Re: What happened to the is_ family of functions proposal? - Mailing list pgsql-hackers

On 09/20/2010 10:29 AM, Colin 't Hart wrote:
> Hi,
>
> Back in 2002 these were proposed, what happened to them?
>
> http://archives.postgresql.org/pgsql-sql/2002-09/msg00406.php


2002 is a looooooooong time ago.

>
>
> Also I note:
>
> colin@ruby:~/workspace/eyedb$ psql
> psql (8.4.4)
> Type "help" for help.
>
> colin=> select to_date('731332', 'YYMMDD');
>   to_date
> ------------
>  1974-02-01
> (1 row)
>
> colin=>
>
>
> The fact that this wraps would seem to me to make the implementation 
> of is_date() difficult.
>
>
>

I think to_date is the wrong gadget to use here. You should probably be 
using the date input routine and trapping any data exception. e.g.:
    test_date := date_in(textout(some_text));

In plpgsql you'd put that inside a begin/exception/end block that traps 
SQLSTATE '22000' which is the class covering data exceptions.

cheers

andrew