[plug] [OT] MySQL Question....

[Arie Hol]

On 10 Aug 2006 at 22:30, Bernd Felsche wrote:

> "Timothy White" <weirdit at gmail.com> writes:
 
> In SQL-world, NULL means *unknown*. The equality of two unknowns is
> unknown. The uniqueness of the rows is only "broken" if identical
> values fill the previously-NULL.
> 
> An index should treat NULL as unknown and therefore assume that the
> NULL in that column doesn't match any value; or NULL itself.
> 
> That doesn't btw mean that you can't explicitly test for NULL
> (unknown).
> 
> >Anyone know how I might be able to do this? Or is it a case of having 
to
> >redesign that part of the database??
> 

For some things of interest about "NULL", goto :

http://www.blitzwiki.org/index.php/Null

and :

http://www.psoug.org/reference/null.html

and :

http://www.hudzilla.org/phpbook/read.php/9_3_20

and :

http://www.netfunny.com/rhf/jokes/new90/nullang.html



Regards Arie
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