I would use the same REST web service for consuming the data and also for inserting the data into the table. For POST method, if I want to insert values into the table for only some of the fields, I would verify the following :
* The view which is exposed as REST web service should be “updateable” in order to perform Insert, Delete and Update operations.
* The fields which are not used in POST body must either allow null or declared with a default value in the source.
* Ensure to pass the values for all the non-nullable fields and the fields which are PRIMARY key or has UNIQUE constraint in the source.
You can refer to [IDU Requests](https://community.denodo.com/docs/html/browse/6.0/vdp/administration/restful_architecture/restful_web_service/idu_requests) section of Virtual DataPort Administration guide and [PUT / POST REST WS](https://community.denodo.com/answers/question/details?questionId=90670000000XcMkAAK&title=PUT+%2F+POST+REST+WS) community answer for more information.
Hope this helps!