I tried to find a solution to this but have been unsuccessful thus far so it would be nice if it were mentioned in the book. My apologies if it’s in the errata already but I didn’t see it there.
You can define a Default Value for an attribute but how to go about overriding the default value on a relationship? For example in GrokkingRecipes there’s an Authors entity which populates the Authors pop-up. Recipe has a relationship with Authors. If the recipe is new the default value for Author is “No Value”.
While I understand that it needs to say something to show nil it would be good to be able to change that to something other than “No Value” which I find misleading.