Re: pro- foreign key propaganda?

sinister wrote:
> I'm supervising the development of a database system with a web interface.
>
> I had built the DB backend using postgresql. The guy we hired to take over
> the project from me---I have non-IT duties to attend to---for various
> reasons decided to switch to MySQL and created his own tables (as well as
> redoing the web interface).
>
> After a conversation involving two tables which I thought ought to be
> connected by a foreign key relationship, I went and checked his DB; I was
> worried that he didn't fully understand the importance of using foreign
> keys. So I ran mysqldump and then did "grep -i foreign dump.sql" and
> "grep -i references dump.sql." Nothing!
>
> So...sent him an email late in the day, stressing that it's important that
> foreign keys be used where possible, that as much of the model
> logic/business logic/whatever should be encoded in the database itself to
> ensure data integrity, and so on.
>
> What do I do if he gets back to me and says---as I'm sure everyone in his
> position does---"oh, but my PHP code makes sure everything is done right"?
> Not that I don't know what to say, but it would be good to have a pointer to
> an essay or webpage that succinctly explains why you're asking for trouble
> if you don't encode such relationships in the DB itself.
>
> Sure, I could say, "Your next assignment is to read a book on DB theory, and
> give me a 10 minute summary," but we don't have that much time...
>
> :-(

If he is that much of a newb, make sure he is not using MyISAM. Maybe he didn't declare any integrity because he doesn't think mysql will enforce it in any case. But MyISAM can (will?) corrupt your data. Received on Thu May 15 2008 - 15:45:24 CEST