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ElasticSearch的基础说明

2025-02-23 13:45:06   0  举报

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ElasticSearch的基础功能说明

ElasticSearch

功能说明

基础

作者其他创作

大纲/内容

类似于mysql

index对应表

mapping对应表结构

document对应表数据

索引的基本操作

创建索引

PUT /index_name

PUT /index_name
{
"aliases": {
"myindex_alias": {} // 创建别名
},
  "settings": {
    // 索引设置
    "number_of_shards": 1,    // 分片数量
    "number_of_replicas": 1    // 副本数量
  },
  "mappings": {
    "properties": {
      // 字段映射
      "name": {
        "type": "integer",
"null_value": 0
      },
      "age": {
        "type": "integer"
      },
      "enrolled_date": {
        "type": "date"
      },
"address": {
"type": "text",
"analyzer": "ik_smart" //或者最大分词ik_max_word
}
    }
  }
}

删除索引

DELETE /index_name

修改索引

PUT /index_name/_settings
{
"index": {
"属性名": "属性值"
}
}

PUT /index_name/_mapping
{
"properties": {
"字段名": "字段值" // 这个字段可以是新字段，这样就会新增一个字段
}
}

查看索引

GET /index_name

添加别名

POST /_aliases
{
"actions": [
{
"add": {
"index": "my_index", // 需要添加别名的索引
"alias": "my_index_alias" // 该索引的别名名称
}
}
]
}

多个索引，可以命名为同一个别名，便于查询，几乎不影响效率

相同别名的索引，建议字段保持一致

查询

POST index_1,index_2,index_3/_search

POST index_*/_search

文档的基本操作

新增

不指定id，由ES自动生成：
POST /index_name/_doc
{
"字段名": "值",
"字段名2": "值2"
}

会有幂等性问题，重复执行时，会重复插入同一条数据

指定id：
PUT /index_name/_doc/1
{
"字段名": "值",
"字段名2": "值2"
}

批量新增
POST /index_name/_bulk

修改

POST

更新时，可以只更新局部字段

POST /index_name/_update/{id}
{
"doc": {
"字段名": "xxx"
}
}

POST /index_name/_update_by_query
{
"query": {
"match": {
"字段名": "xxx"
}
},
"script": {
"source": "ctx._source.field = 'new_value'"
}
}

高并发环境下，需要待上这两个参数，确保线程安全
POST /index_name/_doc/1?if_seq_no=XX&if_primary_term=YYY
{
"字段名": "值",
"字段名2": "值2"
}

PUT

更新时，会覆盖整个文档，所以要写全，否则没更新的字段会被移除

删除

DELETE /index_name/_doc/{id}

DELETE /index_name/_delete_by_query
{
"query": {
"match": {
"字段名": "xxx"
}
}
}

批量操作

批量创建
POST _bulk
{"create":{"_index":"article","_id":3}}
{"id":3,"title":"xxx","tags":["xxx","yyy"],...}
{"create":{"_index":"article","_id":4}}
{"id":4,"title":"xxx","tags":["xxx","yyy"],...}

批量新建或替换
POST _bulk
{"index":{"_index":"article","_id":3}}
{"id":3,"title":"xxx","tags":["xxx","yyy"],...}
{"index":{"_index":"article","_id":4}}
{"id":4,"title":"xxx","tags":["xxx","yyy"],...}

批量更新
POST _bulk
{"update":{"_index":"article","_id":3}}
{"id":3,"title":"xxx","tags":["xxx","yyy"],...}
{"update":{"_index":"article","_id":4}}
{"id":4,"title":"xxx","tags":["xxx","yyy"],...}

批量删除
POST _bulk
{"delete":{"_index":"article","_id":3}}
{"delete":{"_index":"article","_id":4}}

也可以将上面的几个组合使用

查询

GET /index_name/_doc/{id}

GET /index_name/_mget
{
"ids": ["1","2","3"]
}

精确匹配
GET /index_name/_search
{
"query": {
"term": {
"name": "xxx"
}
}
}

全文检索
GET /index_name/_search
{
"query": {
"match": {
"name": "xxx"
}
}
}

范围检索
GET /index_name/_search
{
"query": {
"range": {
"age": {
"gte": 1,
"lte": 10
}
}
}
}

组合查询
GET /index_name/_search
{
"query": {
"bool": {
"must": [
{"match": {"字段名1": "xxx"}},
{"match": {"字段名2": "yyy"}},
]
}
}
}

如何处理关联关系

嵌套对象

type: "nested"