thanks for your comments, really interesting. I'll come back to this post for ideas ;-). I like the precondition, maybe I'd like to structure it so that it pass

thanks for your comments, really interesting. I'll come back to this post for ideas ;-). I like the precondition, maybe I'd like to structure it so that it passes when 1+ rows are returned and fails if 0 rows... should be equivalent and doesn't make any assumption on rows _and_ columns being there... but I'll think about it. Thank you again!