一、elasticsearch入门（基本介绍）

Love The Way You Lie 2022-06-02 09:37 257阅读 0赞

## 工具 ##

**sql转换** **[https://github.com/NLPchina/elasticsearch-sql/][https_github.com_NLPchina_elasticsearch-sql]**  
**Elasticsearch权威指南 [https://www.gitbook.com/book/looly/elasticsearch-the-definitive-guide-cn/details][https_www.gitbook.com_book_looly_elasticsearch-the-definitive-guide-cn_details]**

## Query-DSL 常用关键字： ##

> query,search\_type  
> term,terms, match,match\_phrase,multi\_match,fuzzy  
> bool,and,or,not,limit,must,must\_not,should  
> range,size,from,to,gt,gte,lt,lte  
> field,fields ,aggs,count,sum,min,max,avg

## windows环境搭建 ##

> Elasticsearch是一个基于Apache Lucene(TM)的开源搜索引擎。 无论在开源还是专有领域， Lucene可以被认为是迄今为止最先进、 性能最好的、 功能最全的搜索引擎库。

1.  分布式的实时文件存储， 每个字段都被索引并可被搜索
2.  分布式的实时分析搜索引擎
3.  可以扩展到上百台服务器， 处理PB级结构化或非结构化数据

本文使用windows版本

> Kibana [https://www.elastic.co/cn/downloads/kibana][https_www.elastic.co_cn_downloads_kibana]  
> Elasticsearch [https://www.elastic.co/cn/downloads/elasticsearch][https_www.elastic.co_cn_downloads_elasticsearch]

![Kibana][]

## 基本概念 ##

在Elasticsearch中， 文档归属于一种类型(type),而这些类型存在于索引(index)中， 我们可以画一些简单的对比图来类比传统关系型数据库：

> Relational DB -> Databases -> Tables -> Rows -> Columns  
> Elasticsearch -> Indices -> Types -> Documents -> Fields  
> Elasticsearch -> 索引-> 类型-> 文档-> 字段

## 基本语法 ##

PUT /megacorp/employee/1
    {
    "first_name" : "John",
    "last_name" : "Smith",
    "age" : 25,
    "about" : "I love to go rock climbing",
    "interests": [ "sports", "music" ]
    }
    
    PUT /megacorp/employee/2
    {
    "first_name" : "Jane",
    "last_name" : "Smith",
    "age" : 32,
    "about" : "I like to collect rock albums",
    "interests": [ "music" ]
    }
    
    PUT /megacorp/employee/3
    {
    "first_name" : "Douglas",
    "last_name" : "Fir",
    "age" : 35,
    "about": "I like to build cabinets",
    "interests": [ "forestry" ]
    }

GET /megacorp/employee/1
    GET /megacorp/employee/_search   ---搜索全部
    
    链接方式
    GET /megacorp/employee/_search?q=last_name:Smith
    
    使用DSL语句查询
     GET /megacorp/employee/_search
     {
       "query": {
         "match": {
           "last_name": "Smith"
         }
       }
     }
     更复杂的搜索
    GET /megacorp/employee/_search
    {
      "query": {
        "bool": {
          "filter": {
            "range": {
              "age": {
                "gte": 10,
                "lte": 30
              }
            }
          }
        }
      }
    }

**全文搜索**

GET /megacorp/employee/_search
    {
        "query" : {
         "match" : {
          "about" : "rock climbing"
          }
        }
    }

**短语搜索**

GET /megacorp/employee/_search
    {
        "query" : {
            "match_phrase" : {
                "about" : "rock climbing"
                }
            }
    }

**搜索高亮**

GET /megacorp/employee/_search
    {
      "query" : {
      "match_phrase" : {
      "about" : "rock climbing"
      }
    },
      "highlight": {
      "fields" : {
      "about" : {}
        }
      }
    }

**分析**

GET /megacorp/employee/_search
    {
    "aggs": {
    "all_interests": {
    "terms": { "field": "interests.keyword" }
            }
        }
    }
    
    
    聚合也允许分级汇总。 例如， 让我们统计每种兴趣下职员的平均年龄：
    GET /megacorp/employee/_search
    {
    "aggs" : {
      "all_interests" : {
         "terms" : { "field" : "interests.keyword"},
          "aggs" : {
                "avg_age" : {
                "avg" : { "field" : "age" }
               }
         }
        }
      }
    }

[https_github.com_NLPchina_elasticsearch-sql]: https://github.com/NLPchina/elasticsearch-sql/
[https_www.gitbook.com_book_looly_elasticsearch-the-definitive-guide-cn_details]: https://www.gitbook.com/book/looly/elasticsearch-the-definitive-guide-cn/details
[https_www.elastic.co_cn_downloads_kibana]: https://www.elastic.co/cn/downloads/kibana
[https_www.elastic.co_cn_downloads_elasticsearch]: https://www.elastic.co/cn/downloads/elasticsearch
[Kibana]: /images/20220602/d7fa2426ed3546f9bbeab6b099bab692.png