Thread

Re: [HACKERS] date/time problem in v6.5.3 and 7.0.0 ...

Jose Soares <jose@sferacarta.com> — 2000-01-18T14:10:58Z

The Hermit Hacker wrote:

> I can add days to now(), but not subtract?
>
> =====================================
>
> template1=> select now() + '30 days';
>            ?column?
> ------------------------------
>  Sun Feb 13 22:00:33 2000 AST
> (1 row)
>
> template1=> select now() - '30 days';
> ERROR:  Unable to identify an operator '-' for types 'timestamp' and 'unknown'
>         You will have to retype this query using an explicit cast
> template1=> select version();
>                                version
> ---------------------------------------------------------------------
>  PostgreSQL 7.0.0 on i386-unknown-freebsd4.0, compiled by gcc 2.95.2
> (1 row)
>
> Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
> Systems Administrator @ hub.org
> primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org
>
> ************

Try using standard names (TIMESTAMP instead of now() and INTERVA) as in:

hygea=> select current_timestamp + interval '30 day';
?column?
--------------------------
17/02/2000 16:00:28.00 CET
(1 row)

hygea=>  select current_timestamp - interval '30 day';
?column?
--------------------------
19/12/1999 16:00:44.00 CET
(1 row)

hygea=> select now() - '30 day';
ERROR:  Unable to identify an operator '-' for types 'timestamp' and 'unknown'
        You will have to retype this query using an explicit cast

José