Tables's data scrambled (randomized) for testing purposes

Question

Dear Oracle People,
I need to scramble (randomize) the date for testing purposes
How I can do that within Oracle
Source:
CODE          FIRST_NAME     LAST_NAME
1          FN_1               LN_1
2          FN_2               LN_2
3          FN_3               LN_3
Target after scrambling:
CODE          FIRST_NAME     LAST_NAME
1          FN_2               LN_3
2          FN_3               LN_1
3          FN_1               LN_2

Answer 1

Source table: t1
Target table: t2 (create table t2 as select * from t1)
Something like this would do:
DECLARE
rc NUMBER;
BEGIN
SELECT COUNT (*) INTO rc FROM t1;
FOR i IN (SELECT last_name FROM t1)
LOOP
UPDATE t2
SET last_name = i.last_name
WHERE code = ROUND (DBMS_RANDOM.VALUE (1, rc));
END LOOP;
END;