Re: So what's null then if it's not nothing?

From: Jon Heggland <heggland_at_idi.ntnu.no>
Date: Thu, 15 Dec 2005 09:23:39 +0100
Message-ID: <MPG.1e0b465d32891c29989748_at_news.ntnu.no>


In article <3r81q1d8cfefnht3bkfo97ojcd1seail77_at_4ax.com>, hugo_at_pe_NO_rFact.in_SPAM_fo says...
>
> Here's what the standard says about comparisons between "booleans":
>
> "4.5.2 Comparison and assignment of booleans
>
> All boolean values and SQL truth values

That's a strange phrase. Does the standard separate between "boolean" and "SQL truth value"?

> are comparable and all are
> assignable to a site of type boolean. The value True is greater than the
> value False, and any comparison involving the null value or an Unknown
> truth value will return an Unknown result.

Thanks! This pretty much concludes the thread for my part.

> The values True and False may
> be assigned to any site having a boolean data type; assignment of
> Unknown, or the null value, is subject to the nullability
> characteristics of the target."

So we can all agree that a NOT NULL boolean column is a true boolean? This, at least, justifies the name somewhat.

-- 
Jon
Received on Thu Dec 15 2005 - 09:23:39 CET

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