Update by query context [painless-update-by-query-context]

Use a Painless script in an update by query operation to add, modify, or delete fields within each of a set of documents collected as the result of query.

Check out the document update tutorial for related examples.

Variables

params (Map, read-only) : User-defined parameters passed in as part of the query.

ctx['op'] (String) : The name of the operation.

ctx['_routing'] (String, read-only) : The value used to select a shard for document storage.

ctx['_index'] (String, read-only) : The name of the index.

ctx['_id'] (String, read-only) : The unique document id.

ctx['_version'] (int, read-only) : The current version of the document.

ctx['_source'] (Map) : Contains extracted JSON in a Map and List structure for the fields existing in a stored document.

Side Effects

ctx['op'] : Use the default of index to update a document. Set to none to specify no operation or delete to delete the current document from the index.

ctx['_source'] : Modify the values in the Map/List structure to add, modify, or delete the fields of a document.

Return

void : No expected return value.

API

The standard Painless API is available.

Example

To run the example, first install the eCommerce sample data.

The following request uses the _update_by_query API to apply a discount to products that meet two conditions:

1. The product’s base_price is greater than or equal to 20.
2. The product currently has a discount_percentage of 0 (no discount applied).

POST /kibana_sample_data_ecommerce/_update_by_query
{
  "query": {
    "bool": {
      "filter": [
        {
          "range": {
            "products.base_price": {
              "gte": 20
            }
          }
        },
        {
          "match": {
            "products.discount_percentage": 0
          }
        }
      ]
    }
  },
  "script": {
    "lang": "painless",
    "source": """
        for (product in ctx._source.products) { 
            // If product has no discount applied 
            if (product.discount_percentage == 0) { 
                product.discount_percentage = params.discount_rate;  // Assigns the discount rate
                product.discount_amount = product.base_price * (params.discount_rate / 100) ; // Calculates and assigns the total discount

                product.price = product.base_price - product.discount_amount; // Calculates and assigns the product price with discount
            } 
        }
    """,
    "params": {
      "discount_rate": 15
    }
  }
}