I haven't really done any database specific stuff in a while so I thought this might be a good time to point you to a great article, which references another great article, on the subject of NULL(s). I happen to love the subject of NULL(s) because it is as close as you can get to metaphysical philosophy in the database world. Usually database stuff is pretty dry. Rows and columns, columns and rows. Not very thought provoking. NULL on the other hand is everything that doesn't make sense about data. I have never been sold on the idea of the NULL value. It isn't a value, and in fact isn't anything. But that is different than nothing which is what I might have opted for. Having said that, the value of NULL is obvious (By value, I mean worth, not an actual value, which NULL does not have). So if NULL is something that is nothing how do you decide when to use it over using actually nothing? See now we are getting somewhere (somewhere that is actually nowhere, which is different that not being somewhere that is nowhere near somewhere). Wow, I better turn this over to Michael Coles, author of NULL Versus NULL? before I confuse all of us anymore. (This is an sqlservercentral link and does require registration. As I have said before, it is one of the best sql sites on the web, so if you haven't signed up before, do so now).
Enjoy your day!
"I can believe anything, provided that it is quite incredible."