一个随机字符串的例子

dbms_random.string(opt IN CHAR, len IN NUMBER)
RETURN VARCHAR2;

opt seed values:
'a','A'  alpha characters only (mixed case)
'l','L'  lower case alpha characters only
'p','P'  any printable characters
'u','U'  upper case alpha characters only
'x','X'  any alpha-numeric characters (upper)

例子：
CREATE TABLE random_strings AS
SELECT rownum RNUM,
dbms_random.string('A', 12) RNDMSTR
FROM all_objects
WHERE rownum <= 200;

col rndmstr format a20

SELECT * FROM random_strings;