您的位置:首页 > 健康 > 美食 > 佛山市网站建设分站哪家好_企业管理体系包含哪些内容_百度一下你就知道下载安装_上海专业做网站

佛山市网站建设分站哪家好_企业管理体系包含哪些内容_百度一下你就知道下载安装_上海专业做网站

2025/4/30 2:24:01 来源:https://blog.csdn.net/qq_54088234/article/details/147470690  浏览:    关键词:佛山市网站建设分站哪家好_企业管理体系包含哪些内容_百度一下你就知道下载安装_上海专业做网站
佛山市网站建设分站哪家好_企业管理体系包含哪些内容_百度一下你就知道下载安装_上海专业做网站

Elasticsearch 入门

前言

  • 官方地址:Elastic — 搜索 AI 公司 | Elastic

  • ES 下载地址:Past Releases of Elastic Stack Software | Elastic

  • 文档:什么是 Elasticsearch?|Elasticsearch 指南

简介

Elasticsearch 是一个分布式、RESTful 风格的搜索和数据分析引擎,能够解决不断涌现出的各种用例。作为 Elastic Stck 的核心,它集中存储您的数据,帮助您发现意料之中以及意料之外的情况。

The Elastic Stack,包括 Elasticsearch、Kibana、Beats 和 Logstash(也称为ELK Stack)。
能够安全可靠地获取任何来源、任何格式的数据,然后实时地对数据进行搜索、分析和可视化。

Elaticsearch,简称为 ES,ES 是一个开源的高扩展的分布式全文搜索引擎,是整个 Elastic Sack 技术栈的核心。它可以近乎实时的存储、检索数据;本身扩展性很好,可以扩展到上百台服务器,处理 PB 级别的数据。

全文搜索引擎

Google,百度类的网站搜索,它们都是根据网页中的关键字生成索引,我们在搜索的时候输入关键字,它们会将该关键字即索引匹配到的所有网页返回;还有常见的项目中应用日志的搜索等等。对于这些非结构化的数据文本,关系型数据库搜索不是能很好的支持。

一般传统数据库,全文检索都实现的很鸡肋,因为一般也没人用数据库存文本字段。进行全文检索需要扫描整个表,如果数据量大的话即使对 SQL 的语法优化,也收效甚微。建立了索引,但是维护起来也很麻烦,对于 insert 和 update 操作都会重新构建索引。

基于以上原因可以分析得出,在一些生产环境中,使用常规的搜索方式,性能是非常差的:

  • 搜索的数据对象是大量的非结构化的文本数据。
  • 文件记录量达到数十万或数百万个甚至更多。
  • 支持大量基于交互式文本的查询。
  • 需求非常灵活的全文搜索查询。
  • 对高度相关的搜索结果的有特殊需求,但是没有可用的关系数据库可以满足。
  • 对不同记录类型、非文本数据操作或安全事务处理的需求相对较少的情况。

为了解决结构化数据搜索和非结构化数据搜索性能问题,我们就需要专业,健壮,强大的全
文搜索引擎

这里说到的全文搜索引擎指的是目前广泛应用的主流搜索引擎。

它的工作原理是计算机索引程序通过扫描文章中的每一个词,对每一个词建立一个索引,指明该词在文章中出现的次数和位置,当用户查询时,检索程序就根据事先建立的索引进行查找,并将查找的结果反馈给用户的检索方式。

这个过程类似于通过字典中的检索字表查字的过程。

环境准备

Windows 版

Windows 版的 Elasticsearch 压缩包,解压即安装完毕,解压后的 Elasticsearch 的目录结构如下 :

  • 解压后,进入 bin 文件目录,点击 elasticsearch.bat 文件启动 ES 服务。
目录含义
bin可执行脚本目录
config配置目录
jdk内置 JDK 目录
lib类库
logs日志目录
modules模块目录
plugins插件目录

注意:

  • 9300 端口为 Elasticsearch 集群间组件的通信端口,
  • 9200 端口为浏览器访问的 http 协议 RESTful 端口。

打开浏览器,输入地址:http://localhost:9200,测试返回结果,返回结果如下:

  • 正常有返回结果即可
{"name": "CHENMENG","cluster_name": "elasticsearch","cluster_uuid": "kzJynYXKQge03U7WpEu8fg","version": {"number": "7.8.0","build_flavor": "default","build_type": "zip","build_hash": "757314695644ea9a1dc2fecd26d1a43856725e65","build_date": "2020-06-14T19:35:50.234439Z","build_snapshot": false,"lucene_version": "8.5.1","minimum_wire_compatibility_version": "6.8.0","minimum_index_compatibility_version": "6.0.0-beta1"},"tagline": "You Know, for Search"
}

