How to get specific fields from a document in Elasticsearch?

When you search or lookup a document, Elasticsearch by default returns or shows you all the fields in the document.

$ curl -X GET "localhost:9200/account/_doc/954?pretty"

{
  "_index" : "account",
  "_type" : "_doc",
  "_id" : "954",
  "_version" : 1,
  "_seq_no" : 790,
  "_primary_term" : 1,
  "found" : true,
  "_source" : {
    "account_number" : 954,
    "balance" : 49404,
    "firstname" : "Jenna",
    "lastname" : "Martin",
    "age" : 22,
    "gender" : "M",
    "address" : "688 Hart Street",
    "employer" : "Zinca",
    "email" : "jennamartin@zinca.com",
    "city" : "Oasis",
    "state" : "MD"
  }
}

But what if you want to display or fetch just a few fields from the document. 

Solution

It is quite simple to fetch just the required fields by specifying the fields in the _source attribute when doing the search.  Here is an example.

curl -X GET "localhost:9200/account/_search?pretty" -H 'Content-Type: application/json' -d'
{
    "_source": ["firstname", "lastname", "age"],
    "query" : {
        "term" : { "age" : "22" }
    }
}
'

Here is a sample output for the above search query. Here we are fetching only 3 fields from the document – firstname, lastname and age and we are fetching only documents with age 22.

{

  "took" : 23,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 51,
      "relation" : "eq"
    },
    "max_score" : 1.0,
    "hits" : [
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "75",
        "_score" : 1.0,
        "_source" : {
          "firstname" : "Sandoval",
          "age" : 22,
          "lastname" : "Kramer"
        }
      },
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "87",
        "_score" : 1.0,
        "_source" : {
          "firstname" : "Hewitt",
          "age" : 22,
          "lastname" : "Kidd"
        }
      },
      {
        "_index" : "account",
        "_type" : "_doc",
        "_id" : "227",
        "_score" : 1.0,
        "_source" : {
          "firstname" : "Coleman",
          "age" : 22,
          "lastname" : "Berg"
        }
      },