Elasticsearch基本查询

痛定思痛。 2022-12-11 04:29 204阅读 0赞

**目录**

基本语法

查询所有（match\_all）

匹配查询（match）

多字段查询（multi\_match）

精确匹配（term）

多词条精确匹配（terms）

结果过滤

直接指定字段

指定includes和excludes

布尔组合查询（bool）

must、must\_not

should

filter

范围查询（range）

排序

单字段排序

多字段排序

分页

关键知识点总结

--------------------

## 基本语法 ##

POST /索引库名/_search
    {
        "query":{
            "查询类型":{
                "查询条件":"查询条件值"
            }
        }
    }

*  query：代表一个查询对象，里面可以有不同的查询属性；
 *  查询类型：例如：`match_all`， `match`，`term` ， `range` 等等；
 *  查询条件：查询条件会根据类型的不同，写法也有差异。

--------------------

## 查询所有（match\_all） ##

POST shop/_search
    {
      "query": {
        "match_all": {}
      }
    }

结果

{
      "took" : 1,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 5,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 1.0,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.0,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 1.0,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "1",
            "_score" : 1.0,
            "_source" : {
              "title" : "西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 15.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "3",
            "_score" : 1.0,
            "_source" : {
              "title" : "香蕉",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 2.3
            }
          }
        ]
      }
    }

*  took：查询花费时间，单位是毫秒
 *  time\_out：是否超时
 *  \_shards：分片信息
 *  hits：搜索结果总览对象
    
     *  total：搜索到的总条数
     *  max\_score：所有结果中文档得分的最高分
     *  hits：搜索结果的文档对象数组，每个元素是一条搜索到的文档信息
        
         *  \_index：索引库
         *  \_type：文档类型
         *  \_id：文档id
         *  \_score：文档得分
         *  \_source：文档的源数据

--------------------

## 匹配查询（match） ##

POST /shop/_search
    {
        "query":{
            "match":{
                "title":"麒麟西瓜"
            }
        }
    }

`match`类型查询，会把查询条件进行分词，然后进行查询,多个词条之间是or的关系，例如通过查询条件为麒麟西瓜，分词后与西瓜相关的记录都会查到。

{
      "took" : 11,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 3,
        "max_score" : 1.219939,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 1.219939,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 0.2876821,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "1",
            "_score" : 0.2876821,
            "_source" : {
              "title" : "西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 15.6
            }
          }
        ]
      }
    }

如果想使用match进行更精确的查找，可以指定operator属性为and：

POST /shop/_search
    {
      "query": {
        "match": {
          "title": {
            "query": "麒麟西瓜",
            "operator": "and"
          }
        }
      }
    }

结果：

{
      "took" : 11,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 1,
        "max_score" : 1.219939,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 1.219939,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          }
        ]
      }
    }

--------------------

## 多字段查询（multi\_match） ##

POST /shop/_search
    {
      "query": {
        "multi_match": {
          "query": "苹果",
          "fields": ["title","subtitle"]
        }
      }
    }

结果：

{
      "took" : 7,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 2,
        "max_score" : 1.2330425,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.2330425,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "v4e-03QB1qDLo16zF5gJ",
            "_score" : 0.2876821,
            "_source" : {
              "title" : "红富士",
              "images" : "http://image.xxx.com/12479122.jpg",
              "price" : 6,
              "subtitle" : "苹果"
            }
          }
        ]
      }
    }

--------------------

## 精确匹配（term） ##

`term` 查询被用于精确值匹配，这些精确值可能是数字、时间、布尔或者那些**未分词**的字符串。

POST /shop/_search
    {
        "query":{
            "term":{
                "price":3.6
            }
        }
    }

结果：

{
      "took" : 4,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 1,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.0,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          }
        ]
      }
    }

--------------------

## 多词条精确匹配（terms） ##

`terms` 查询和 term 查询一样，但它允许你指定多值进行匹配。如果这个字段包含了指定值中的任何一个值，那么这个文档满足条件，类似于mysql的in。

POST /shop/_search
    {
        "query":{
            "terms":{
                "price":[3.6,20.6]
            }
        }
    }

结果：

{
      "took" : 5,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 2,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.0,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 1.0,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          }
        ]
      }
    }

--------------------

## 结果过滤 ##

默认情况下，elasticsearch在搜索的结果中，会把文档中保存在`_source`的所有字段都返回。如果我们只想获取其中的部分字段，我们可以添加`_source`的过滤。

### **直接指定字段** ###

POST /shop/_search
    {
      "_source": ["title","price"],
      "query": {
        "term": {
          "price": 10.60
        }
      }
    }

结果：

{
      "took" : 5,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 1,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 1.0,
            "_source" : {
              "price" : 10.6,
              "title" : "京欣西瓜"
            }
          }
        ]
      }
    }

### **指定includes和excludes** ###

*  includes：来指定想要显示的字段；
 *  excludes：来指定不想要显示的字段。

POST /shop/_search
    {
      "_source": {
        "includes":["title","price"]
      },
      "query": {
        "term": {
          "price": 3.6
        }
      }
    }

POST /shop/_search
    {
      "_source": {
        "excludes":["images","price"]
      },
      "query": {
        "term": {
          "price": 3.6
        }
      }
    }

