Elasticsearch lowercase filter search

问题

I'm trying to search my database and be able to use upper/lower case filter terms but I've noticed while query's apply analyzers, I can't figure out how to apply a lowercase analyzer on a filtered search. Here's the query:

{
    "query": {
        "filtered": {
            "filter": {
                "bool": {
                    "should": [
                        {
                            "term": {
                                "language": "mandarin" // Returns a doc
                            }
                        },
                        {
                            "term": {
                                "language": "Italian" // Does NOT return a doc, but will if lowercased
                            }
                        }
                    ]
                }
            }
        }
    }
}

I have a type languages that I have lowercased using:

"analyzer": {
    "lower_keyword": {
        "type": "custom",
        "tokenizer": "keyword",
        "filter": "lowercase"
    }
}

and a corresponding mapping:

"mappings": {
    "languages": {
        "_id": {
            "path": "languageID"
        },
        "properties": {
            "languageID": {
                "type": "integer"
            },
            "language": {
                "type": "string",
                "analyzer": "lower_keyword"
            },
            "native": {
                "type": "string",
                "analyzer": "keyword"
            },
            "meta": {
                "type": "nested"
            },
            "language_suggest": {
                "type": "completion"
            }
        }
    }
}

回答1:

The problem is that you have a field that you have analyzed during index to lowercase it, but you are using a term filter for the query which is not analyzed:

Term Filter

Filters documents that have fields that contain a term (not analyzed). Similar to term query, except that it acts as a filter.

http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-term-filter.html

I'd try using a query filter instead:

Query Filter

Wraps any query to be used as a filter. Can be placed within queries that accept a filter.

Example:

{
    "constantScore" : {
        "filter" : {
            "query" : {
                "query_string" : {
                    "query" : "this AND that OR thus"
                }
            }
        }
    } }

http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-query-filter.html#query-dsl-query-filter

来源：https://stackoverflow.com/questions/24811243/elasticsearch-lowercase-filter-search

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ElasticSearch