Re: Preventing variables from "rolling over"

On 30 May 2001, Dr. Evil wrote:

>
> I assume that if I keep on adding to an INT4, at some point it will
> roll over and become negative, and then if I add some more, it could
> become positive. Is there a way to prevent this? Ie, I would like
> for it to end with an error instead of wrapping around. Or is there a
> way to check for this condition before I do the addition? Is there a
> way to put a constraint on a variable, such that it's always positive?
>
> Thanks

Not exactly, but close: use a sequence instead of an int4 and define the maxvalue to be the max positive for int. Also don't allow it to cycle. When it reaches the maxvalue you'll get an error.

cheers,
thalis