Message-ID: <3F3A3523.4261096@rodos.fzk.de>
Date: Wed, 13 Aug 2003 14:54:59 +0200
From: Christoph Haller <ch@rodos.fzk.de>
MIME-Version: 1.0
To: pgsql-sql@postgresql.org, luiz@klais.com.br
Subject: Re: Insert a description while creating a table
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> > I want to insert descriptions at the columns of my tables but
without
> > using the command COMMENT ON. I want to do it together with the
table
> > creation. Is that possible?
> >
> > I wanna do something like this:
> >
> > create table test (
> >     id serial 'Descripitions about ID',
> >     name varchar(50) 'Descriptions about NAME'
> > );
>
> Probably not going to happen in the backend.
>
> However, you should be able to accomplish that with a little bit of
Perl
> to pre-process the SQL.
>
That perl script comes to my mind too.
The reason why Luiz doesn't like it, may be because you can't
see these descriptions within psql using \dd test

I did
the create table, then
COMMENT ON COLUMN test.id is 'Descripitions about ID';
COMMENT ON COLUMN test.name is 'Descriptions about NAME';
\dd test shows

         Object descriptions
 Schema | Name | Object | Description
--------+------+--------+-------------
(0 rows)

This is odd. OK, I know the doc says
\dd [ pattern ]

    Shows the descriptions of objects matching the pattern, or of all
visible objects if no argument is given. But in either case,
    only objects that have a description are listed. ("Object" covers
aggregates, functions, operators, types, relations (tables, views,
    indexes, sequences, large objects), rules, and triggers.) For
example:

Nothing about columns.
But what is the purpose of comments on columns if you can only get them
via
select * from pg_description where
 objoid = (select typrelid from pg_type where typname='test')
 order by objsubid ;
 objoid | classoid | objsubid |       description
--------+----------+----------+-------------------------
  17326 |     1259 |        1 | Descripitions about ID
  17326 |     1259 |        2 | Descriptions about NAME
(2 rows)

which you'll have to find out on your own.

Regards, Christoph