OpenSearch/docs/reference/query-dsl/exists-query.asciidoc

[[query-dsl-exists-query]]
=== Exists query
++++
<titleabbrev>Exists</titleabbrev>
++++

Returns documents that contain an indexed value for a field.

An indexed value may not exist for a document's field due to a variety of reasons:

* The field in the source JSON is `null` or `[]`
* The field has `"index" : false` set in the mapping
* The length of the field value exceeded an `ignore_above` setting in the mapping
* The field value was malformed and `ignore_malformed` was defined in the mapping

[[exists-query-ex-request]]
==== Example request

[source,console]
----
GET /_search
{
  "query": {
    "exists": {
      "field": "user"
    }
  }
}
----

[[exists-query-top-level-params]]
==== Top-level parameters for `exists`
`field`::
(Required, string) Name of the field you wish to search.
+
While a field is deemed non-existent if the JSON value is `null` or `[]`, these
values will indicate the field does exist:
+
* Empty strings, such as `""` or `"-"`
* Arrays containing `null` and another value, such as `[null, "foo"]`
* A custom <<null-value, `null-value`>>, defined in field mapping

[[exists-query-notes]]
==== Notes

[[find-docs-null-values]]
===== Find documents missing indexed values
To find documents that are missing an indexed value for a field,
use the `must_not` <<query-dsl-bool-query, boolean query>> with the `exists`
query.

The following search returns documents that are missing an indexed value for
the `user.id` field.

[source,console]
----
GET /_search
{
  "query": {
    "bool": {
      "must_not": {
        "exists": {
          "field": "user.id"
        }
      }
    }
  }
}
----