Re: Standard metadata queries

On Thu, 24 Apr 2008 11:01:13 -0700
Steve Atkins <steve(at)blighty(dot)com> wrote:

> I've been chatting with the Trolltech folks about the implementation
> of the Qt wrapper around libpq, and the issue of how to properly do
> metadata queries came up. That is things like "What are the column
> names and types of the primary key of this table, and what index
> enforces it?" or "What are the names and types of each field of this
> table?".
>
> These seem like queries that'll be used by a lot of people, hidden
> down in ORMs and access libraries, and which are hard to get right,
> let alone efficient, and which will generally be written by one
> person (developing the ORM or library) and likely not touched again.
>
> Is there a standard set of well-crafted implementations of these
> anywhere that could be used by all the interface and ORM developers?
> If not, would it make sense to put some together and document or
> wiki them? Both as example code and as a set of good, solid queries
> that library developers can cut and paste.
>
> (The implementation I'm looking at right now has, amongst other
> things, hardwired OID-to-type mappings, and there's got to be a
> cleaner way than that).

I believe the information_schema is standard.

Joshua D. Drake

>
> Cheers,
> Steve
>
>

--
The PostgreSQL Company since 1997: http://www.commandprompt.com/
PostgreSQL Community Conference: http://www.postgresqlconference.org/
United States PostgreSQL Association: http://www.postgresql.us/
Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate