We are integrating with SFDC via the WSDL, and I'm curious to know the correct way to set the flag "Insert null values", similar to how the data loader and other tools allow you to overwrite an existing field value with null if it already contains a non-null value.

It appears that this must be set at the field level in the WSDL with a boolean flag, but other tools appear to set this at the operation or job level.

Any insight anyone could provide would be greatly appreciated.

Nick