Re: How to implement GOMONTH function

Andrus ha escrito:
> I need to create function GOMONTH which returns date by given number of
> month before or forward using sql or pgsql in 8.1+
> For example,
> GOMONTH( DATE '20070513', 1 )  should return date '20070613'
> GOMONTH( DATE '20070513', -2 )  should return date '20070313'
>
> I tried
>
> CREATE OR REPLACE FUNCTION public.gomonth(date, integer,
>         out date) IMMUTABLE AS
> $_$
> SELECT $1 + $2'months';
> $_$ language sql
>
> but got error
>
> ERROR: syntax error at or near "'months'"
>
> How to implement this ?
>
> Andrus.

CREATE OR REPLACE FUNCTION
PUBLIC.GOMONTH(DATE, INTEGER, OUT DATE) IMMUTABLE AS
$_$
SELECT ($1 + ($2 || 'MONTHS')::INTERVAL)::DATE;
$_$ LANGUAGE SQL