--------------------

## 布尔组合查询（bool） ##

bool查询包含四种操作符，分别是**must,should,must\_not,query**。它们均是一种数组，数组里面是对应的判断条件。

*  must： 必须匹配，与and等价，贡献算分；
 *  must\_not：必须不匹配，与not等价，常过滤子句用，但不贡献算分；
 *  should： 选择性匹配，至少满足一条，与 OR 等价，贡献算分；
 *  filter： 过滤子句，必须匹配，但不贡献算分。

### must、must\_not ###

POST /shop/_search
    {
      "query": {
        "bool": {
          "must": {
            "match": {
              "title": "西瓜"
            }
          },
          "must_not": {
            "match": {
              "price": "20.6"
            }
          }
        }
      }
    }

结果：

{
      "took" : 8,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 2,
        "max_score" : 0.2876821,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 0.2876821,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "1",
            "_score" : 0.2876821,
            "_source" : {
              "title" : "西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 15.6
            }
          }
        ]
      }
    }

### should ###

should类似于or，只要有一个条件满足即可：

POST /shop/_search
    {
      "query": {
        "bool": {
          "should": [{
            "match": {
              "title": "苹果"
            }
          },{
            "match": {
              "price": "20.6"
            }
          }]
        }
      }
    }

结果：

{
      "took" : 5,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 2,
        "max_score" : 1.2330425,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.2330425,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 1.0,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          }
        ]
      }
    }

### filter ###

会查询对结果进行缓存，不会计算相关度，避免计算分值，执行速度非常快。

POST /shop/_search
    {
      "query": {
        "bool": {
          "filter": {
            "term": {
              "price": "20.6"
            }
          }
        }
      }
    }

结果：\_score属性为0

{
      "took" : 18,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 1,
        "max_score" : 0.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "4",
            "_score" : 0.0,
            "_source" : {
              "title" : "麒麟西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 20.6
            }
          }
        ]
      }
    }

--------------------

## 范围查询（range） ##

`range` 查询找出那些落在指定区间内的数字或者时间。

`range`查询允许以下字符：

POST /shop/_search
    {
        "query":{
            "range": {
                "price": {
                    "gte":  10,
                    "lt":   20
                }
            }
        }
    }

结果：

{
      "took" : 1,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 2,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 1.0,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "1",
            "_score" : 1.0,
            "_source" : {
              "title" : "西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 15.6
            }
          }
        ]
      }
    }

--------------------

## 排序 ##

### **单字段排序** ###

POST /shop/_search
    {
      "query": {
        "range": {
          "price": {
            "gte": 5,
            "lt": 20
          }
        }
      },
      "sort": [
        {
          "price": {
            "order": "desc"
          }
        }
      ]
    }

结果：

{
      "took" : 6,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 3,
        "max_score" : null,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "1",
            "_score" : null,
            "_source" : {
              "title" : "西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 15.6
            },
            "sort" : [
              15.6
            ]
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : null,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            },
            "sort" : [
              10.6
            ]
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "v4e-03QB1qDLo16zF5gJ",
            "_score" : null,
            "_source" : {
              "title" : "红富士",
              "images" : "http://image.xxx.com/12479122.jpg",
              "price" : 6,
              "subtitle" : "苹果"
            },
            "sort" : [
              6.0
            ]
          }
        ]
      }
    }

### **多字段排序** ###

POST /shop/_search
    {
      "query": {
        "range": {
          "price": {
            "gte": 5,
            "lt": 20
          }
        }
      },
      "sort": [
        {
          "price": {
            "order": "desc"
          }
        },
        {
          "_score": {
            "order": "desc"
          }
        }
      ]
    }

--------------------

## 分页 ##

POST /shop/_search
    {
      "query": {
        "match_all": {}
      },
      "size": 2,
      "from": 0
    }

*  size：每页显示多少条；
 *  from：当前页起始索引, int start = (pageNum - 1) \* size。

结果：

{
      "took" : 0,
      "timed_out" : false,
      "_shards" : {
        "total" : 5,
        "successful" : 5,
        "skipped" : 0,
        "failed" : 0
      },
      "hits" : {
        "total" : 6,
        "max_score" : 1.0,
        "hits" : [
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "5",
            "_score" : 1.0,
            "_source" : {
              "title" : "京欣西瓜",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 10.6
            }
          },
          {
            "_index" : "shop",
            "_type" : "goods",
            "_id" : "2",
            "_score" : 1.0,
            "_source" : {
              "title" : "苹果",
              "images" : "http://image.xxx.com/435252.jpg",
              "price" : 3.6
            }
          }
        ]
      }
    }

--------------------

## 关键知识点总结 ##

>  *  match 查询的时候，ES会根据你给定的字段提供合适的分析器，相当于模糊匹配,只包含其中一部分关键词就行；
>  *  term 查询不会有分析器分析的过程，一般被用于精确值匹配，这些精确值可能是数字、时间、布尔或者那些**未分词**的字符串；
>  *  must 为必须匹配，与and等价，贡献算分，查询时分数高的靠前；
>  *  must\_not 为必须不匹配，与not等价，常过滤子句用，但不贡献算分；
>  *  should 为选择性匹配，至少满足一条，与 OR 等价，贡献算分；
>  *  filter 为必须匹配，查询过程忽略算分，直接过滤匹配的数据，结果会被缓存，效率较高。