【ElasticSearch（八）进阶】filter过滤

• 布尔查询中的每个must、should和must not元素都称为查询子句。

  文档满足 must 或 should 子句中的标准的程度有助于文档的相关性得分。分数越高，文档就越符合我们的搜索条件。默认情况下，ElasticSearch返回会按照相关性得分对文档排序。

• must_not 子句中的条件，影响文档是否包含在结果中。

  filter、must_not 都不影响文档的得分。

• 还可以显式指定任意过滤器filter，以包含或排除基于结构化数据的文档。

【例子1】

查找年龄范围在 18 - 30 ，并且地址中包含 mill 的数据

range ：限制条件的范围

filter：过滤掉不符合条件的数据，且filter不会影响相关性得分。

GET /bank/_search
{
  "query":{
    "bool":{
      "filter":{
        "range":{
          "age":{
            "gte":18,
            "lte": 30
          }
        }
      },
      "must":{
        "match":{
         "address": "mill"
      }}
    }
  }
}

返回结果：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "Failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 5.4032025,
    "hits" : [
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "970",
        "_score" : 5.4032025,
        "_source" : {
          "account_number" : 970,
          "balance" : 19648,
          "firstname" : "Forbes",
          "lastname" : "Wallace",
          "age" : 28,
          "gender" : "M",
          "address" : "990 Mill Road",
          "employer" : "Pheast",
          "email" : "[email protected]",
          "city" : "Lopezo",
          "state" : "AK"
        }
      }
    ]
  }
}

【例子2】

我们可以看到想关心得分是0，filter并没有影响得分，只是筛选出了数据。

GET /bank/_search
{
  "query":{
    "bool":{
      "filter":{
        "range":{
          "age":{
            "gte":18,
            "lte": 30
          }
        }
      }
    }
  }
}

返回的结果是：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "Failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 498,
      "relation" : "eq"
    },
    "max_score" : 0.0,
    "hits" : [
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "13",
        "_score" : 0.0,
        "_source" : {
          "account_number" : 13,
          "balance" : 32838,
          "firstname" : "Nanette",
          "lastname" : "Bates",
          "age" : 28,
          "gender" : "F",
          "address" : "789 Madison Street",
          "employer" : "quility",
          "email" : "[e-mail]",
          "city" : "Nogal",
          "state" : "VA"
        }
      },
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "49",
        "_score" : 0.0,
        "_source" : {
          "account_number" : 49,
          "balance" : 29104,
          "firstname" : "Fulton",
          "lastname" : "Holt",
          "age" : 23,
          "gender" : "F",
          "address" : "451 Humboldt Street",
          "employer" : "Anocha",
          "email" : "[email protected]",
          "city" : "Sunriver",
          "state" : "RI"
        }
      },
      。。。
    ]
  }
}