----- Original Message -----
From: "Héctor Iturre" <hhiturre@yahoo.com.ar>
To: <pgsql-sql@postgresql.org>
Sent: Monday, December 09, 2002 11:30 AM
Subject: [SQL] ISNULL FUNCTION
> HI,
> HERE IS AN ALTERNATIVE TO USE THE SQL SERVER
> ISNULL() FUNCTION
>
>
> select case when FIELD_NAME isnull then 'EXPRESION'
> else FIELD_NAME end
> from calfiscal
> where impuesto = 1
>
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> http://www.postgresql.org/users-lounge/docs/faq.html
Segue um exemplo que funciona satisfatoriamente.
Recrie esta função alterando os parametros (text, text e RETURNS text) para
os tipos que lhe for necessario.
CREATE FUNCTION isnull(text, text) RETURNS text AS 'SELECT (CASE (SELECT $1
is null) WHEN true THEN $2 ELSE $1 END) AS RESULT' LANGUAGE 'sql';
COMMENT ON FUNCTION isnull(text, text) IS 'Retorna o 2º arg se o 1º for
nulo';