Nemůžete otestovat typ na základě specifikace funkce, ale můžete otestovat typ předávaných objektů pomocí IS OF( type )
operátor nebo SYS_TYPEID
funkce
:
Nastavení schématu Oracle 11g R2 :
CREATE type my_weird_type IS OBJECT
(
a NUMBER
) NOT FINAL
/
CREATE TYPE my_weird_subtype UNDER my_weird_type
(
b NUMBER
)
/
CREATE FUNCTION getType(
i_type my_weird_type
) RETURN VARCHAR2
IS
BEGIN
IF i_type IS OF( my_weird_subtype ) THEN
RETURN 'subtype';
ELSIF i_type IS OF( my_weird_type ) THEN
RETURN 'type';
ELSE
RETURN 'other';
END IF;
END;
/
CREATE FUNCTION getType2(
i_type my_weird_type
) RETURN VARCHAR2
IS
o_type USER_TYPES.TYPE_NAME%TYPE;
BEGIN
SELECT type_name
INTO o_type
FROM user_types
WHERE typeid = SYS_TYPEID( i_type );
RETURN o_type;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN NULL;
END;
/
create table test_my_weird_type(
value my_weird_type
)
/
INSERT INTO test_my_weird_type (value)
SELECT my_weird_type(1) FROM DUAL UNION ALL
SELECT my_weird_subtype(2,3) FROM DUAL UNION ALL
SELECT NULL FROM DUAL
/
Dotaz 1 :
SELECT t.value.a AS a,
TREAT( t.value AS my_weird_subtype ).b AS b,
getType( value ),
getType2( value )
FROM test_my_weird_type t
Výsledky :
| A | B | GETTYPE(VALUE) | GETTYPE2(VALUE) |
|--------|--------|----------------|------------------|
| 1 | (null) | type | MY_WEIRD_TYPE |
| 2 | 3 | subtype | MY_WEIRD_SUBTYPE |
| (null) | (null) | other | (null) |