[[docs-update]]
=== Update API
++++
<titleabbrev>Update</titleabbrev>
++++

Updates a document using the specified script.

[[docs-update-api-request]]
==== {api-request-title}

`POST /<index>/_update/<_id>`

[[update-api-desc]]
==== {api-description-title}

Enables you to script document updates. The script can update, delete, or skip
modifying the document. The update API also supports passing a partial document,
which is merged into the existing document. To fully replace an existing
document, use the <<docs-index_,`index` API>>.

This operation:

. Gets the document (collocated with the shard) from the index.
. Runs the specified script.
. Indexes the result.

The document must still be reindexed, but using `update` removes some network
roundtrips and reduces chances of version conflicts between the GET and the
index operation.

The `_source` field must be enabled to use `update`. In addition to `_source`,
you can access the following variables through the `ctx` map: `_index`,
`_type`, `_id`, `_version`, `_routing`, and `_now` (the current timestamp).

[[docs-update-api-path-params]]
==== {api-path-parms-title}

`<index>`::
(Required, string) Name of the target index. By default, the index is created
automatically if it doesn't exist. For more information, see <<index-creation>>.

`<_id>`::
(Required, string) Unique identifier for the document to be updated.

[[docs-update-api-query-params]]
==== {api-query-parms-title}

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=if_seq_no]

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=if_primary_term]

`lang`::
(Optional, string) The script language. Default: `painless`.

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=require-alias]

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=refresh]

`retry_on_conflict`::
(Optional, integer) Specify how many times should the operation be retried when
 a conflict occurs. Default: 0.

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=routing]

`_source`::
(Optional, list) Set to `false` to disable source retrieval (default: `true`).
You can also specify a comma-separated list of the fields you want to retrieve.

`_source_excludes`::
(Optional, list) Specify the source fields you want to exclude.

`_source_includes`::
(Optional, list) Specify the source fields you want to retrieve.

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=timeoutparms]

include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=wait_for_active_shards]

[[update-api-example]]
==== {api-examples-title}

First, let's index a simple doc:

[source,console]
--------------------------------------------------
PUT test/_doc/1
{
  "counter" : 1,
  "tags" : ["red"]
}
--------------------------------------------------

To increment the counter, you can submit an update request with the
following script:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script" : {
    "source": "ctx._source.counter += params.count",
    "lang": "painless",
    "params" : {
      "count" : 4
    }
  }
}
--------------------------------------------------
// TEST[continued]

Similarly, you could use and update script to add a tag to the list of tags
(this is just a list, so the tag is added even it exists):

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script": {
    "source": "ctx._source.tags.add(params.tag)",
    "lang": "painless",
    "params": {
      "tag": "blue"
    }
  }
}
--------------------------------------------------
// TEST[continued]

You could also remove a tag from the list of tags. The Painless
function to `remove` a tag takes the array index of the element
you want to remove. To avoid a possible runtime error, you first need to
make sure the tag exists. If the list contains duplicates of the tag, this
script just removes one occurrence.

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script": {
    "source": "if (ctx._source.tags.contains(params.tag)) { ctx._source.tags.remove(ctx._source.tags.indexOf(params.tag)) }",
    "lang": "painless",
    "params": {
      "tag": "blue"
    }
  }
}
--------------------------------------------------
// TEST[continued]

You can also add and remove fields from a document. For example, this script
adds the field `new_field`:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script" : "ctx._source.new_field = 'value_of_new_field'"
}
--------------------------------------------------
// TEST[continued]

Conversely, this script removes the field `new_field`:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script" : "ctx._source.remove('new_field')"
}
--------------------------------------------------
// TEST[continued]

Instead of updating the document, you can also change the operation that is
executed from within the script.  For example, this request deletes the doc if
the `tags` field contains `green`, otherwise it does nothing (`noop`):

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script": {
    "source": "if (ctx._source.tags.contains(params.tag)) { ctx.op = 'delete' } else { ctx.op = 'none' }",
    "lang": "painless",
    "params": {
      "tag": "green"
    }
  }
}
--------------------------------------------------
// TEST[continued]

[discrete]
===== Update part of a document

The following partial update adds a new field to the
existing document:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "doc": {
    "name": "new_name"
  }
}
--------------------------------------------------
// TEST[continued]

If both `doc` and `script` are specified, then `doc` is ignored. If you
specify a scripted update, include the fields you want to update in the script.

[discrete]
===== Detect noop updates

By default updates that don't change anything detect that they don't change
anything and return `"result": "noop"`:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "doc": {
    "name": "new_name"
  }
}
--------------------------------------------------
// TEST[continued]

If the value of `name` is already `new_name`, the update
request is ignored and the `result` element in the response returns `noop`:

[source,console-result]
--------------------------------------------------
{
   "_shards": {
        "total": 0,
        "successful": 0,
        "failed": 0
   },
   "_index": "test",
   "_type": "_doc",
   "_id": "1",
   "_version": 7,
   "_primary_term": 1,
   "_seq_no": 6,
   "result": "noop"
}
--------------------------------------------------

You can disable this behavior by setting `"detect_noop": false`:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "doc": {
    "name": "new_name"
  },
  "detect_noop": false
}
--------------------------------------------------
// TEST[continued]

[[upserts]]
[discrete]
===== Upsert

If the document does not already exist, the contents of the `upsert` element
are inserted as a new document.  If the document exists, the
`script` is executed:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "script": {
    "source": "ctx._source.counter += params.count",
    "lang": "painless",
    "params": {
      "count": 4
    }
  },
  "upsert": {
    "counter": 1
  }
}
--------------------------------------------------
// TEST[continued]

[discrete]
[[scripted_upsert]]
===== Scripted upsert

To run the script whether or not the document exists, set `scripted_upsert` to
`true`:

[source,console]
--------------------------------------------------
POST sessions/_update/dh3sgudg8gsrgl
{
  "scripted_upsert": true,
  "script": {
    "id": "my_web_session_summariser",
    "params": {
      "pageViewEvent": {
        "url": "foo.com/bar",
        "response": 404,
        "time": "2014-01-01 12:32"
      }
    }
  },
  "upsert": {}
}
--------------------------------------------------
// TEST[s/"id": "my_web_session_summariser"/"source": "ctx._source.page_view_event = params.pageViewEvent"/]
// TEST[continued]

[discrete]
[[doc_as_upsert]]
===== Doc as upsert

Instead of sending a partial `doc` plus an `upsert` doc, you can set
`doc_as_upsert` to `true` to use the contents of `doc` as the `upsert`
value:

[source,console]
--------------------------------------------------
POST test/_update/1
{
  "doc": {
    "name": "new_name"
  },
  "doc_as_upsert": true
}
--------------------------------------------------
// TEST[continued]
[NOTE]
====
Using <<ingest,ingest pipelines>> with `doc_as_upsert` is not supported.
====
