dbms_result_cache.INVALIDATE (USER, 'BETWNSTR');

END;

CREATE OR REPLACE FUNCTION betwnstr (

string_in IN VARCHAR2

, start_in IN INTEGER

, end_in IN INTEGER

)

RETURN VARCHAR2 RESULT_CACHE

IS

DBMS_OUTPUT.put_line ( 'betwnstr for '

|| string_in

|| '-'

|| start_in

|| '-'

|| end_in

);

RETURN (SUBSTR (string_in, start_in, end_in - start_in + 1));

END;

DECLARE

l_string employees.last_name%TYPE;

DBMS_RESULT_CACHE.INVALIDATE (USER, 'BETWNSTR');

FOR rec IN (SELECT *

FROM employees

WHERE ROWNUM < 11)

LOOP

l_string :=

CASE MOD (rec.employee_id, 2)

WHEN 0

THEN betwnstr (rec.last_name, 1, 5)

ELSE betwnstr ('FEUERSTEIN', 1, 5)

END;

END LOOP;

END;