PostgreSQL 11 - Procedures

Question

With the latest update of PostgreSQL supporting procedures. The official blog, quoted that \"As opposed to functions, procedures are not required to return a val

Answer 1

You can have INOUT parameters in a procedure.

You call a procedure with the CALL statement; if there are any INOUT parameters, the statement will return a result row just like SELECT.

Here is an example that uses a procedure that returns a refcursor:

CREATE PROCEDURE testproc(INOUT r refcursor) LANGUAGE plpgsql AS
$$BEGIN
   r := 'cur';
   OPEN r FOR VALUES (1), (42), (12321);
END;$$;

BEGIN;

CALL testproc(NULL);

  r  
-----
 cur
(1 row)

FETCH ALL FROM cur;

 column1 
---------
       1
      42
   12321
(3 rows)

COMMIT;

Answer 2

How about using the RAISE statement?

https://www.postgresql.org/docs/10/static/plpgsql-errors-and-messages.html