Re: [GENERAL] A real currency type

On Tue, Mar 21, 2006 at 08:49:18AM -0500, Bruce Momjian wrote:
>
> This looks very interesting. Should we add it to the core distribution?

Excellent question. As yet I have received very little feedback on it,
though it does work as advertised. I have had some people complain that
while they'd like to use it (especially the timestamp-that-remembers-
the-timezone), they don't like the idea of an external module.

I suppose the are a few technical issues that could be raised, like the
fact that it searches user tables during the parse phase, but this is a
generic problem with non-immutable type input functions.

I'd like it to be considered for inclusion. If the interest is there I
can make any changes people suggest.

Have a nice day,

>
> ---------------------------------------------------------------------------
>
> Martijn van Oosterhout wrote:
> -- Start of PGP signed section.
> > For a while I've been wondering about making a type that was really a
> > shell around a base type that tagged the type in some way. For example,
> > associating a currency with a numeric and complaining about additions
> > between mismatches.
> >
> > Well, I did it and it's available here:
> > http://svana.org/kleptog/pgsql/taggedtypes.html
> >
> > Below some examples of it in action. Yes, that's a timestamp that
> > remembers the timezone. Neat huh?
> >
> > Tested on 7.4 and a recent 8.1devel so it should work for most people.
> > Installation reports welcome. Note, this is beta software, don't run it
> > on your production server. Thanks.
> >
> > Have a nice day,
> >
> >
> > test=# select '5.6 USD'::currency + '4.5 USD'::currency;;
> > ?column?
> > -----------
> > 10.10 USD
> > (1 row)
> >
> > test=# select '5.6 USD'::currency + '4.5 AUD'::currency;;
> > ERROR: Using operator +(currency,currency) with incompatable tags (USD,AUD)
> > test=# select c1, print_currency(c1) from c;
> > c1 | print_currency
> > ------------+----------------
> > 232.44 USD | US$ 232.44
> > 21.20 EUR | ? 21.20
> > -13.44 AUD | AU$ -13.44
> > 0.01 USD | US$ 0.01
> > 14.00 AUD | AU$ 14.00
> > (5 rows)
> >
> > test=# select 5.4*c1 from c where tag(c1) = 'AUD';
> > ?column?
> > ------------
> > -72.58 AUD
> > 75.60 AUD
> > (2 rows)
> >
> > test=# select t, "timestamp"(t), date_part('hour',t) from c;
> > t | timestamp | date_part
> > -----------------------------------------+---------------------+-----------
> > 2005-08-14 02:00:00+02 Europe/Amsterdam | 2005-08-14 02:00:00 | 2
> > 2005-08-14 02:00:00+02 Australia/Sydney | 2005-08-14 10:00:00 | 10
> > 2005-08-14 02:00:00+02 Asia/Hong_Kong | 2005-08-14 08:00:00 | 8
> > 2005-08-14 02:00:00+02 America/New_York | 2005-08-13 20:00:00 | 20
> > 2005-08-14 02:00:00+02 Asia/Kuwait | 2005-08-14 03:00:00 | 3
> > (5 rows)
> >
> > --
> > Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> > > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> > > tool for doing 5% of the work and then sitting around waiting for someone
> > > else to do the other 95% so you can sue them.
> -- End of PGP section, PGP failed!
>
> --
> Bruce Momjian http://candle.pha.pa.us
> SRA OSS, Inc. http://www.sraoss.com
>
> + If your life is a hard drive, Christ can be your backup. +
>
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> TIP 5: don't forget to increase your free space map settings

--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.