RE: [SQL] null values to be replaced by a default value

I would really like to be able to do the same thing!!!  The following
function seems to work okay:
CREATE FUNCTION nz (int4) RETURNS int4 AS '        BEGIN                IF ($1 IS NULL) THEN                 RETURN 0;                 ELSE                 RETURN $1;                END IF;        END;        ' LANGUAGE 'plpgsql';

-----Original Message-----From:	Nuchanard Chiannilkulchai [SMTP:nuch@valigene.com]Sent:	Tuesday, April 20, 1999 9:32 AMTo:	pgsql-sql@postgreSQL.orgSubject:	[SQL] null values to be replaced by a default value
Hi,
    To return one value not null, i've created a function :
CREATE FUNCTION isnull (int4,int4 ) RETURNS int4 AS '        BEGIN                IF ($1 IS NULL) THEN                 RETURN $2;                 ELSE                 RETURN $1;                END IF;        END;        ' LANGUAGE 'plpgsql';
select isnull(my_int,0) as number, sample_id from my_table;
but I gotnumber  |sample_id------+---------              |       13              |       15
What should I do to have '0' in the column 'number' instead of NULL
?Thanks,
    nuch