倒排索引

正排索引(传统)

idcontent
1001my name is zhang san
1002my name is li si

倒排索引

keywordid
name1001,1002
zhang1001

Elasticsearch vs MySQL

Elasticsearch 是面向文档型数据库,一条数据在这里就是一个文档。

为了方便大家理解,我们将 Elasticsearch 里存储文档数据和关系型数据库 MySQL 存储数据的概念进行一个类比:

ElasticsearchMySQL说明
Cluster多个数据库实例整个 Elasticsearch 集群(多个节点)
Index✅ 更像 Table一个索引相当于一个“表”
Type(已废弃表(Table)旧版本中的 Type 类似于 MySQL 中的表,但 7.x+ 已废弃
Document行(Row)存储的每一条数据
Field列(Column)每个文档中的属性
Mapping表结构(Schema)定义字段类型和结构
Shard分片机制类似分库分表中的分片概念
Replica主从复制高可用副本机制

DSL 语法

  • json 格式,好理解,和 http 请求最兼容,应用最广
  • 官方文档:Query DSL | Elasticsearch Guide | Elastic

HTTP 操作

http 调试工具准备,例如:postman、apifox、apipost…

curl 也可

1、索引(表)

官方文档:Index APIs | Elasticsearch Guide | Elastic

创建 PUT

对比关系型数据库,创建【索引】就等同于创建【表】。

  • 但在使用上,Elasticsearch 的 Index 更强大、更灵活,比如它是分布式的,可以自带分片、复制、副本等能力,MySQL 表通常没有这些。

向 ES 服务器发 PUT 请求:http://127.0.0.1:9200/shopping

  • 请求后,服务器返回响应:
{"acknowledged": true,"shards_acknowledged": true,"index": "shopping"
}
  • 如果重复发 PUT 请求:http://127.0.0.1:9200/shopping 添加索引,会返回错误信息:
{"error": {"root_cause": [{"type": "resource_already_exists_exception","reason": "index [shopping/Z3ALzZdnQzGEJNoNSEGlvw] already exists","index_uuid": "Z3ALzZdnQzGEJNoNSEGlvw","index": "shopping"}],"type": "resource_already_exists_exception","reason": "index [shopping/Z3ALzZdnQzGEJNoNSEGlvw] already exists","index_uuid": "Z3ALzZdnQzGEJNoNSEGlvw","index": "shopping"},"status": 400
}
查询 GET

查看所有索引

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/_cat/indices?v

  • 这里请求路径中的 _cat 表示查看的意思,indices 表示索引,
  • 所以整体含义就是查看当前 ES 服务器中的所有索引,就好像 MySQL 中的 show tables 的感觉,
  • 服务器响应结果如下:
health status index    uuid                   pri rep docs.count docs.deleted store.size pri.store.size
yellow open   shopping Z3ALzZdnQzGEJNoNSEGlvw   1   1          0            0       208b           208b

响应结果说明:

表头含义
health当前服务器健康状态:green(集群完整)、yellow(单点正常/集群不完整)、red(单点不正常)
status索引打开、关闭状态
index索引名
uuid索引统一编号
pri主分片数量
rep副本数量
docs.count可用文档数量
docs.deleted文档删除状态(逻辑删除)
store.size主分片和副本整体占空间大小
pri.store.size主分片占空间大小

查看单个索引

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping

  • url 中 shopping 代表 索引名称

返回结果如下:

{"shopping": {"aliases": {},"mappings": {},"settings": {"index": {"creation_date": "1744101764908","number_of_shards": "1","number_of_replicas": "1","uuid": "Z3ALzZdnQzGEJNoNSEGlvw","version": {"created": "7080099"},"provided_name": "shopping"}}}
}
删除 DELETE

向 ES 服务器发 DELETE 请求:http://127.0.0.1:9200/shopping

返回结果如下:

{"acknowledged": true
}

2、文档(行)

这里的文档可以类比为关系型数据库中的表数据,添加的数据格式为 JSON 格式。

创建 POST

向 ES 服务器发 POST 请求:http://127.0.0.1:9200/shopping/_doc,请求体 JSON 内容为:

{"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00
}

返回结果如下:

{"_index": "shopping", //索引"_type": "_doc", // 类型-文档"_id": "aemnFJYBLUeT2LeerGCL", // 唯一标识,可以类比为 MySQL 中的主键,随机生成"_version": 1, // 版本"result": "created", // 结果,这里的 create 表示创建成功"_shards": {"total": 2, // 分片 - 总数"successful": 1, // 分片 - 总数"failed": 0 // 分片 - 总数},"_seq_no": 0,"_primary_term": 1
}

