beijing", "zip" : "100007", "location" : [ 116.432727, 39.937732 ], "money" : 5201814, "tags" : [ "PHP", "Python" ], "vitality" : "9.0" } } ] } }

范围查询

这种查询主要用于查询那些值处于某个范围区间的对象

为此,我们还需要使用下面的关键字

关键字 说明
gte 大于等于
gt 大于
lte 小于等于
lt 小于

例如下面的查询用于返回那些 vitality 在 5.5 以上的文档


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "range":{ "vitality":{ "gte":5.5 } } } }

响应内容


{ "took" : 71, "timed_out" : false, "_shards" : { "total" : 10, "successful" : 10, "skipped" : 0, "failed" : 0 }, "hits" : { "total" : 4, "max_score" : 1.0, "hits" : [ { "_index" : "user_admin", "_type" : "user", "_id" : "2", "_score" : 1.0, "_source" : { "nickname" : "雅少", "description" : "虚怀若谷", "street" : "四川大学", "city" : "Chengdu", "state" : "Sichuan", "zip" : "610044", "location" : [ 104.094537, 30.640174 ], "money" : 68023, "tags" : [ "Python", "HTML" ], "vitality" : "7.8" } }, { "_index" : "user", "_type" : "user", "_id" : "1", "_score" : 1.0, "_source" : { "nickname" : "question", "description" : "问题少年也是少年", "street" : "张江高科技园区", "city" : "Shanghai", "state" : "Shanghai", "zip" : "201204", "location" : [ 121.60632, 31.199305 ], "money" : 13648, "tags" : [ "VUE", "HTML" ], "vitality" : "8.8" } }, { "_index" : "user_admin", "_type" : "user", "_id" : "1", "_score" : 1.0, "_source" : { "nickname" : "站长", "description" : "搜云库技术团队 ,教程 ", "street" : "东四十条", "city" : "Beijing", "state" : "Beijing", "zip" : "100007", "location" : [ 116.432727, 39.937732 ], "money" : 5201814, "tags" : [ "PHP", "Python" ], "vitality" : "9.0" } }, { "_index" : "user_admin", "_type" : "user", "_id" : "3", "_score" : 1.0, "_source" : { "nickname" : "歌者", "description" : "程序设计也是设计,研发新菜也是研发", "street" : "五道口", "city" : "Beijing", "state" : "Beijing", "zip" : "100083", "location" : [ 116.346346, 39.999333 ], "money" : 71128, "tags" : [ "Java", "Scala" ], "vitality" : "6.9" } } ] } }

还存在一些其它类型的术语级别查询,我们就不一一介绍了,先罗列在此

查询 说明
存在查询 返回某个字段不为null的对象
缺失查询 与存在查询相反,这种查询用于搜索不存在某个字段或即使存在其值也为null的对象
通配符或正则查询 使用正则表达式来匹配某个字段的值是否符合某个模式的对象

类型查询

用于查询那些符合某个类型的文档

例如下面的查询请求用于查询符合 user 类型的文档


POST http://localhost:9200/user*/_search

请求正文


{ "query":{ "type" : { "value" : "user" } } }

响应内容

返回的响应一定是 user 索引索引中的全部 JSON 对象文档

复合查询

这种查询使用布尔运算符( 例如 andornot ) 运算符来组合不同的索引或函数调用返回的不同的查询的结果

例如下面的复合查询


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "filtered":{ "query":{ "match":{ "state":"UP" } }, "filter":{ "range":{ "rating":{ "gte":4.0 } } } } } }

响应正文


{ "took":16, "timed_out":false, "_shards":{"total":10, "successful":10, "failed":0}, "hits":{"total":0, "max_score":null, "hits":[]} }

连接查询

这种查询用于包含多个映射或文档的情况

有两种类型的连接查询

1、嵌套查询

这种查询一般用于处理嵌套映射的情况,我们会在下一章节详细介绍
2、has_childhas_parent 查询

这种查询用于检索文档的子文档或父文档,以找出匹配查询的对象

例如下面这个查询请求


POST http://localhost:9200/tutorials/_search

请求正文


{ "query": { "has_child" : { "type" : "article", "query" : { "match" : { "Text" : "This is article 1 of chapter 1" } } } } }

返回响应内容


{ "took":21, "timed_out":false, "_shards":{"total":5, "successful":5, "failed":0}, "hits":{ "total":1, "max_score":1.0, "hits":[{ "_index":"tutorials", "_type":"chapter", "_id":"1", "_score":1.0, "_source":{ "Text":"this is chapter one" } }] } }

地理信息查询

这种查询可以处理地理位置信息和地理点

一般用于找出学校或任何地点附近的任何其它地理对象

对于这种查询,我们需要使用地理点数据类型

例如下面的查询


POST http://localhost:9200/user*/_search?pretty

请求正文


{ "query":{ "bool": { "filter":{ "geo_distance":{ "distance":"100km", "location":[116.4448,39.943042] } } } } }

响应正文


{ "error" : { "root_cause" : [ { "type" : "query_shard_exception", "reason" : "field [location] is not a geo_point field", "index_uuid" : "VYLD0ybxRLeVB_KsJ8ZjDw", "index" : "user" }, { "type" : "query_shard_exception", "reason" : "field [location] is not a geo_point field", "index_uuid" : "_acBr-_YSCiaHImp1VObGg", "index" : "user_admin" } ], "type" : "search_phase_execution_exception", "reason" : "all shards failed", "phase" : "query", "grouped" : true, "failed_shards" : [ { "shard" : 0, "index" : "user", "node" : "4zwAMlTzRCaioBeOE9PaNw", "reason" : { "type" : "query_shard_exception", "reason" : "field [location] is not a geo_point field", "index_uuid" : "VYLD0ybxRLeVB_KsJ8ZjDw", "index" : "user" } }, { "shard" : 0, "index" : "user_admin", "node" : "4zwAMlTzRCaioBeOE9PaNw", "reason" : { "type" : "query_shard_exception", "reason" : "field [location] is not a geo_point field", "index_uuid" : "_acBr-_YSCiaHImp1VObGg", "index" : "user_admin" } } ] }, "status" : 400 }

如果你在运行上面的范例时抛出了异常,那么可以运行下面的请求为索引添加映射


{ "mappings":{ "user":{ "properties":{ "location":{ "type":"geo_point" } } } } }

希望读者能够给小编留言,也可以点击[此处扫下面二维码关注微信公众号](https://www.ycbbs.vip/?p=28 "此处扫下面二维码关注微信公众号")

JS中文网,Javascriptc中文网是中国领先的新一代开发者社区和专业的技术媒体,一个帮助开发者成长的社区,是给开发者用的 Hacker News,技术文章由为你筛选出最优质的干货,其中包括:Android、iOS、前端、后端等方面的内容。目前已经覆盖和服务了超过 300 万开发者,你每天都可以在这里找到技术世界的头条内容。

本文著作权归作者所有,如若转载,请注明出处

转载请注明:文章转载自「 Java极客技术学习 」https://www.javajike.com

标题:18-十八、Elasticsearch 教程: 查询描述语言

链接:https://www.javajike.com/article/1261.html

« 19-十九、Elasticsearch 教程: 映射 ( Mapping )
17-十七、Elasticsearch 教程: 集群管理 API»

相关推荐

QR code