如何在 Elastic Search 中使用标准分析器搜索文本

Question

I have a key value pair indexed as text in ES Mapping.

{key:myKey, value:MY_VALUE}

Whatever I do, let it be term, match, terms it doesn't hit in ES when I try to query for value

So: MY_VALUE will convert to terms of [my, value]

Answer 1

If you use a match query without any modification then it uses the same analyzer which was used to index the field, ie generates the same types of token for your search term and should produce you the search result.

As per Elasticsearch Match query Doc:

The provided text is analyzed before matching.

The match query is the standard query for performing a full-text search

As you have not provided any sample, let me show it using my sample data:

Index def

{
  "mappings" :{
    "properties" :{
        "title" :{
            "type" : "text" --> default standard analyzer would be used.
        }
    }
  }
}

Index sample docs

{
    "title": "foo bar"
}

{
    "title": "hello world"
}

search for foo

{
    "query" :{
        "match" :{
            "title" :"foo"
        }
    }
}

Result

 "hits": [
            {
                "_index": "standard",
                "_type": "_doc",
                "_id": "1",
                "_score": 0.4700036,
                "_source": {
                    "title": "foo bar"
                }
            }
        ]

Search for foo bar

{
    "query" :{
        "match" :{
            "title" :"foo bar"
        }
    }
}

Result

"hits": [
            {
                "_index": "standard",
                "_type": "_doc",
                "_id": "1",
                "_score": 0.9400072,
                "_source": {
                    "title": "foo bar"
                }
            }
        ]

Note: Searching for foo and foo bar both matches as standard token split the tokens on whitespace and you can use analyze API to check that as shown below:

{
  "text" : "foo bar",
  "analyzer" : "standard"
}

{
    "tokens": [
        {
            "token": "foo",
            "start_offset": 0,
            "end_offset": 3,
            "type": "<ALPHANUM>",
            "position": 0
        },
        {
            "token": "bar",
            "start_offset": 4,
            "end_offset": 7,
            "type": "<ALPHANUM>",
            "position": 1
        }
    ]
}

Edit: Based on the comment from OP(@AKASH GUPTA)

Now Elastic provides a default keyword field for text field but that's only for dynamic mapping and not for the static mapping and that too in the latest versions. Please refer this blog post and if you are using static mapping you can define your own corresponding keyword field.

Answer 2

Moving comment to answer: "It seems Elastic Search by default provides keyword for text fields. In this case it can be used as "title.keyword".

Refer: https://www.elastic.co/blog/strings-are-dead-long-live-strings (Section: New Defaults.)

If you are having issues with "analyzed" text, and want a non analyzed string, you can append ".keyword" to your key. before that do check if the mapping is present similar to:

"yourKey": {
     "type": "text",
     "fields": {
           "keyword": {
                "type": "keyword",
                "ignore_above": 256
           }
      }
}

If its not present, update the mapping similar as above.