接口冪等性：數(shù)學(xué)概念，多次請求，相當(dāng)于一次請求
get，put，delete都是冪等性的接口
post 存在冪等性的問題
前端速度很快，點(diǎn)了兩次，會生成兩個訂單
用戶在訪問新增頁面時（提交訂單）---》接口返回一個唯一id，提交訂單，攜帶唯一id過來，后端判斷這個唯一id是否被用過---》沒用過，創(chuàng)建訂單
你在項目中碰到的問題和如何解決（項目收獲）下訂單，經(jīng)常重復(fù)訂單，點(diǎn)得快，冪等性問題，如何解決的

倒排索引

1.es介紹10個點(diǎn)

2.安裝

-jdk ：java開發(fā)環(huán)境

官網(wǎng)下載es相應(yīng)的版本，解壓，到bin目錄下啟動elasticsearch.bat
兩個客戶端（kibana：官方，發(fā)送請求，數(shù)據(jù)統(tǒng)計，展示，elasticsearch-head：第三方用node寫的）
kibana跟es版本對應(yīng)，bin路徑下，直接啟動
elasticsearch-head需要安裝node環(huán)境，npm install ---》npm run start
kibana配置文件配置（copy一下，kibana監(jiān)聽的地址端口，隨便名一個名，連接es的地址）
修改es配置：允許跨域（瀏覽器的同源策略），cors：跨域資源共享，實現(xiàn)跨域
es的倒排索引（擴(kuò)展閱讀.md）
把文章進(jìn)行分詞，對每個詞建立索引

3 索引操作

# 索引操作---》數(shù)據(jù)庫操作---》新增，刪除，修改，查詢
# 1 新增索引：
PUT lqz2     # lqz2就是索引名字
{
  "settings": {
    "index":{
      "number_of_shards":5,
      "number_of_replicas":1
    }
  }
}
# 2 查詢索引
GET lqz2/_settings
返回結(jié)果
{
  "lqz2" : {
    "settings" : {
      "index" : {
        "creation_date" : "1588822389842",
        "number_of_shards" : "1",
        "number_of_replicas" : "1",
        "uuid" : "NBXIeVdHQ26vCuPn8_6uew",
        "version" : {
          "created" : "7050099"
        },
        "provided_name" : "lqz2"
      }
    }
  }
}
# 3 更新索引
PUT lqz2/_settings
{
  "number_of_replicas": 2
}
#4 刪除lqz2索引
DELETE lqz2

4 文檔基本增刪查改

#1  新增文檔
POST lqz2/_doc/1
{
  "title":"紅樓夢",
  "price":12,
  "publish_addr":{
    "province":"黑龍江",
    "city":"鶴崗"
  },
  "publish_date":"2013-11-11",
  "read_num":199,
  "tag":["古典","名著"]
}
POST lqz2/_doc/2
{
  "title":"西游記",
  "price":22,
  "publish_addr":{
    "province":"上海",
    "city":"上海"
  },
  "publish_date":"2013-11-11",
  "read_num":66,
  "tag":["古典","小說"]
}
# 2 查詢文檔（更詳細(xì)的查找，后面講）
GET lqz2/_doc/2
# 3 修改文檔
-覆蓋式（原來的字段就沒有了）
PUT lqz/_doc/1
{
  "title":"xxxx",
  "price":333,
  "publish_addr":{
    "province":"黑龍江",
    "city":"福州"
  }
}
-增量式（只修改某個字段）一定要注意包在doc中
POST lqz2/_doc/1/_update
{
  "doc":{
    "title":"xx"
  }
}
# 4 刪除文檔
DELETE lqz/_doc/1
# 5 批量獲取
GET _mget
{
  "docs":[
    {
      "_index":"lqz2",
      "_type":"_doc",
      "_id":2
    },
    {
      "_index":"lqz2",
      "_type":"_doc",
      "_id":1
    }
    ]
}
# 6 批量插入
PUT test/_doc/2/_create
{
  "field1" : "value22"
}
POST _bulk
{ "index" : { "_index" : "test", "_id" : "1" } }
{ "field1" : "value1" }
{ "delete" : { "_index" : "test", "_id" : "2" } }
{ "create" : { "_index" : "test", "_id" : "3" } }
{ "field1" : "value3" }
{ "update" : {"_id" : "1", "_index" : "test"} }
{ "doc" : {"field2" : "value2"} }

5 文檔查詢

# 測試數(shù)據(jù)
PUT lqz/doc/1
{
  "name":"顧老二",
  "age":30,
  "from": "gu",
  "desc": "皮膚黑、武器長、性格直",
  "tags": ["黑", "長", "直"]
}
PUT lqz/doc/2
{
  "name":"大娘子",
  "age":18,
  "from":"sheng",
  "desc":"膚白貌美，嬌憨可愛",
  "tags":["白", "富","美"]
}
PUT lqz/doc/3
{
  "name":"龍?zhí)灼?,
  "age":22,
  "from":"gu",
  "desc":"mmp，沒怎么看，不知道怎么形容",
  "tags":["造數(shù)據(jù)", "真","難"]
}
# 兩種方式
	-第一種（字符串查詢）
  	GET lqz/doc/_search?q=from:gu
    GET lqz/doc/_search?q=age:22
  -查詢的第二種方式（結(jié)構(gòu)化）
  	GET lqz/doc/_search
    {
      "query": {
        "match": {
          "from": "gu"
        }
      }
    }
    GET lqz/doc/_search
    {
      "query": {
        "match": {
          "age": 22
        }
      }
    }
   GET lqz/doc/_search
    {
      "query": {
        "match": {
          "desc": "形容"
        }
      }
    }
GET lqz/doc/_search
{
  "query": {
    "match": {
      "tags": "造數(shù)據(jù)"
    }
  }
}

以上就是Elasticsearch文檔索引基本操作增刪改查示例的詳細(xì)內(nèi)容，更多關(guān)于Elasticsearch文檔索引增刪改查的資料請關(guān)注腳本之家其它相關(guān)文章！

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