By the way,
If anyone's interested I just wrote that intro to rules up into an
article on the techdocs.postgresql.org site :
http://techdocs.postgresql.org/techdocs/intropostgresqlrules.php
:-)
Regards and best wishes,
Justin Clift
Dr. Evil wrote :
> That's pretty cool. I may look into those. I just like being able
> to define that the data stay in a self-consistent format. Other
> programming languages would do well to follow this method. I'm
> programming my front-end in PHP. I should be able to say
>
> INT i CHECK (i > 0);
>
> when I declare it in PHP, for instance, but this isn't possible;
> they don't even have strong typing!
>
> Anyway, I was just writing a table which holds credit card payment
> data. I put in a constraint:
>
> cardnumber VARCHAR(20) CHECK (luhn10(cardnumber)),
>
> right in the table, so no matter how screwed up anything is, only
> valid card numbers can go in the table.
