Per accedere ai super metodi, prova l'invocazione generale o l'espressione generalizzata. Ad esempio, utilizzando un supertipo persona e un sottotipo studente:
CREATE OR REPLACE TYPE person_typ AS OBJECT (
idno number,
name varchar2(30),
phone varchar2(20),
MAP MEMBER FUNCTION get_idno RETURN NUMBER,
MEMBER FUNCTION show RETURN VARCHAR2)
NOT FINAL;
CREATE OR REPLACE TYPE BODY person_typ AS
MAP MEMBER FUNCTION get_idno RETURN NUMBER IS
BEGIN
RETURN idno;
END;
MEMBER FUNCTION show RETURN VARCHAR2 IS
BEGIN
-- function that can be overriden by subtypes MEMBER FUNCTION show RETURN VARCHAR2 IS BEGIN
RETURN 'Id: ' || TO_CHAR(idno) || ', Name: ' || name;
END;
END;
CREATE TYPE student_typ UNDER person_typ (
dept_id NUMBER,
major VARCHAR2(30),
OVERRIDING MEMBER FUNCTION show RETURN VARCHAR2)
NOT FINAL;
CREATE TYPE BODY student_typ AS
OVERRIDING MEMBER FUNCTION show RETURN VARCHAR2 IS
BEGIN
RETURN (self AS person_typ).show || ' -- Major: ' || major ;
END;
END;
-- Using Generalized Invocation
DECLARE
myvar student_typ := student_typ(100, 'Sam', '6505556666', 100, 'Math');
name VARCHAR2(100);
BEGIN
name := (myvar AS person_typ).show; --Generalized invocation
END;
-- Using Generalized Expression
DECLARE
myvar2 student_typ := student_typ(101, 'Sam', '6505556666', 100, 'Math');
name2 VARCHAR2(100);
BEGIN
name2 := person_typ.show((myvar2 AS person_typ)); -- Generalized expression
END;
MODIFICA:
Se sei su 10g, dovrai organizzare le funzioni in modo leggermente diverso, ma la stessa funzionalità del bambino per chiamare il metodo super:
CREATE TYPE BODY person_typ AS
MAP MEMBER FUNCTION get_idno RETURN NUMBER IS
BEGIN
RETURN idno;
END;
-- static function that can be called by subtypes
STATIC FUNCTION show_super (person_obj in person_typ) RETURN VARCHAR2 IS
BEGIN
RETURN 'Id: ' || TO_CHAR(person_obj.idno) || ', Name: ' || person_obj.name;
END;
-- function that can be overriden by subtypes
MEMBER FUNCTION show RETURN VARCHAR2 IS
BEGIN
RETURN person_typ.show_super ( SELF );
END;
END;
CREATE TYPE student_typ UNDER person_typ (
dept_id NUMBER,
major VARCHAR2(30),
OVERRIDING MEMBER FUNCTION show RETURN VARCHAR2)
NOT FINAL;
CREATE TYPE BODY student_typ AS
OVERRIDING MEMBER FUNCTION show RETURN VARCHAR2 IS
BEGIN
RETURN person_typ.show_super ( SELF ) || ' -- Major: ' || major ;
END;
END;
Ora chiamerai show_super() da student per il metodo person, o semplicemente show() per il metodo student.
Dai documenti, spero che ti aiuti.