Terms set query

Returns documents that contain a minimum number of exact terms in a provided field.

The terms_set query is the same as the terms query, except you can define the number of matching terms required to return a document. For example:

• A field, programming_languages, contains a list of known programming languages, such as c++, java, or php for job candidates. You can use the terms_set query to return documents that match at least two of these languages.
• A field, permissions, contains a list of possible user permissions for an application. You can use the terms_set query to return documents that match a subset of these permissions.

In most cases, you’ll need to include a numeric field mapping in your index to use the terms_set query. This numeric field contains the number of matching terms required to return a document.

To see how you can set up an index for the terms_set query, try the following example.

1. Create an index, job-candidates, with the following field mappings:

   • name, a keyword field. This field contains the name of the job candidate.
   • programming_languages, a keyword field. This field contains programming languages known by the job candidate.
   • required_matches, a numeric long field. This field contains the number of matching terms required to return a document.

    PUT /job-candidates {
     "mappings": {
       "properties": {
         "name": {
           "type": "keyword"
         },
         "programming_languages": {
           "type": "keyword"
         },
         "required_matches": {
           "type": "long"
         }
       }
     }
   }
   

2. Index a document with an ID of 1 and the following values:

   • Jane Smith in the name field.
   • ["c++", "java"] in the programming_languages field.
   • 2 in the required_matches field.

   Include the ?refresh parameter so the document is immediately available for search.

    PUT /job-candidates/_doc/1?refresh {
     "name": "Jane Smith",
     "programming_languages": [ "c++", "java" ],
     "required_matches": 2
   }
   

3. Index another document with an ID of 2 and the following values:

   • Jason Response in the name field.
   • ["java", "php"] in the programming_languages field.
   • 2 in the required_matches field.

    PUT /job-candidates/_doc/2?refresh {
     "name": "Jason Response",
     "programming_languages": [ "java", "php" ],
     "required_matches": 2
   }
   

You can now use the required_matches field value as the number of matching terms required to return a document in the terms_set query.

The following search returns documents where the programming_languages field contains at least two of the following terms:

• c++
• java
• php

The minimum_should_match_field is required_matches. This means the number of matching terms required is 2, the value of the required_matches field.

 GET /job-candidates/_search {
  "query": {
    "terms_set": {
      "programming_languages": {
        "terms": [ "c++", "java", "php" ],
        "minimum_should_match_field": "required_matches"
      }
    }
  }
}

<field>

(Required, object) Field you wish to search.

terms

(Required, array) Array of terms you wish to find in the provided <field>. To return a document, a required number of terms must exactly match the field values, including whitespace and capitalization.

The required number of matching terms is defined in the minimum_should_match, minimum_should_match_field or minimum_should_match_script parameters. Exactly one of these parameters must be provided.

minimum_should_match

(Optional) Specification for the number of matching terms required to return a document.

For valid values, see minimum_should_match parameter.

minimum_should_match_field

(Optional, string) Numeric field containing the number of matching terms required to return a document.

minimum_should_match_script

(Optional, string) Custom script containing the number of matching terms required to return a document.

For parameters and valid values, see Scripting.

For an example query using the minimum_should_match_script parameter, see How to use the minimum_should_match_script parameter.

You can use minimum_should_match_script to define the required number of matching terms using a script. This is useful if you need to set the number of required terms dynamically.

The following search returns documents where the programming_languages field contains at least two of the following terms:

• c++
• java
• php

The source parameter of this query indicates:

• The required number of terms to match cannot exceed params.num_terms, the number of terms provided in the terms field.
• The required number of terms to match is 2, the value of the required_matches field.

 GET /job-candidates/_search {
  "query": {
    "terms_set": {
      "programming_languages": {
        "terms": [ "c++", "java", "php" ],
        "minimum_should_match_script": {
          "source": "Math.min(params.num_terms, doc['required_matches'].value)"
        },
        "boost": 1.0
      }
    }
  }
}