Daniel Convissor wrote: > This is useful, in part, for statistical purposes, since the null record > won't be added into averages, etc. For example, you had three surveys > filled out. Two people actually filled in their ages (10 and 20), if you > do an average when using nulls, you'll get an average age of 15. But if > you use 0's instead of nulls, the average age will incorrectly be 10.
Dan, this is very helpful--thank you! The light bulb is starting to come on in my head now... If anyone else has practical examples, please don't hold back. Bev _______________________________________________ New York PHP User Group Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk http://www.nyphp.org/show_participation.php