⚠️注意:

  • 上面的数据创建后,由于没有指定数据唯一性标识(ID),默认情况下, ES 服务器会随机生成一个。

如果想要自定义唯一性标识,需要在创建时指定:http://127.0.0.1:9200/shopping/_doc/1,请求体 JSON 内容为:

{"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00
}

返回结果如下:

{"_index": "shopping","_type": "_doc","_id": "1","_version": 1,  // 自定义唯一标识"result": "created","_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 1,"_primary_term": 1
}
主键查询 GET
  • 查看文档时,需要指明文档的唯一性标识,类似于 MySQL 中数据的主键查询
  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_doc/1

返回结果如下:

{"_index": "shopping","_type": "_doc","_id": "1","_version": 1,"_seq_no": 1,"_primary_term": 1,"found": true,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}
}

查找不存在的内容

  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_doc/1001

返回结果如下:

{"_index": "shopping","_type": "_doc","_id": "1001","found": false
}
查询索引下所有数据 GET
  • 相当于查询某张表下的所有数据
  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search

返回结果如下:

{"took": 384,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 2,"relation": "eq"},"max_score": 1.0,"hits": [{"_index": "shopping","_type": "_doc","_id": "aemnFJYBLUeT2LeerGCL","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "1","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}}]}
}
修改 POST

全量修改

和新增文档一样,输入相同的 URL 地址请求,如果请求体变化,会将原有的数据内容覆盖

  • 向 ES 服务器发 POST 请求:http://127.0.0.1:9200/shopping/_doc/1

请求体 JSON 内容为:

{"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/hw.jpg","price": 4999.00
}

修改成功后,服务器响应结果:

{"_index": "shopping","_type": "_doc","_id": "1","_version": 2,"result": "updated", // updated 表示数据被更新"_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 4,"_primary_term": 1
}

再次进行主键查询,结果如下:

{"_index": "shopping","_type": "_doc","_id": "1","_version": 2,"_seq_no": 4,"_primary_term": 1,"found": true,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/hw.jpg","price": 4999.00}
}

可以看到,修改成功。

局部修改

修改数据时,也可以只修改某一给条数据的局部信息

向 ES 服务器发 POST 请求:http://127.0.0.1:9200/shopping/_update/1

请求体 JSON 内容为:

{"doc": {"title": "小米手机","category": "小米"}
}
删除 DELETE

删除一个文档不会立即从磁盘上移除,它只是被标记成已删除(逻辑删除)。

向 ES 服务器发 DELETE 请求:http://127.0.0.1:9200/shopping/_doc/1

返回结果:

{"_index": "shopping","_type": "_doc","_id": "1", // 对应删除标识"_version": 4,"result": "deleted", // 表示删除成功"_shards": {"total": 2,"successful": 1,"failed": 0},"_seq_no": 6,"_primary_term": 2
}

向 ES 服务器发 GET请求:http://127.0.0.1:9200/shopping/_doc/1,查看是否删除成功:

{"_index": "shopping","_type": "_doc","_id": "1","found": false
}

3、映射操作(表结构)

先创建一个索引:

  • 向 ES 服务器发 PUT 请求:http://127.0.0.1:9200/user
创建映射 PUT
  • 向 ES 服务器发 PUT 请求:http://127.0.0.1:9200/user/_mapping
  • 附带 JSON 体如下
{"properties": {"name": {"type": "text","index": true},"sex": {"type": "keyword", // 关键词类型,查询的时候不会分词"index": true},"tel": {"type": "keyword","index": false // 字段不会被索引,不能用来搜索}}
}

