create or replace function caid_prids(integer) returns setof integer as '
DECLARE
  mycaid integer;
BEGIN
  mycaid := $1;
  LOOP
    RETURN NEXT mycaid;
    SELECT INTO mycaid prid from pr_categs where caid = mycaid;
    IF mycaid = 0 OR NOT FOUND THEN
       EXIT;
    END IF;
  END LOOP;
  RETURN;
END;
' LANGUAGE 'plpgsql';

create or replace function caid_main_prid(integer) returns integer as '
DECLARE
  mycaid,prcaid integer;
BEGIN
  mycaid := $1;
  LOOP
    SELECT INTO prcaid prid from pr_categs where caid = mycaid;
    IF prcaid = 0 OR NOT FOUND THEN
       RETURN mycaid;
    END IF;
    mycaid := prcaid;
  END LOOP;
  RETURN;
END;
' LANGUAGE 'plpgsql';