Re: Examples of SQL anomalies?
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 26 Jun 2008 19:43:07 -0300
Message-ID: <48641b7e$0$4066$9a566e8b_at_news.aliant.net>
>
>
> Others have mentioned nulls. One of my pet peeves in this area
> is that in SQL, if I sum zero numbers, the result is null.
> Mathematically, the result is 0. I have an app where I have had make
> adjustments where it is possible that zero numbers are summed.
>
> Try this one about duplicates:
> http://www.dbdebunk.com/page/page/627052.htm
Date: Thu, 26 Jun 2008 19:43:07 -0300
Message-ID: <48641b7e$0$4066$9a566e8b_at_news.aliant.net>
Gene Wirchenko wrote:
> "Artemus Ward" <artemus.ward_at_no.viagra.thanks> wrote:
>
>
>>Before I waste a big chunk of next week, does anyone know of any docs on the >>web that attempt to gather together examples of anomolous behaviour in >>standard SQL? I am thinking particularly of things like inconsistent >>treatment of nulls. I've got a couple of (to me) very obvious examples but >>there must be many more. >> >>Failing that, can anyone suggest good Google search terms that might return >>a manageable number of hits? Nothing I've tried has been very useful.
>
>
> Others have mentioned nulls. One of my pet peeves in this area
> is that in SQL, if I sum zero numbers, the result is null.
> Mathematically, the result is 0. I have an app where I have had make
> adjustments where it is possible that zero numbers are summed.
>
> Try this one about duplicates:
> http://www.dbdebunk.com/page/page/627052.htm
My personal favorite:
SUM(A) + SUM(B) != SUM(A+B) Received on Fri Jun 27 2008 - 00:43:07 CEST