That is why everything in the world is not painted grey. There are those of us who find null values distinct and meaningful and those who don't. I personally prefer null (Unknown, etc.) values versus contrived values which in effect mean I don't like dealing with nulls so here's a blank string, or is that an empty string, missing value?
Or worse, zero vs. unknown? Damn! there goes the AVG(), Count(), and etc. function accuracy out the window! Oh well, it sure is easy to code! Fred > -----Original Message----- > From: Darren Duncan [mailto:[EMAIL PROTECTED] > Sent: Monday, November 27, 2006 6:51 PM > To: sqlite-users@sqlite.org > Subject: Re: [sqlite] SELECT on empty fields ?? > > > At 5:36 PM -0600 11/27/06, Jay Sprenkle wrote: > >On 11/27/06, Isaac Raway <[EMAIL PROTECTED]> wrote: > >>I'd like to strongly second this. Avoid NULL columns, even > at apparent cost. > >>Having a valid default value is always better. If a design > appears to > >>require NULL values, then the design is likely critically flawed. > > > >Using NULLS is NOT a critical design flaw. > >NULL means something specific and if you use it correctly it > works perfectly. > >NULL indicates when nothing has been entered into a field. > >Not entering anything, and entering spaces or a default > value, are different. > >If you need that information then it's very useful. If you don't then > >don't use it > >by assigning default values. > > Perhaps an intention behind the existence of NULLs was a useful idea, > but in practice, they are a big mess in SQL. > > The NULL is used in SQL for a multiplicity of unrelated meanings, > some of which are: value is unknown, no value is applicable here, > value is at its default / has yet to be assigned to, value can not be > determined, result of that operation is invalid. > > In fact, I read somewhere that there are a good 12 distint meanings > attached to NULLs, so we don't have 3-valued-logic, its > 14-valued-logic. > > But regardless, if you are given a NULL, how do you know what > it means? > > Moreover, SQL is inconsistent with itself in its treatment of NULLs, > in some situations treating 2 nulls as being distinct, and in other > situations treating them as non-distinct. > > So NULLs can be helpful to you if you are very careful, but often > they are more trouble than they are worth, and wherever possible, one > should use some other way to express the meaning of what they were > using NULLs for. > > -- Darren Duncan > > -------------------------------------------------------------- > --------------- > To unsubscribe, send email to [EMAIL PROTECTED] > -------------------------------------------------------------- > --------------- > ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
