I have a list - Companies - that is an External List based on an External Content Type from SQL Server. I have another list - Purchase Orders - that has a lookup column to the Companies table.
I am using Nintex Forms 2010, and when I create the form for the Purchase Orders list, I use a List Lookup control to select the Company from the Companies list. When I add an item, the dropdown populates with the values from the Companies list, but when I save the item, the Company field on the Purchase Orders list is blank.
I have noticed that when I use a lookup column for the Company field, I cannot connect the Nintext control to the column, but if I change the Company Column to a single line of text column, I can connect the List Lookup control to the Company column, but it still does not save the value.
Is there something I'm missing, or is it not possible to use an External List as a lookup column?