On 2014-04-02 12:27:30 -0400, Tom Lane wrote:
> David Johnston <polobo@yahoo.com> writes:
> > Does something like:
> > SELECT ($1 + $2)::$1%TYPE
> > exist where you can explicitly cast to the type of the input argument?
>
> I don't think SQL-language functions have such a notation, but it's
> possible in plpgsql, if memory serves.
Sometimes you can play nasty tricks using COALESCE() to force a cast
like that.
E.g. SELECT COALESCE(NULLIF($1, $1), $1 + $2);
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services