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Date: Fri, 19 Aug 2005 22:44:30 -0700 (PDT)
From: Stephan Szabo <sszabo@megazone.bigpanda.com>
To: CSN <cool_screen_name90001@yahoo.com>
Cc: pgsql-docs@postgresql.org, pgsql-general@postgresql.org
Subject: Re: [GENERAL] Suggestion for Date/Time Functions Section
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On Fri, 19 Aug 2005, CSN wrote:

> Hi,
>
> I suggestion for the date/time functions in the docs:
> http://www.postgresql.org/docs/8.0/interactive/functions-datetime.html
>
> I was trying to figure out how to do:
> update table set next=now() + interval 'table.period
> seconds';
>
> I tried subqueries, the concat operator, and anything
> else I could think of until I rediscovered the page on
> the various ways to cast. Perhaps mix up the examples
> in the docs so other ways to do date arithmetic (and
> that allow expressions, fields, etc.) are obvious:
>
> date '2001-09-28' + cast((7+7)||' seconds' as
> interval);

I'd suggest something like
 date '2001-09-28' + (7+7) * interval '1 second';
instead of using text concatenation.