Re: DateDiff, IsNull?

On Tue, 14 Aug 2001, Bill wrote:

> Hello all,
>
>   I am a newbie to postgreSQL, is it possible to write a "DateDiff",
> "IsNull" function work same as the one in SQL Server and are there and
> sample out there? And is it possible to override the existing function and
> operator like "+" to become a concate?

I don't know what IsNull does but:

template1=> select coalesce(NULL, 'Hello');case
-------Hello
(1 row)

I do know what DateDiff does:

template1=> select '2001-08-14'::date - '6 weeks'::interval;       ?column?
------------------------2001-07-03 00:00:00-05
(1 row)

Overloading operators? *Please* tell me that this is impossible.

Alan Gutierrez