Databasen - NULL dates
Paul Makepeace
paulm at paulm.com
Fri Oct 20 21:32:23 BST 2006
On 10/20/06, Ovid <publiustemp-londonpm at yahoo.com> wrote:
> NULLs in databases lead to problems like this. What's worse is when
> you return thousands of rows of data and only have a handful which are
> incorrectly excluded. The problem might very well go undetected.
> NULLs should only be used with great caution. People are quite
> cavalier about their use and happily throw them in any ol' table just
> because it's easier than figuring out the underlying problem
> (disclaimer: I've done the same thing, so "je m'accuse").
What he said!
I recently had to debug some datamining app that had a 1% error on its
reports (credit to the chap that actually spotted that). Even with
fore-knowledge of the evils of NULLs it still took me several hours to
get to the point I could adequately explain it to someone in
marketing.
P
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