Search-as-you-type 字段类型 #

search-as-you-type 字段类型通过前缀和中缀补全提供边输入边搜索的功能。

代码样例 #

将字段映射为 search-as-you-type 类型时，会为该字段创建 n-gram 子字段，其中 n 的范围为 [2, max_shingle_size]。此外，还会创建一个索引前缀子字段。

创建一个 search-as-you-type 的映射字段

PUT books
{
  "mappings": {
    "properties": {
      "suggestions": {
        "type": "search_as_you_type"
      }
    }
  }
}

除了创建 suggestions 字段外，还会生成 suggestions._2gram、suggestions._3gram 和 suggestions._index_prefix 字段。

以下是使用 search-as-you-type 字段索引文档的示例：

PUT books/_doc/1
{
  "suggestions": "one two three four"
}

要匹配任意顺序的词项，可以使用 bool_prefix 或 multi-match 查询。

这些查询会将搜索词项按顺序匹配的文档排名提高，而将词项顺序不一致的文档排名降低。

GET books/_search
{
  "query": {
    "multi_match": {
      "query": "tw one",
      "type": "bool_prefix",
      "fields": [
        "suggestions",
        "suggestions._2gram",
        "suggestions._3gram"
      ]
    }
  }
}

返回内容包含匹配的文档：

{
  "took" : 13,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "books",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 1.0,
        "_source" : {
          "suggestions" : "one two three four"
        }
      }
    ]
  }
}

要按顺序匹配词项，可以使用 match_phrase_prefix 查询：

GET books/_search
{
  "query": {
    "match_phrase_prefix": {
      "suggestions": "two th"
    }
  }
}

返回内容包含匹配到的文档：

{
  "took" : 23,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.4793051,
    "hits" : [
      {
        "_index" : "books",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.4793051,
        "_source" : {
          "suggestions" : "one two three four"
        }
      }
    ]
  }
}

要精确匹配最后的词项，可以使用 match_phrase 查询：

GET books/_search
{
  "query": {
    "match_phrase": {
      "suggestions": "four"
    }
  }
}

返回内容：

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 1,
      "relation" : "eq"
    },
    "max_score" : 0.2876821,
    "hits" : [
      {
        "_index" : "books",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : 0.2876821,
        "_source" : {
          "suggestions" : "one two three four"
        }
      }
    ]
  }
}

参数说明 #

下表列出了 search-as-you-type 字段类型支持的参数，所有参数均为可选项。