Salesforce Connector | How to Set One or More Fields of an Object to Null Using Update or Upsert Operation

In Salesforce Connector version 9.11.0 or earlier

You will find it under "Global Elements" tab -> double click on the "Salesforce Config" -> "General" tab -> "Advanced" Section -> "Can Clear Fields by Updating Field to Null" dropdown and select True.

In Salesforce Connector version 10.0.0 or later

Otherwise, if you leave it unchecked when using the "Invoke apex rest method" or "Invoke apex soap method" operation, or if you are using the Update or Upsert operation, you should modify your DataWeave Transform to make use of "fieldsToNull".

For example:

..
"FirstName": null,
(fieldsToNull: ["FirstName"]) if (payload.FirstName == null)

How to add more than one field to the fieldsToNull array using DataWeave?

%dw 2.0
output application/json
import * from dw::core::Objects
---
[{
	Id: '000012345',
	FirstName: payload.FirstName__c,
	MiddleName: payload.MiddleName__c,
	LastName: payload.LastName__c,
	Company: payload.Company__c,
    Email: payload.Email__c,
   ( fieldsToNull: valueSet(payload mapObject (( key: $$ ) if(($ == null) or (isEmpty($)))  )))
}]

%dw 2.0
output application/json
import * from dw::core::Objects
---
payload mapObject ((($$): $) if ($ != null)) ++
    "fieldsToNull": valueSet(payload mapObject (( key: $$ ) if(($ == null) or (isEmpty($))) )  )