70 lines
1.6 KiB
Plaintext
70 lines
1.6 KiB
Plaintext
[[query-dsl-exists-query]]
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=== Exists query
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++++
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<titleabbrev>Exists</titleabbrev>
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++++
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Returns documents that contain an indexed value for a field.
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An indexed value may not exist for a document's field due to a variety of reasons:
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* The field in the source JSON is `null` or `[]`
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* The field has `"index" : false` set in the mapping
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* The length of the field value exceeded an `ignore_above` setting in the mapping
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* The field value was malformed and `ignore_malformed` was defined in the mapping
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[[exists-query-ex-request]]
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==== Example request
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[source,console]
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----
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GET /_search
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{
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"query": {
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"exists": {
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"field": "user"
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}
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}
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}
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----
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[[exists-query-top-level-params]]
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==== Top-level parameters for `exists`
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`field`::
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(Required, string) Name of the field you wish to search.
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+
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While a field is deemed non-existant if the JSON value is `null` or `[]`, these
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values will indicate the field does exist:
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+
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* Empty strings, such as `""` or `"-"`
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* Arrays containing `null` and another value, such as `[null, "foo"]`
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* A custom <<null-value, `null-value`>>, defined in field mapping
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[[exists-query-notes]]
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==== Notes
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[[find-docs-null-values]]
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===== Find documents missing indexed values
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To find documents that are missing an indexed value for a field,
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use the `must_not` <<query-dsl-bool-query, boolean query>> with the `exists`
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query.
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The following search returns documents that are missing an indexed value for
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the `user` field.
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[source,console]
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----
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GET /_search
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{
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"query": {
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"bool": {
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"must_not": {
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"exists": {
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"field": "user"
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}
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}
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}
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}
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}
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----
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