Language / About the Polish vocative case - expressing affection? [6]

Hello,

I'm trying to find out about the vocative case. I've read that the vocative case is often used to express affection; what I want to know is, in these circumstances where the vocative case is being used to express affection, if you were addressing someone, would you use the nickname form of their name? For example, I read that the vocative form of Dawid is Dawidzie. If a wife had a husband called Dawid, is this how she would address him -- Dawidzie? Or, is there a vocative form of Dawidek, and if so, what is it?

Thank you!