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

[[indices-get-field-mapping]]
== Get Field Mapping

The get field mapping API allows you to retrieve mapping definitions for one or more fields.
This is useful when you do not need the complete type mapping returned by
the <<indices-get-mapping>> API.

For example, consider the following mapping:

[source,js]
--------------------------------------------------
PUT publications
{
    "mappings": {
        "properties": {
            "id": { "type": "text" },
            "title":  { "type": "text"},
            "abstract": { "type": "text"},
            "author": {
                "properties": {
                    "id": { "type": "text" },
                    "name": { "type": "text" }
                }
            }
        }
    }
}
--------------------------------------------------
// TESTSETUP
// CONSOLE

The following returns the mapping of the field `title` only:

[source,js]
--------------------------------------------------
GET publications/_mapping/field/title
--------------------------------------------------
// CONSOLE

For which the response is:

[source,js]
--------------------------------------------------
{
   "publications": {
      "mappings": {
          "title": {
             "full_name": "title",
             "mapping": {
                "title": {
                   "type": "text"
                }
             }
          }
       }
   }
}
--------------------------------------------------
// TESTRESPONSE

[float]
=== Multiple Indices and Fields

The get field mapping API can be used to get the mapping of multiple fields from more than one index
with a single call. General usage of the API follows the
following syntax: `host:port/{index}/_mapping/field/{field}` where
`{index}` and `{field}` can stand for comma-separated list of names or wild cards. To
get mappings for all indices you can use `_all` for `{index}`. The
following are some examples:

[source,js]
--------------------------------------------------
GET /twitter,kimchy/_mapping/field/message

GET /_all/_mapping/field/message,user.id

GET /_all/_mapping/field/*.id
--------------------------------------------------
// CONSOLE
// TEST[setup:twitter]
// TEST[s/^/PUT kimchy\nPUT book\n/]

[float]
=== 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,js]
--------------------------------------------------
GET publications/_mapping/field/author.id,abstract,name
--------------------------------------------------
// CONSOLE

returns:

[source,js]
--------------------------------------------------
{
   "publications": {
      "mappings": {
        "author.id": {
           "full_name": "author.id",
           "mapping": {
              "id": {
                 "type": "text"
              }
           }
        },
        "abstract": {
           "full_name": "abstract",
           "mapping": {
              "abstract": {
                 "type": "text"
              }
           }
        }
     }
   }
}
--------------------------------------------------
// TESTRESPONSE

The get field mapping API also supports wildcard notation.

[source,js]
--------------------------------------------------
GET publications/_mapping/field/a*
--------------------------------------------------
// CONSOLE

returns:

[source,js]
--------------------------------------------------
{
   "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"
               }
            }
         }
      }
   }
}
--------------------------------------------------
// TESTRESPONSE

[float]
=== Other options

[horizontal]
`include_defaults`::

    adding `include_defaults=true` to the query string will cause the response
    to include default values, which are normally suppressed.