How to do it...

Since we are changing the state of the data, the HTTP method is POST and the REST URL is as follows:

http://<server>/<index_name>/_update/<id>

To update a document, we will perform the following steps:

1. If we consider the type order of the previous recipe, the call to update a document will be as follows:

POST /myindex/_update/2qLrAfPVQvCRMe7Ku8r0Tw
{
  "script": {
    "source": "ctx._source.in_stock_items += params.count",
    "params": {
      "count": 4
    }
  }
}

1. If the request is successful, the result returned by Elasticsearch should be as follows:

{
  "_index" : "myindex",
  "_type" : "_doc",
  "_id" : "2qLrAfPVQvCRMe7Ku8r0Tw",
  "_version" : 4,
  "result" : "updated",
  "_shards" : {
    "total" : 2,
    "successful" : 1,
    "failed" : 0
  },
  "_seq_no" : 8,
  "_primary_term" : 1
}

1. The record will be as follows:

{
  "_index" : "myindex",
  "_type" : "_doc",
  "_id" : "2qLrAfPVQvCRMe7Ku8r0Tw",
  "_version" : 8,
  "_seq_no" : 12,
  "_primary_term" : 1,
  "found" : true,
  "_source" : {
    "id" : "1234",
    "date" : "2013-06-07T12:14:54",
    "customer_id" : "customer1",
    "sent" : true,
    "in_stock_items" : 4,
... truncated ...
  }
}

The visible changes are as follows:

• The scripted field has been changed
• The version has been incremented