[[set-processor]]
=== Set processor
++++
<titleabbrev>Set</titleabbrev>
++++

Sets one field and associates it with the specified value. If the field already exists,
its value will be replaced with the provided one.

[[set-options]]
.Set Options
[options="header"]
|======
| Name        | Required | Default | Description
| `field`     | yes      | -       | The field to insert, upsert, or update. Supports <<template-snippets,template snippets>>.
| `value`     | yes*     | -       | The value to be set for the field. Supports <<template-snippets,template snippets>>. May specify only one of `value` or `copy_from`.
| `copy_from` | no       | -       | The origin field which will be copied to `field`, cannot set `value` simultaneously. Supported data types are `boolean`, `number`, `array`, `object`, `string`, `date`, etc.
| `override`  | no       | `true`  | If `true` processor will update fields with pre-existing non-null-valued field. When set to `false`, such fields will not be touched.
| `ignore_empty_value` | no | `false` | If `true` and used in combination with `value` which is a <<template-snippets,template snippet>> that evaluates to `null` or an empty string, the processor quietly exits without modifying the document. Similarly, if used in combination with `copy_from` it will quietly exit if the field does not exist or its value evaluates to `null` or an empty string.
| `media_type` | no       | `application/json` | The media type for encoding `value`. Applies only when `value` is a <<template-snippets,template snippet>>. Must be one of `application/json`, `text/plain`, or `application/x-www-form-urlencoded`.
include::common-options.asciidoc[]
|======

[source,js]
--------------------------------------------------
{
  "description" : "sets the value of count to 1",
  "set": {
    "field": "count",
    "value": 1
  }
}
--------------------------------------------------
// NOTCONSOLE

This processor can also be used to copy data from one field to another. For example:

[source,console]
--------------------------------------------------
PUT _ingest/pipeline/set_os
{
  "description": "sets the value of host.os.name from the field os",
  "processors": [
    {
      "set": {
        "field": "host.os.name",
        "value": "{{{os}}}"
      }
    }
  ]
}

POST _ingest/pipeline/set_os/_simulate
{
  "docs": [
    {
      "_source": {
        "os": "Ubuntu"
      }
    }
  ]
}
--------------------------------------------------

Result:

[source,console-result]
--------------------------------------------------
{
  "docs" : [
    {
      "doc" : {
        "_index" : "_index",
        "_id" : "_id",
        "_version" : "-3",
        "_source" : {
          "host" : {
            "os" : {
              "name" : "Ubuntu"
            }
          },
          "os" : "Ubuntu"
        },
        "_ingest" : {
          "timestamp" : "2019-03-11T21:54:37.909224Z"
        }
      }
    }
  ]
}
--------------------------------------------------
// TESTRESPONSE[s/2019-03-11T21:54:37.909224Z/$body.docs.0.doc._ingest.timestamp/]

This processor can also access array fields using dot notation:
[source,console]
--------------------------------------------------
POST /_ingest/pipeline/_simulate
{
  "pipeline": {
    "processors": [
      {
        "set": {
          "field": "my_field",
          "value": "{{{input_field.1}}}"
        }
      }
    ]
  },
  "docs": [
    {
      "_index": "index",
      "_id": "id",
      "_source": {
        "input_field": [
          "Ubuntu",
          "Windows",
          "Ventura"
        ]
      }
    }
  ]
}
--------------------------------------------------

Result:

[source,console-result]
--------------------------------------------------
{
  "docs": [
    {
      "doc": {
        "_index": "index",
        "_id": "id",
        "_version": "-3",
        "_source": {
          "input_field": [
            "Ubuntu",
            "Windows",
            "Ventura"
          ],
          "my_field": "Windows"
        },
        "_ingest": {
          "timestamp": "2023-05-05T16:04:16.456475214Z"
        }
      }
    }
  ]
}
--------------------------------------------------
// TESTRESPONSE[s/2023-05-05T16:04:16.456475214Z/$body.docs.0.doc._ingest.timestamp/]


The contents of a field including complex values such as arrays and objects can be copied to another field using `copy_from`:
[source,console]
--------------------------------------------------
PUT _ingest/pipeline/set_bar
{
  "description": "sets the value of bar from the field foo",
  "processors": [
    {
      "set": {
        "field": "bar",
        "copy_from": "foo"
      }
    }
  ]
}

POST _ingest/pipeline/set_bar/_simulate
{
  "docs": [
    {
      "_source": {
        "foo": ["foo1", "foo2"]
      }
    }
  ]
}
--------------------------------------------------

Result:

[source,console-result]
--------------------------------------------------
{
  "docs" : [
    {
      "doc" : {
        "_index" : "_index",
        "_id" : "_id",
        "_version" : "-3",
        "_source" : {
          "bar": ["foo1", "foo2"],
          "foo": ["foo1", "foo2"]
        },
        "_ingest" : {
          "timestamp" : "2020-09-30T12:55:17.742795Z"
        }
      }
    }
  ]
}
--------------------------------------------------
// TESTRESPONSE[s/2020-09-30T12:55:17.742795Z/$body.docs.0.doc._ingest.timestamp/]