In a StackOverflow clone, what relationship should a Comments table have to Questions and Answers?

Question

In an application similar to StackOverflow that I am building, I am trying to decide what relationship my Questions, Answers and Comments

Answer 1

You would need two domain tables that bring the relationships together CommentsForQuestions and CommentsForAnswers. Basically you're going to need to create 5 tables for this purpose:

Questions
Answers
Comments
CommentsForQuestions (relates comments to questions)
CommentsForAnswers (relates comments to answers)

The one problem this has is that it's inferior to the posts idea because referential integrity isn't as strong. I can garuntee that CommentsForQuestions connects to a comment and a question, but I can't prevent both a question and an answer from connecting to the same comment.