映射数据说明

  • 字段名:任意填写,下面指定许多属性,例如:title、subtitle、images、price
  • type:类型,Elasticsearch 中支持的数据类型非常丰富,说几个关键的:
    • String 类型,又分两种:
      • text:可分词
      • keyword:不可分词,数据会作为完整字段进行匹配
    • Numerical:数值类型,分两类
      • 基本数据类型:longintegershortbytedoublefloathalf_float
      • 浮点数的高精度类型:scaled_float
    • Date:日期类型
    • Array:数组类型
    • Object:对象
  • index:是否索引,默认为 true,也就是说你不进行任何配置,所有字段都会被索引
    • true:字段会被索引,则可以用来进行搜索
    • false:字段不会被索引,不能用来搜索
  • store:是否将数据进行独立存储,默认为 false
    • 原始的文本会存储在 source 里面,默认情况下其他提取出来的字段都不是独立存储
      的,是从 source 里面提取出来的
    • 当然你也可以独立的存储某个字段,只要设置 "store":true 即可,获取独立存储的字段要比从 _source 中解析快得多,但是也会占用更多的空间,所以要根据实际业务需求来设置
  • analyzer:分词器,这里的 ik_max_word 即使用 ik 分词器
索引映射关联 PUT
  • 创建索引(表)时并创建映射(表结构)
  • 向 ES 服务器发 PUT 请求:http://127.0.0.1:9200/student
  • 附带 JSON 体如下
{"mappings": {"properties": {"name": {"type": "text"},"sex": {"type": "keyword"},"tel": {"type": "long","index": false}}}
}
查询映射 GET
  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/user/_mapping

4、复杂查询

确保索引下有数据

  • 先向索引(表)中新增多条测试数据

  • 然后查询所有数据,向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search

{"took": 661,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": 1.0,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}},{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": 1.0,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/xm.jpg","price": 5999.00}}]}
}
URL 带参查询

查找 category 为小米的文档

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search?q=category:小米,返回结果如下:

  • 可以看出来,会自动进行分词查询,即会查出 category 包含 的所有数据
{"took": 9,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 2,"relation": "eq"},"max_score": 2.5700645,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 2.5700645,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0296195,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}}]}
}
请求体带参查询

URL 带参数形式查询,这很容易让不善者心怀恶意,或者参数值出现中文会出现乱码情况。

为了避免这些情况,我们可用使用带 JSON 请求体请求进行查询。

接下带 JSON 请求体,还是查找 category 为小米的文档

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"match": {"category": "小米"}}
}

返回结果如下:

{"took": 790,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 2,"relation": "eq"},"max_score": 2.5700645,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 2.5700645,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0296195,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}}]}
}
查询所有文档(请求体)

查找所有文档内容,也可以这样,

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

  • 不带也是同样的效果
{"query": {"match_all": {}}
}
查询指定字段

如果你想查询指定字段

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

  • 比如,只查询 title 字段
{"query": {"match_all": {}},"_source": ["title"]
}

返回结果如下:

{"took": 53,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": 1.0,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.0,"_source": {"title": "小米手机"}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0,"_source": {"title": "红米手机"}},{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": 1.0,"_source": {"title": "华为手机"}}]}
}
分页查询
  • from:当前页的起始索引,默认从 0 开始。from = (pageNum - 1) * size
  • size:每页显示多少条

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"match_all": {}},"from": 0,"size": 2
}

返回结果如下:

{"took": 113,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": 1.0,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}}]}
}
排序查询
  • 根据价格进行降序查询

  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"match_all": {}},"sort": {"price": {"order": "desc"}}
}

返回结果如下:

{"took": 298,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": null,"hits": [{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": null,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/xm.jpg","price": 5999.00},"sort": [5999.0]},{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": null,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00},"sort": [3999.0]},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": null,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00},"sort": [1999.0]}]}
}
组合查询
  • bool 把各种其它查询通过 must(必须)、must not(必须不)、should(应该) 的方式进行组合

must 与查询

  • 假设想找出小米牌子,价格为 3999 元的。(must 相当于 sql 的 and
  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:
{"query": {"bool": {"must": [{"match": {"category": "小米"}},{"match": {"price": 3999.00}}]}}
}

返回结果如下:

{"took": 119,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 1,"relation": "eq"},"max_score": 2.89712,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 2.89712,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}}]}
}

should 或查询

  • 假设想找出小米和华为牌子。(should 相当于 sql 的 or
  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:
{"query": {"bool": {"should": [{"match": {"category": "小米"}},{"match": {"category": "华为"}}]}}
}

返回结果如下:

  • 字段不是关键词类型,会分词查询
{"took": 13,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 3,"relation": "eq"},"max_score": 1.89712,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.89712,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": 1.3862942,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/xm.jpg","price": 5999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 0.6931471,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}}]}
}
范围查询

range 查询找出那些落在指定区间内的数字或者时间。range 查询允许以下字符

操作符说明
gt大于 >
gte大于等于 >=
lt小于 <
lte小于等于 <=
  • 假设想找出小米和华为的牌子,价格大于 4000 元的手机。

  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"bool": {"should": [{"match": {"category": "小米"}},{"match": {"category": "华为"}}],"filter": {"range": {"price": {"gt": 4000}}}}}
}

返回结果如下:

{"took": 40,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 1,"relation": "eq"},"max_score": 1.3862942,"hits": [{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": 1.3862942,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/xm.jpg","price": 5999.00}}]}
}
完全匹配

