Re: Updating column on row update

Adrian Klaver <aklaver@comcast.net>

From: Adrian Klaver <aklaver@comcast.net>
To: pgsql-general@postgresql.org
Cc: Thom Brown <thombrown@gmail.com>, Scott Marlowe <scott.marlowe@gmail.com>
Date: 2009-11-22T21:20:40Z
Lists: pgsql-hackers, pgsql-general
On Sunday 22 November 2009 1:10:36 pm Thom Brown wrote:
> 2009/11/22 Scott Marlowe <scott.marlowe@gmail.com>
>
> > > Thanks Scott.  It's a shame a function has to be used because it then
> > > has the dependency of plpgsql being loaded.  I'm attempting to write a
> >
> > database
> >
> > > schema to accompany a PostgreSQL driver for a popular CMS, but I guess
> > > I could get it to load plpgsql in as a language.
> > > The problem now is if the the schema creation script is run against a
> > > database where the language is already installed, I would get an error
> > > saying it already exists.  Is there a way to get it to check for it
> >
> > first,
> >
> > > and only create it if it isn't exist?  Bear in mind I'd want this to be
> > > compatible at least as far back as 8.1.
> >
> > Try this:
> >
> > select * from pg_language ;
> >
> > Pretty sure that exists pretty far back.
>
> Yes, I noticed that existed in the catalogs, but how could that be
> incorporated into an installation SQL script?  The language constructs I
> imagine I'd need to test that are in plpgsql itself.
>
> Thanks
>
> Thom

As far as I know the language exists ERROR will not stop the rest of the process 
from completing. You may in search of solution to a problem that does not 
exist :)

-- 
Adrian Klaver
aklaver@comcast.net