Elasticsearch not find anything on the field with more words

Question

I'm trying elasticsearch and it looks great!

I noticed, however, a problem very uncomfortable, in a field that contains hello world if I search hello wo returns no result!

Why does this happen?

Place my configuration (FOSElasticaBundle):

fos_elastica:
clients:
    default: { host: localhost, port: 9200 }
serializer:
    callback_class: FOS\ElasticaBundle\Serializer\Callback
    serializer: serializer
indexes:
    website:
        client: default
        settings:
            index:
                analysis:
                    analyzer:
                        custom_search_analyzer:
                            type: custom
                            tokenizer: standard
                            filter   : [standard, worddelimiter, stopwords, snowball, lowercase, asciifolding]
                        custom_index_analyzer:
                            type: custom
                            tokenizer: nGram
                            filter   : [standard, worddelimiter, stopwords, snowball, lowercase, asciifolding]
                    filter:
                        stopwords:
                            type:      stop
                            stopwords: [_italian_]
                            ignore_case : true
                        worddelimiter :
                            type:       word_delimiter
                    tokenizer:
                        nGram:
                          type:     nGram
                          min_gram: 1
                          max_gram: 20
        types:
            structure:
                mappings:
                    name: { boost: 9, search_analyzer: custom_search_analyzer, index_analyzer: custom_index_analyzer, type: string }

Any idea on how to solve?

EDIT Here my query:

{
  query: {
    bool: {
        must: [ ]
        must_not: [ ]
        should: [
            {
                term: {
                    structure.name: hello wo
                }
            }
        ]
    }
}
  from: 0
  size: 10
  sort: [ ]
  facets: { }
}

EDIT 2

Ok, I don't understand this behavior ...

Now I run this query:

{
    query: {
        bool: {
            must: [
            {
                term: {
                    structure.name: hello
                }
            }
            {
                term: {
                    structure.name: wo
                }
            }
            ]
            must_not: [ ]
            should: [ ]
        }
    }
    from: 0
    size: 10
    sort: [ ]
    facets: { }
}

This query is the result I wanted, but I do not understand what is the difference in putting a must with two words and two must have a word with everyone!

I could explain this behavior?

Answer 1

Well i need to explain you probably how its working

When you index text elastic search will try to split it to terms if text is analyzed(as its in your mapping) so in your case "hello world" will be spited to two terms "hello" and "world" when you will do term search you write term hello world which does not fit any of your two terms.

To avoid spiting to terms you can set in mapping that field name is not analyzed, then it will not be spitted to two words and will be handled as one token.

Other solution is you can multiterm query

{
  "query": {
    "terms": {
      "structure.name": [
        "world",
        "hello"
      ]
    }
  }
}

Also when you use query_string it return result since it has different algorithm.

So depends on you needs you should use different queries, but to search by name you should use query_string, term should be used if you want to filter lets say categoryId, tags and stuff like that.