Oracle生成MD5

create or replace function MD5_Digest (
vin_string IN VARCHAR2
) RETURN VARCHAR2 IS
--
-- Return an MD5 hash of the input string.
--
BEGIN
RETURN UPPER(Dbms_Obfuscation_Toolkit.Md5 ( input => utl_raw.cast_to_raw(vin_string)
            ));
END MD5_Digest;

http://www.blogjava.net/waterye/archive/2005/08/26/11253.aspx