一、新增

1、创建索引

PUT product_db
{
  "mappings": {
    "properties": {
      "id": {
        "type": "long"
      },
      "name": {
        "type": "text",
        "analyzer": "ik_max_word"
      },
      "keywords": {
        "type": "text",
        "analyzer": "ik_max_word"
      },
      "subTitle": {
        "type": "text",
        "analyzer": "ik_max_word"
      },
      "salecount": {
        "type": "long"
      },
      "putawayDate": {
        "type": "date",
        "format": "yyyy-MM-dd HH:mm:ss||yyyy-MM-dd||epoch_millis"
      },
      "price": {
        "type": "double"
      },
      "promotionPrice": {
        "type": "keyword"
      },
      "originalPrice": {
        "type": "keyword"
      },
      "pic": {
        "type": "keyword"
      },
      "sale": {
        "type": "long"
      },
      "hasStock": {
        "type": "boolean"
      },
      "brandId": {
        "type": "long"
      },
      "brandName": {
        "type": "keyword"
      },
      "brandImg": {
        "type": "keyword"
      },
      "categoryId": {
        "type": "long"
      },
      "categoryName": {
        "type": "keyword"
      },
      "attrs": {
        "type": "nested",
        "properties": {
          "attrId": {
            "type": "long"
          },
          "attrName": {
            "type": "keyword"
          },
          "attrValue": {
            "type": "keyword"
          }
        }
      }
    }
  }
}

上方语句表示新建一个名称为product_db的索引

可能碰到的问题：

org.elasticsearch.index.mapper.MapperParsingException: analyzer [ik_max_word] not found for field [name]

原因是：当前安装的elasticsearch没有安装ik分词器
解决办法：

进入 elasticsearch 安装目录下的 bin\ 目录，在此目录打开命令行窗口，输入下面代码安装IK分词器插件
elasticsearch-plugin install https://github.com/medcl/elasticsearch-analysis-ik/releases/download/vX.X.X/elasticsearch-analysis-ik-X.X.X.zip

注意：上方指令中的X.X.X表示的是当前安装的elasticsearch的版本号

2、新增数据

PUT /product_db/_doc/1
{
  "id": "26",
  "name": "小米 11 手机",
  "keywords": "小米手机",
  "subTitle": "AI智慧全面屏 6GB +64GB 亮黑色 全网通版 移动联通电信4G手机 双卡双待双卡双待",
  "price": "3999",
  "promotionPrice": "2999",
  "originalPrice": "5999",
  "pic": "http://macro‐oss.oss‐cn‐shenzhen.aliyuncs.com/mall/images/20180615/xiaomi.jpg",
  "sale": 999,
  "hasStock": true,
  "salecount": 999,
  "putawayDate": "2021-04-01",
  "brandId": 6,
  "brandName": "小米",
  "brandImg": "http://macro‐oss.oss‐cn‐shenzhen.aliyuncs.com/mall/images/20190129/1e34aef2a409119018a4c6258e39ecfb_222_222.png",
  "categoryId": 19,
  "categoryName": "手机通讯",
  "attrs": [
    {
      "attrId": 1,
      "attrName": "cpu",
      "attrValue": "2核"
    },
    {
      "attrId": 2,
      "attrName": "颜色",
      "attrValue": "黑色"
    }
  ]
}

上方语句表明在product_db索引下新增一个序号为1的数据文档

二、修改

POST /product_db/_update/1
{
  "doc":{
    "name": "小米12pro hahha"
  }
}

上方的指令表示：将序号为1的文档中属性名为name的属性修改成对应的字符串，相当于：
update product_db set name="小米12pro hahha" where _id=1

三、查询

1、获取索引属性

GET product_db

上方指令表示查询product_db索引的具体属性

2、查询所有数据

GET product_db/_search
{
  "query": {
    "match_all": {}
  }
}

上方指令表示查询product_db索引下的所有数据，相当于：
select * from product_db

3、分页查询数据

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

上方指令表示从序号10的文档开始向后查询10条数据，相当于：
select * from product_db where _id >=10 limit 10

注意：如果size没有设置的话，默认是10

4、排序查询数据

GET product_db/_search
{
  "query": { "match_all": {} },
  "sort": { "price": { "order": "desc" } }
}

上方指令表示查询出的数据以price字段值倒序，相当于
select * from product_db order by price desc limit 10

5、查询指定字段数据

GET product_db/_search
{
  "query": { "match_all": {} },
  "_source": ["id", "name", "price"]
}

上方指令表示查询所有数据中的id、name、price三个字段，相当于：
select id, name, price from product_db

6、条件查询

GET product_db/_search
{
  "query": { "match": { "price": 3999 } }
}

上方指令表示只查询price是3999的数据，相当于：
select * from product_db where price=3999

7、模糊查询

只要不是数字类型，使用match都是模糊查询

GET product_db/_search
{
  "query": { "match": { "name": "小米" } }
}

GET product_db/_search
{
  "query": { "match": { "name": "小米 华为" } }
}

上方两条指令分别相当于：
select * from product_db where name like '%小米%'
select * from product_db where name like '%小米' or name like '%华为%'

注意：后面一个指令的小米只是以小米为后缀的模糊查询，而不是任意包含小米字段的模糊查询

8、与、或、非查询

GET product_db/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "name": "小米" } },
        { "match": { "name": "华为" } }
      ],
      "should": [
        { "match": { "name": "苹果" } },
        { "match": { "name": "三星" } }
      ],
      "must_not": [
        { "match": { "price": 2999 } }
      ]
    }
  }
}

上方指令是一个与、或、非组合查询语句，相当于：
select * from product_db where name like '%小米%华为%' or name like '%苹果%三星%' and price != 2999

9、范围查询

GET product_db/_search
{
  "query": {
    "bool": {
      "must": { "match_all": {} },
      "filter": {
        "range": {
          "price": {
            "gte": 2000,
            "lte": 5000
          }
        }
      }
    }
  }
}

上方指令相当于：
select * from product_db where price between 2000 and 5000

10、聚集查询

相当于SQL中的聚集函数，比如分组、求和、求平均数之类的

GET product_db/_search
{
  "size": 0,
  "aggs": {
    "group_by_brandId": {
      "terms": {
        "field": "brandId.keyword"
      }
    }
  }
}

上方指令相当于：
SELECT brandId, COUNT(*) FROM product_db GROUP BY brandId ORDER BY COUNT(*) DESC LIMIT 10;

GET product_db/_search
{
  "size": 0,
  "aggs": {
    "group_by_brandId": {
      "terms": {
        "field": "brandId.keyword"
      },
      "aggs": {
        "average_price": {
          "avg": {
            "field": "price"
          }
        }
      }
    }
  }
}

上方指令相当于：
SELECT brandId, COUNT(*), AVG(price) FROM product_db GROUP BY brandId ORDER BY COUNT(*) DESC LIMIT 10;

GET product_db/_search
{
  "size": 0,
  "aggs": {
    "group_by_salecount": {
      "range": {
        "field": "salecount",
        "ranges": [
          {
            "from": 2000,
            "to": 3000
          },
          {
            "from": 3000,
            "to": 4000
          },
          {
            "from": 4000,
            "to": 5000
          }
        ]
      },
      "aggs": {
        "group_by_brandId": {
          "terms": {
            "field": "brandId.keyword"
          },
          "aggs": {
            "average_balance": {
              "avg": {
                "field": "price"
              }
            }
          }
        }
      }
    }
  }
}