Re: the case for machine-readable error fields

> Hmm, well, I skipped the rationale because it has been requested before.
> For example, we need to give constraint names so that applications can
> tell which unique key is being violated.  We need table names on which
> they are being violated.  We need column names for datatype mismatches,
> and so on.  We frequently see people parsing the error message to
> extract those, but that is known to be fragile, cumbersome and error
> prone.

If that's what we're trying to solve, I don't think that adding some
kind of proprietary shorthand coding is a good idea.  If we're do to
this at all, it should be a connection-based GUC option, and use some
standard formal like XML fragments.

-- 
Josh Berkus
PostgreSQL Experts Inc.
www.pgexperts.com