【ElasticSearch（九）进阶】Term精确数值查询，match keyword精确文本查询

一、Term精确数值查询

• term查询，会返回那些 在提供的字段中包含确切信息 的文档内容。

• 查询text字段值，使用match。查询精确数值，使用term。

• 为什么避免使用term对text字段进行查询？

  默认情况下，ES更改text字段的值作为词法分析的一部分。这会使查找text字段值的精确匹配变得困难。

查询年龄是33岁的数据：

GET bank/_search
{
  "query":{
    "term":{
      "age": 33
    }
  }
}

返回结果：

{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 50,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "18",
        "_score" : 1.0,
        "_source" : {
          "account_number" : 18,
          "balance" : 4180,
          "firstname" : "Dale",
          "lastname" : "Adams",
          "age" : 33,
          "gender" : "M",
          "address" : "467 Hutchinson Court",
          "employer" : "Boink",
          "email" : "daleadams@boink.com",
          "city" : "Orick",
          "state" : "MD"
        }
      },
        。。。
    ]
  }
}

二、match keyword精确文本查询

下面对比下match，match_phrase，match中的属性加.keyword的区别

1.match 模糊查询文本

会将address的文本拆分成词，只要结果中包含有任意词的文档，都可以被筛选出来。

GET bank/_search
{
  "query":{
    "match":{
      "address": "467 Hutchinson Court"
    }
  }
}

返回结果：

{
  "took" : 17,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 120,
      "relation" : "eq"
    },
    "max_score" : 14.617203,
    "hits" : [
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "18",
        "_score" : 14.617203,
        "_source" : {
          "account_number" : 18,
          "balance" : 4180,
          "firstname" : "Dale",
          "lastname" : "Adams",
          "age" : 33,
          "gender" : "M",
          "address" : "467 Hutchinson Court",
          "employer" : "Boink",
          "email" : "daleadams@boink.com",
          "city" : "Orick",
          "state" : "MD"
        }
      },
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "53",
        "_score" : 5.990829,
        "_source" : {
          "account_number" : 53,
          "balance" : 28101,
          "firstname" : "Kathryn",
          "lastname" : "Payne",
          "age" : 29,
          "gender" : "F",
          "address" : "467 Louis Place",
          "employer" : "Katakana",
          "email" : "kathrynpayne@katakana.com",
          "city" : "Harviell",
          "state" : "SD"
        }
      },
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "56",
        "_score" : 2.1248586,
        "_source" : {
          "account_number" : 56,
          "balance" : 14992,
          "firstname" : "Josie",
          "lastname" : "Nelson",
          "age" : 32,
          "gender" : "M",
          "address" : "857 Tabor Court",
          "employer" : "Emtrac",
          "email" : "josienelson@emtrac.com",
          "city" : "Sunnyside",
          "state" : "UT"
        }
      },
     。。。
    ]
  }
}

2.match_phrase 短语查询

将address的文本视为一个短语，不进行文本拆分，只要结果中包含这个短语的文档，都能被筛选出来。

GET bank/_search
{
  "query":{
    "match_phrase":{
      "address": "467 Hutchinson"
    }
  }
}

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" : 12.492344,
    "hits" : [
      {
        "_index" : "bank",
        "_type" : "account",
        "_id" : "18",
        "_score" : 12.492344,
        "_source" : {
          "account_number" : 18,
          "balance" : 4180,
          "firstname" : "Dale",
          "lastname" : "Adams",
          "age" : 33,
          "gender" : "M",
          "address" : "467 Hutchinson Court",
          "employer" : "Boink",
          "email" : "daleadams@boink.com",
          "city" : "Orick",
          "state" : "MD"
        }
      }
    ]
  }
}

3.match中的属性加.keyword

keyword精确查询，只有结果中address属性和address.keyword的值完全一致的文档，才能被筛选出来。

结合2和3，可以发现同样的值，match_phrase 和 keyword的区别。

GET bank/_search
{
  "query":{
    "match":{
      "address.keyword": "467 Hutchinson"
    }
  }
}

返回结果：

{
  "took" : 4,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  }
}

*我们一般规定：全文检索字段用 match,其他非text字段匹配用term