Franz wrote:
> Any idea about how to fill the "number_of_visit" field as requested in
> my previous post?

UPDATE club C SET C.number_of_visits = (SELECT count(*) FROM visits V
WHERE V.idclub = C.idclub);

But it is not a good idea, as I stated in my first post, because the
actual number of visits can change in the meantime, and someone might
see old data.