String lexicographic range query in Elasticsearch

Question

Is it possible to query Elasticsearch giving it a range of strings?

Something that I'd imagine like:

Sample Mapping:

     {
      "resource" : {
        "properties" : {
          "Title" : {
            "type" : "string"
          },
          "type_" : {
            "index" : "not_analyzed",
            "type" : "string"
          },
           "Summary" : {
            "format" : "dateOptionalTime",
            "type" : "date"
          }
        }
      }
    }

Sample Query:

{
  "size" : 10,
  "query" : {
    "filtered" : {
      "query" : {
        "bool" : {
          "should" : [ {
            "text" : {
              "Title" : {
                "query" : "AAA",
                "type" : "phrase_prefix"
              }
            }
          }, {
            "range" : {
              "Title" : {
                "from" : "BBB",
                "to" : "CCC",
                "include_lower" : true,
                "include_upper" : true
              }
            }
          } ],
          "minimum_number_should_match" : 1
        }
      },
      "filter" : {
        "and" : {
          "filters" : [{
            "or" : {
              "filters" : [ {
                "term" : {
                  "type_" : "personType"
                }
              } ]
            }
          } ]
        }
      }
    }
  }
}

Data Indexed: Resources with Titles 'AAA', 'BBB', 'CCC', 'DDD'

Result Resource with Title 'AAA' (range didn't select 'BBB' and 'CCC')

Any help appreciated

Answer 1

Yes, it is possible. The RangeQuery provided by the elasticsearch query DSL internally uses the lucene TermRangeQuery for field of type string. On the other hand, it uses the lucene NumericRangeQuery for field of type number/date.

Answer 2

By default ElasticSearch keeps all indexed data lowercase. It does not lowercase the queries, though. Great.

To wrap up: after sending the queries (from and to values) all in lowercase the range searching works like a charm.