> But (in at least some situations) is not appropriate to record that you know that you don't have a value? >
Sure it would. It it's needed. But the answer doesn't have to be a NULL. Remember the example about recording the fact that a student did not make a test for whatever reason? It was then said you could store "null" for the test score. I then replied that that was a bit backward IMO, cause you're using the "test scores" table to store that a student did not take a test, which is wrong, given that each row in a table should mean exactly the same thing (theory knocking at the door once again) and that makes a design more clear. > I think the words of Donald Rumsfeld are appropriate here: > "There are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know." > I think we'll have a hard time storing Donalds "knows" and "unknowns" in a database... :-) > At 12:02 pm +0100 16/3/06, Martijn Tonies wrote: > >Well, the question still is if you should store "unknown" at all ;) > > > >Not according to Date: you should store what is known. > <snip> Martijn Tonies Database Workbench - development tool for MySQL, and more! Upscene Productions http://www.upscene.com My thoughts: http://blog.upscene.com/martijn/ Database development questions? Check the forum! http://www.databasedevelopmentforum.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
