Updating documents in Elasticsearch

Introduction

Updating documents lets you change information already saved in Elasticsearch without deleting and adding it again.

You want to fix a typo in a saved record.

You need to add new details to an existing document.

You want to increase a count or score stored in a document.

You want to change the status of an order or task.

You want to update a timestamp to show the last change.

Syntax

Elasticsearch

POST /index_name/_update/document_id
{
  "doc": {
    "field_name": "new_value"
  }
}

Use POST method with _update endpoint to change a document.

Inside the JSON body, use "doc" to specify only the fields you want to update.

Examples

This updates the price field of the document with ID 1 in the products index.

Elasticsearch

POST /products/_update/1
{
  "doc": {
    "price": 19.99
  }
}

This sets the last_login field to a new date for user with ID 42.

Elasticsearch

POST /users/_update/42
{
  "doc": {
    "last_login": "2024-06-01T12:00:00"
  }
}

This changes the status of order 100 to shipped.

Elasticsearch

POST /orders/_update/100
{
  "doc": {
    "status": "shipped"
  }
}

Sample Program

This updates the document with ID 123 in the library index, changing the title and availability.

Elasticsearch

POST /library/_update/123
{
  "doc": {
    "title": "Learn Elasticsearch",
    "available": true
  }
}

Important Notes

If the document does not exist, Elasticsearch can create it if you add "doc_as_upsert": true.

Only the fields inside "doc" are changed; other fields stay the same.

You can also use scripts to update fields based on their current values.

Summary

Use the _update API to change parts of a saved document.

Send only the fields you want to change inside the "doc" object.

Elasticsearch updates the document without replacing it fully.