> > I want to insert a row unless it exists already. Do I have to write a
> > stored procedure to do this?
>[...]
> isn't a problem. If you need to do this in a transaction, you can
> simply set savepoints and roll back to the savepoint if an insert fails
> (and you expected that it could).
Yes, that's the problem: I have it in one transaction which I don't
want to fail on error. I'll look into the savepoint method.
Specifically the transaction I'm writing is a "Z SQL Method" in Zope
(a page templating system and web server).