Harald Fuchs said:
> In article <twig.1093012692.59157@kelcomaine.com>,
> "Jim Wilson" <jimw@kelcomaine.com> writes:
>
> > It'd probably be better design to not use the date as a flag. This issue
> > actually came up for me yesterday with an application that is now being ported
> > to Postgres. Previously a null "ship date" indicated that an item to be
> > shipped had not gone yet. I'm adding a flag, not just because of this issue
> > you describe, but it is also more intuitive for anyone looking at the data
> > who is unfamiliar with the business logic.
>
> Me thinks that's somewhat unclean. Is your shipDate nullable? If
> yes, what's the meaning of "shipDate IS NULL"? If no, what do you put
> in that field if notYetShipped is true?
Actually it would be a boolean "shipped" flag. ShipDate can be whatever you
want. Perhaps even null. All in all it just makes sense to use the boolean
when you need a flag (or integer or char for more than two flag states).
Best,
Jim