Hi,
let's say one has an user defined data type
CREATE TYPE foobar_t AS ( va varchar(25), vb varchar(4), vc varchar(20), ia integer, ib integer );
and a stored procedure in plgpsql (stripped and sample only):
CREATE OR REPLACE FUNCTION foobar(int, foobar_t, int, varchar) RETURNS INT AS'
DECLARE ia ALIAS FOR $1; fbt ALIAS FOR $2; ib ALIAS FOR $3;
vc ALIAS FOR $4;
BEGIN ... IF fbt IS NULL THEN RAISE NOTICE ''fbt IS NULL;''; ELSE RAISE
NOTICE''fbt IS NOT NULL... ''; IF fbt.va IS NULL THEN RAISE NOTICE ''fbt.va IS
NULL;''; ELSE RAISE NOTICE ''fbt.va = %'', fbt.va; END IF;
... END IF; ... RETURN 0;
END' LANGUAGE plpgsql;
If one does a
SELECT foobar(1, NULL, 2, 'end');
NOTICE: ia = 1
NOTICE: fbt IS NOT NULL...
NOTICE: fbt.va IS NULL;
NOTICE: fbt.vb IS NULL;
NOTICE: fbt.vc IS NULL;
NOTICE: fbt.ia IS NULL;
NOTICE: fbt.ib IS NULL;
NOTICE: ib = 2
NOTICE: vc = endfoobar
-------- 0
(1 row)
Note the second argument foobar_t is given as NULL
but $2 IS NOT NULL.
I cannot find anything about this in the docs but I asume
that the single NULL will implicitly set all attributes to NULL?
Is this correct or is it just a "works like that this time but may
change at any time in the future"?
--
Greetings
Bjoern A. Zeeb