Re: NULL values and string

Richard Huxton wrote:

> Sergey Karin wrote:
>
>> Are there any abilities to represent NULL values as string?
>
>
> Null isn't a real value. Try not to think of it as a value.
>
That being said, and with due credit elsewhere (http://www.varlena.com/varlena/GeneralBits/84.php), what I do is

CREATE OR REPLACE FUNCTION public.textcat_null(text, text)
RETURNS text AS
'SELECT textcat(COALESCE($1, ''''), COALESCE($2, ''''));'
LANGUAGE sql' VOLATILE;

CREATE OPERATOR public.||+(
PROCEDURE = "public.textcat_null",
LEFTARG = text,
RIGHTARG = text);

This goes against proper form, considering what NULL is designed for, but it sure is convenient.

Regards,
Berend Tober