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"match_phrase": {"category": "小米"}}
}

返回结果如下:

  • 不会进行分词查询
{"took": 65,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 1,"relation": "eq"},"max_score": 1.89712,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.89712,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}}]}
}
高亮查询

向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"query": {"match_phrase": {"category": "米"}},"highlight": {"fields": {"category": {} // 高亮这字段}}
}

返回结果如下:

{"took": 403,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 2,"relation": "eq"},"max_score": 0.6931471,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 0.6931471,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00},"highlight": {"category": ["小<em>米</em>"]}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 0.6931471,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00},"highlight": {"category": ["红<em>米</em>"]}}]}
}
聚合查询

分组查询示例

聚合允许使用者对 es 文档进行统计分析,类似与关系型数据库中的 group by,当然还有很多其他的聚合,例如取最大值 max、平均值 avg 等等。

接下来按 price 字段进行分组:

  • 新增个相同 price 的数据

  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:

{"aggs": { //聚合操作"price_group": { //名称,随意起名"terms": { //分组"field": "price" //分组字段}}}
}

返回结果如下:

{"took": 1309,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 4,"relation": "eq"},"max_score": 1.0,"hits": [{"_index": "shopping","_type": "_doc","_id": "psZeGZYBs2T-OKTlWq1C","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}},{"_index": "shopping","_type": "_doc","_id": "p8ZeGZYBs2T-OKTloK3v","_score": 1.0,"_source": {"title": "红米手机","category": "红米","images": "http://www.gulixueyuan.com/xm.jpg","price": 1999.00}},{"_index": "shopping","_type": "_doc","_id": "qMZfGZYBs2T-OKTlDK1W","_score": 1.0,"_source": {"title": "华为手机","category": "华为","images": "http://www.gulixueyuan.com/xm.jpg","price": 5999.00}},{"_index": "shopping","_type": "_doc","_id": "wcbjGZYBs2T-OKTlL62H","_score": 1.0,"_source": {"title": "小米手机","category": "小米","images": "http://www.gulixueyuan.com/xm.jpg","price": 3999.00}}]},"aggregations": {"price_group": {"doc_count_error_upper_bound": 0,"sum_other_doc_count": 0,"buckets": [{"key": 3999.0,"doc_count": 2},{"key": 1999.0,"doc_count": 1},{"key": 5999.0,"doc_count": 1}]}}
}

不返回原始数据写法

上面返回结果会附带原始数据的。若不想要不附带原始数据的结果,可以加多个 size 筛选属性:

{"aggs": {"price_group": {"terms": {"field": "price"}}},"size": 0
}

返回结果如下:

{"took": 10,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 4,"relation": "eq"},"max_score": null,"hits": []},"aggregations": {"price_group": {"doc_count_error_upper_bound": 0,"sum_other_doc_count": 0,"buckets": [{"key": 3999.0,"doc_count": 2},{"key": 1999.0,"doc_count": 1},{"key": 5999.0,"doc_count": 1}]}}
}

平均值查询示例

  • 向 ES 服务器发 GET 请求:http://127.0.0.1:9200/shopping/_search,附带 JSON 体如下:
{"aggs": {"price_avg": { // 名称,随意起名"avg": { // 求平均"field": "price"}}},"size": 0
}

返回结果如下:

{"took": 188,"timed_out": false,"_shards": {"total": 1,"successful": 1,"skipped": 0,"failed": 0},"hits": {"total": {"value": 4,"relation": "eq"},"max_score": null,"hits": []},"aggregations": {"price_avg": {"value": 3999.0}}
}

学习参考

  • 视频地址:【尚硅谷】ElasticSearch教程入门到精通(基于ELK技术栈elasticsearch 7.x+8.x新特性)_bilibili
  • 笔记地址:Elasticsearch学习笔记-CSDN博客
  • Elasticsearch 基础入门详文
  • Elasticsearch 保姆级入门篇
  • ElasticSearch在项目中具体怎么用? - 知乎
  • https://t.zsxq.com/4K41D

版权声明:

本网仅为发布的内容提供存储空间,不对发表、转载的内容提供任何形式的保证。凡本网注明“来源:XXX网络”的作品,均转载自其它媒体,著作权归作者所有,商业转载请联系作者获得授权,非商业转载请注明出处。

我们尊重并感谢每一位作者,均已注明文章来源和作者。如因作品内容、版权或其它问题,请及时与我们联系,联系邮箱:809451989@qq.com,投稿邮箱:809451989@qq.com