Elasticsearch 快速入门

Elasticsearch 基本操作

基本概念

集群，节点，索引，类型，文档，分片和副本

基本操作

# 查看分片大小
GET _cat/shards
# 查看集群运行状况
GET _cat/health?v
# 查看集群中的节点列表
GET _cat/nodes?v
# 查询集群中的索引
GET _cat/indices?v

elasticsearch支持restApi调用，执行http请求即可执行方法调用

索引（index）

创建索引

新建一个index:goods

curl -X PUT 'localhost:9200/goods'

对应的elasticsearch语法为：

# 创建索引（goods）
PUT /goods

响应为：

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "index" : "goods"
}

查询index

curl -X GET 'localhost:9200/goods'

删除index

curl -X DELETE 'localhost:9200/goods'

document（文档，数据）

新增数据

向指定的/goods/book发送请求

• goods:index
• book:type
• 1:id

PUT /goods/book/1
{
  "title":"elastic",
  "name":"elasticsearch学习笔记文档记录",
  "img":"img3.pic.com/56/8555.jpg",
  "price":"253.00"
}

指定id创建文档，id就是自定义的，如果不指定id，则会随机生成一个。

不指定id，创建数据

POST /goods/book
{
  "title":"elastic2",
  "name":"elasticsearch学习笔记文档记录",
  "img":"img3.pic.com/56/8555.jpg",
  "price":"253.00"
}

响应：

{
  "_index" : "goods",
  "_type" : "book",
  "_id" : "YU10yHoBrDuES6WZBDrL",
  "_version" : 1,
  "result" : "created",
  "_shards" : {
    "total" : 2,
    "successful" : 1,
    "failed" : 0
  },
  "_seq_no" : 1,
  "_primary_term" : 1
}

添加数据时，如果index不存在，就会创建对应的index

查看记录

curl localhost:9200/goods/book/1?pretty=true

{
  "_index" : "goods",
  "_type" : "book",
  "_id" : "1",
  "_version" : 1,
  "_seq_no" : 0,
  "_primary_term" : 1,
  "found" : true,
  "_source" : {
    "title" : "elastic",
    "name" : "elasticsearch学习笔记文档记录",
    "img" : "img3.pic.com/56/8555.jpg",
    "price" : "253.00"
  }
}

删除数据

curl -X DELETE localhost:9200/goods/book/1

更新数据

PUT /goods/book/1
{
  "title":"elastic33",
  "name":"elasticsearch学习笔记文档记录",
  "img":"img3.pic.com/56/8555.jpg",
  "price":"253.00"
}

{
  "_index" : "goods",
  "_type" : "book",
  "_id" : "1",
  "_version" : 2,
  "result" : "updated",
  "_shards" : {
    "total" : 2,
    "successful" : 1,
    "failed" : 0
  },
  "_seq_no" : 4,
  "_primary_term" : 1
}

变更后，_version会+1

查询所有记录

curl localhost:9200/goods/book/_search

条件查询（全查）

GET /dang-dang-goods/_search
{
  "query": {"match_all": {}}
}

分页查询

• size 查询数量
• from 偏移量

如果不指定size，默认为10

GET /goods/_search
{
  "query": {"match_all": {}},
  "from": 10, 
  "size": 5
}

排序

text类型不支持排序

对price进行倒排序

GET /goods/_search
{
  "query": {"match_all": {}},
  "sort": [
    {
      "price": {
        "order": "desc"
      }
    }
  ], 
  "from": 0, 
  "size": 10
}

返回特定字段

类似于SQL中的 SELECT sku,title FROM ...

只查询title，sku

GET goods/_search
{
  "query": {"match_all": {}},
  "_source": ["title","sku"]
}

条件查询（匹配）

查询title中包含背包的数据

GET /goods/_search
{
  "query": {"match": {
    "title": "背包"
  }}
}

查询title中包含背包或spring的数据

GET /goods/_search
{
  "query": {"match": {
    "title": "背包 spring"
  }}
}

布尔查询 (&&)

sku=1822023502 && price=¥79.00

GET /goods/_search
{
  "query": {
    "bool": {
      "must": [
        {"match": {"sku":"1822023502"}},
        {"match": {"price":"¥79.00"}}
      ]
    }
  }
}

布尔查询 (||)

sku=1822023502 || price=¥79.00

GET /goods/_search
{
  "query": {
    "bool": {
      "should": [
        {"match": {"sku":"1822023502"}},
        {"match": {"price":"¥79.00"}}
      ]
    }
  }
}

布尔查询 (!)

查询 !( sku=1822023502) && !(price=¥79.00)

GET /goods/_search
{
  "query": {
    "bool": {
      "must_not": [
        {"match": {"sku":"1822023502"}},
        {"match": {"price":"¥79.00"}}
      ]
    }
  }
}

条件查询(范围过滤)

查询price>100的数据

GET /goods/_search
{
  "query": {
    "bool": {
      "must": [
        {"match_all": {}}
      ],
      "filter": [
        {
         "range": {
           "price": {
             "gte": 100
           }
         } 
        }
      ]
    }
  }
}

统计查询（分组）

根据price分组

GET /goods/_search
{
  "size": 2,
  "aggs": {
    "group_by_price": {
      "terms": {
        "field": "price",
        "size": 100
      }
    }
  }
}

聚合查询(平均数)

按time求平均数

GET /goods/_search
{
  "size": 2,
  "aggs": {
    "group_by_price": {
      "terms": {
        "field": "price",
        "size": 100
      },
  "aggs": {
    "average_time": {
      "avg": {
        "field": "time"
      }
    }
  }
    }
  }
}