Re: returning composite types.

Franco Bruno Borghesi wrote:
> yes, i was trying to do something like that, but it breaks always in the same
> place, first I thought that it was because of the way I was assigning values
> to the fields of my row, but now I'm beginning to think that the reason is
> the way I pass the row to f2.
>
> Here is the error:
> franco=# SELECT f1();
> WARNING: Error occurred while executing PL/pgSQL function f1
> WARNING: line 5 at select into variables
> ERROR: Attribute "result" not found
>
> CREATE TYPE mytype AS (val1 INTEGER, val2 INTEGER, val3 INTEGER);
>
> CREATE OR REPLACE FUNCTION f1() RETURNS mytype AS '
> DECLARE
> result mytype%ROWTYPE;
> BEGIN
> result.val1:=1;
> SELECT val2, val3 INTO result.val2, result.val3 FROM f2(result);

It looks like plpgsql doesn't support composite type variables as
arguments to functions that are called from within a function. The error
is saying it cannot find an attribute named result -- that's because
there is no *attribute* called result, there is a rowtype variable.

I'm not sure right off what is involved in fixing this, but you can
always pass the individual attributes to f2:

CREATE TYPE mytype AS (val1 INTEGER, val2 INTEGER, val3 INTEGER);

CREATE OR REPLACE FUNCTION f2(int,int,int) RETURNS mytype AS '
DECLARE
arg1 ALIAS FOR $1;
arg2 ALIAS FOR $2;
arg3 ALIAS FOR $3;
newval2 int;
newval3 int;
result mytype%ROWTYPE;
BEGIN
newval2 := coalesce(arg2,2) * arg1;
newval3 := coalesce(arg3,3) * arg1;
SELECT INTO result.val1, result.val2, result.val3
arg1, newval2, newval3;
RETURN result;
END;
' LANGUAGE 'plpgsql';

CREATE OR REPLACE FUNCTION f1(int) RETURNS mytype AS '
DECLARE
result mytype%ROWTYPE;
BEGIN
result.val1:=$1;
SELECT INTO result.val2, result.val3 val2, val3
FROM f2(result.val1, result.val2, result.val3);
RETURN result;
END;
' LANGUAGE 'plpgsql';

regression=# select * from f1(2);
val1 | val2 | val3
------+------+------
2 | 4 | 6
(1 row)

HTH,

Joe