Re: boolean datatype ... wtf?

From: Bob Badour <>
Date: Wed, 06 Oct 2010 15:03:03 -0300
Message-ID: <4cacb9d8$0$14800$>

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 - 20:03:03 CEST

Original text of this message