Re: boolean datatype ... wtf?
Date: Wed, 06 Oct 2010 15:03:03 -0300
paul c wrote:
> On 06/10/2010 6:51 AM, Bob Badour wrote:
>> Null is an indicator that evaluates to NULL or NOT NULL. ie. it is a >> boolean.
> This makes me want to take another stab at an old point. I think it is
> a boolean and how it's constructed within a relational db seems crucial
> which I'd say it can't be in any logical way. Maybe this is part of
> what what Erwin S means too.
> It's reminiscent of how Table_Dee has a maximum cardinality of one,
You misspoke. Table_Dee has a cardinality of exactly one. Table_Dum has a cardinality of exactly zero. Nilary relations have a maximum cardinality of one and a minimum cardinality of zero. Received on Wed Oct 06 2010 - 13:03:03 CDT