I wrote some notes on three-valued logic (true,false,unknown) at my website:
http://www.comptechnews.com/~reaster/dbdesign.html#three-valued-logic
If anyone finds errors with it, please let me know.
On Wednesday 13 December 2000 19:03, Stephan Szabo wrote:
> On Wed, 13 Dec 2000, Al Lewis wrote:
On Wed, 13 Dec 2000, Al Lewis wrote:
> I am migrating to postgress from msql and am encountering numerous problems
> in the differences in NULL usage and comparison.
>
> 1. Why are 2 fields not equal if they are both NULL?
Because that's what the SQL spec says. If either value is NULL
the resu
I am migrating to postgress from msql and am encountering numerous problems
in the differences in NULL usage and comparison.
1. Why are 2 fields not equal if they are both NULL?
2. Is there a way to easily modify my sql select statements to account for
either column being NULL and having them re
