Output Data Tool - update, insert if new

One of the powerful things about the Alteryx Designer is that you can do most things related to your workflow right from within the workflow itself. One such operation is creating a Primary Key for your database table and namely using the Pre-Create SQL and Post- Create SQL options in the Input Data and Output Data tools to do that.

So far so good.

I then change the Output Data Tool to "Update; Insert if new". I get an error, which is also mentioned in the post: "Primary Key required for Update option…

Make sure a primary key is declared on the table."

But I have already added a Primary Key (verified this in SQL Management Server) - so what is missing?

Do I need to add some Pre- or Post-Create SQL statement to execute the Update and Insert actions? And if so, how should this be done? 

- Or should I be using some of the In Database tools instead of the standard Output Data Tool?

I sincerely hope that one of you in here can help me out. 

Kind regards,

Dorte