[FIXED] ElasticSearch exact match on text in nested field - Java

Issue

The mapping contains nested field.

I'm wondering if it's possible to do an exact match on "value" without changing its type to "keyword".

"mappings": {
"properties": {
  "tag": {
    "type": "nested",
    "properties": {
      "value": {
        "type": "text"
      },
      "key": {
        "type": "keyword"
      }
    }
  }
}
}

Below is the code I tried to do an exact match on "value" field.

BoolQueryBuilder boolQ = boolQuery();
boolQ.must(matchQuery("tag.key", "key"));
boolQ.must(matchQuery("tag.value", "value").fuzziness(Fuzziness.ZERO));
entireQuery.must(nestedQuery("tag", boolQ, ScoreMode.None));

The above returned a result matched with tokenized words of "value" as well.

I would really appreciate if any references related to the question is present.

Solution

Since tag.value is of type text, its content has been analyzed and the resulting tokens (i.e. not exact value) have been indexed in Elasticsearch.

Even though the term query doesn't analyze the search token, it doesn't help here because the indexed tokens have already been analyzed.

There are now two options:

A. If tag.value only contains a single token (e.g. "Dog"), you can still match them exactly by using either term or match but by lowercasing the value, as in:

{
    "nested": {
       "path": "tag",
       "query":{
           "term":{
               "tag.value":"dog"
           }
       }
    }
}

B. If tag.value contains multiple tokens (e.g. "the big dog"), it is therefore not possible to search for their exact value anymore.

Answered By - Val
Answer Checked By - Cary Denson (JavaFixing Admin)