I, too, prefer NULL, but...

oli.sennhauser@fromdual.com (Oli Sennhauser) — Sat, 06 Aug 2011 13:19:17 +0200

If you’re using NULL to represent “anytime in the past/future” for DATETIME, that means that you need “special handling” for what would otherwise be simple inequalities.

For examples, I often store validity ranges with DATETIME; but that means I can no longer query if “valid_from > ‘2011-07-22 00:00:00’”, since that will through out any ( valid_from = NULL ) records. That’s not what I mean here – if the valid_from is NULL, that means they are always valid.

So in these particular cases, I prefer to use ‘0’ and ‘9999-12-31’ as special values so that index usage is correct and WHERE clauses are simplified.

But otherwise, yes, if NULL means “unknown”, as opposed to “special”, I entirely agree.

I, too, prefer NULL, but... on FromDual GmbH

I, too, prefer NULL, but...