OpenSearch/docs/reference/indices/get-field-mapping.asciidoc

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[[indices-get-field-mapping]]
=== Get field mapping API
++++
<titleabbrev>Get field mapping</titleabbrev>
++++
Retrieves <<mapping,mapping definitions>> for one or more fields. For data
streams, the API retrieves field mappings for the stream's backing indices.
This API is useful if you don't need a <<indices-get-mapping,complete mapping>>
or if an index mapping contains a large number of fields.
[source,console]
----
GET /my-index-000001/_mapping/field/user
----
// TEST[setup:my_index]
[[get-field-mapping-api-request]]
==== {api-request-title}
`GET /_mapping/field/<field>`
`GET /<target>/_mapping/field/<field>`
[[get-field-mapping-api-path-params]]
==== {api-path-parms-title}
`<target>`::
(Optional, string)
Comma-separated list of data streams, indices, and index aliases used to limit
the request. Wildcard (`*`) expressions are supported.
+
To target all indices in a cluster, omit this parameter or use `_all` or `*`.
`<field>`::
(Optional, string) Comma-separated list or wildcard expression of fields used to
limit returned information.
[[get-field-mapping-api-query-params]]
==== {api-query-parms-title}
include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=allow-no-indices]
+
Defaults to `true`.
include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=expand-wildcards]
include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=include-type-name]
include::{es-repo-dir}/rest-api/common-parms.asciidoc[tag=index-ignore-unavailable]
`include_defaults`::
(Optional, Boolean) If `true`, the response includes default mapping values.
Defaults to `false`.
`local`::
deprecated:[7.8.0, This parameter is a no-op and field mappings are always retrieved locally]
(Optional, boolean) If `true`, the request retrieves information from the local
node only. Defaults to `false`, which means information is retrieved from
the master node.
[[get-field-mapping-api-example]]
==== {api-examples-title}
[[get-field-mapping-api-basic-ex]]
===== Example with index setup
You can provide field mappings when creating a new index. The following
<<indices-create-index, create index>> API request creates the `publications`
index with several field mappings.
[source,console]
--------------------------------------------------
PUT /publications
{
"mappings": {
"properties": {
"id": { "type": "text" },
"title": { "type": "text" },
"abstract": { "type": "text" },
"author": {
"properties": {
"id": { "type": "text" },
"name": { "type": "text" }
}
}
}
}
}
--------------------------------------------------
The following returns the mapping of the field `title` only:
[source,console]
--------------------------------------------------
GET publications/_mapping/field/title
--------------------------------------------------
// TEST[continued]
The API returns the following response:
[source,console-result]
--------------------------------------------------
{
"publications": {
"mappings": {
"title": {
"full_name": "title",
"mapping": {
"title": {
"type": "text"
}
}
}
}
}
}
--------------------------------------------------
[[get-field-mapping-api-specific-fields-ex]]
===== Specifying fields
The get mapping API allows you to specify a comma-separated list of fields.
For instance to select the `id` of the `author` field, you must use its full name `author.id`.
[source,console]
--------------------------------------------------
GET publications/_mapping/field/author.id,abstract,name
--------------------------------------------------
// TEST[continued]
returns:
[source,console-result]
--------------------------------------------------
{
"publications": {
"mappings": {
"author.id": {
"full_name": "author.id",
"mapping": {
"id": {
"type": "text"
}
}
},
"abstract": {
"full_name": "abstract",
"mapping": {
"abstract": {
"type": "text"
}
}
}
}
}
}
--------------------------------------------------
The get field mapping API also supports wildcard notation.
[source,console]
--------------------------------------------------
GET publications/_mapping/field/a*
--------------------------------------------------
// TEST[continued]
returns:
[source,console-result]
--------------------------------------------------
{
"publications": {
"mappings": {
"author.name": {
"full_name": "author.name",
"mapping": {
"name": {
"type": "text"
}
}
},
"abstract": {
"full_name": "abstract",
"mapping": {
"abstract": {
"type": "text"
}
}
},
"author.id": {
"full_name": "author.id",
"mapping": {
"id": {
"type": "text"
}
}
}
}
}
}
--------------------------------------------------
[[get-field-mapping-api-multi-index-ex]]
===== Multiple targets and fields
The get field mapping API can be used to get mappings for multiple fields from
multiple data streams or indices with a single request.
The `<target>` and `<field>` request path parameters both support
comma-separated lists and wildcard expressions.
You can omit the `<target>` parameter or use a value of `*` or `_all` to target
all data streams and indices in a cluster.
Similarly, you can omit the `<field>` parameter or use a value of `*` to
retrieve mappings for all fields in the targeted data streams or indices.
However, the `<field>` parameter does not support the `_all` value.
For example, the following request retrieves mappings for the `message` field in
any data stream or index named `my-index-000001` or `my-index-000002`.
[source,console]
----
GET /my-index-000001,my-index-000002/_mapping/field/message
----
// TEST[setup:my_index]
// TEST[s/^/PUT my-index-000002\n/]
The following request retrieves mappings for the `message` and `user.id` fields
in any data stream or index in the cluster.
[source,console]
----
GET /_all/_mapping/field/message
----
// TEST[setup:my_index]
The following request retrieves mappings for fields with an `id` property in any
data stream or index in the cluster.
[source,console]
----
GET /_all/_mapping/field/*.id
----
// TEST[setup:my_index]