ElasticSearch：根据字段长度过滤文档？

Question

有没有办法根据特定字段的长度过滤ElasticSearch文档？

例如，我有一堆带有“body”字段的文档，我只想返回body中字符数为＆gt;的结果。 1000.有没有办法在ES中执行此操作而无需在索引中添加长度为额外的列？

Answer 1

使用脚本过滤器，如下所示：

"filtered" : {
    "query" : {
        ...
    }, 
    "filter" : {
        "script" : {
            "script" : "doc['body'].length > 1000"
        }
    }
}

修改 对不起，打算参考the query DSL guide on script filters

Answer 2

您还可以创建自定义标记生成器并在multifields属性中使用它，如下所示：

PUT test_index
{
  "settings": {
    "analysis": {
      "analyzer": {
        "character_analyzer": {
          "type": "custom",
          "tokenizer": "character_tokenizer"
        }
      },
      "tokenizer": {
        "character_tokenizer": {
          "type": "nGram",
          "min_gram": 1,
          "max_gram": 1
        }
      }
    }
  }, 
  "mappings": {
    "person": {
      "properties": {
        "name": { 
          "type": "text",
          "fields": {
            "keyword": { 
              "type": "keyword"
            },
            "words_count": { 
              "type": "token_count",
              "analyzer": "standard"
            },
            "length": { 
              "type": "token_count",
              "analyzer": "character_analyzer"
            }
          }
        }
      }
    }
  }
}

PUT test_index/person/1
{
  "name": "John Smith"
}

PUT test_index/person/2
{
  "name": "Rachel Alice Williams"
}

GET test_index/person/_search
{
  "query": {
    "term": {
      "name.length": 10
    }
  }
}