if you want to code, you can go with Ayus, also heard MD5 is not that good for password protection, try using sha digests.
I found some inbuilt functionality with mysql (always easier and less error prone to use inbuilt api)
src:http://mysqldatabaseadministration.blogspot.com/2006/08/storing-passwords-in-mysql.html

You can apply SHA1 algorithm to a password string:

mysql>  SELECT SHA1('mysecretpassword');
+------------------------------------------+
| SHA1('mysecretpassword')                 |
+------------------------------------------+
| 08cd923367890009657eab812753379bdb321eeb |
+------------------------------------------+
1 row in set (0.00 sec)

Since SHA is an alias for SHA1, it produces the same result

mysql>  SELECT SHA('mysecretpassword');
+------------------------------------------+
| SHA('mysecretpassword')                  |
+------------------------------------------+
| 08cd923367890009657eab812753379bdb321eeb |
+------------------------------------------+
1 row in set (0.00 sec)

To store passwords encrypted with SHA1, we need to be able to store 40 characters.

mysql> SELECT CHARACTER_LENGTH(SHA1('mysecretpasswordsssssss'));
+---------------------------------------------------+
| CHARACTER_LENGTH(SHA1('mysecretpassword')) |
+---------------------------------------------------+
|                                                40 |
+---------------------------------------------------+
1 row in set (0.00 sec)

On the other hand, to store passwords encrypted with MD5, we need the column to be able to hold 32 characters.

mysql>  SELECT MD5('secretpassword');
+----------------------------------+
| MD5('secretpassword')            |
+----------------------------------+
| 2034f6e32958647fdff75d265b455ebf |
+----------------------------------+
1 row in set (0.00 sec)

mysql>  SELECT CHARACTER_LENGTH(MD5('secretpassword'));
+-----------------------------------------+
| CHARACTER_LENGTH(MD5('secretpassword')) |
+-----------------------------------------+
|                                      32 |
+-----------------------------------------+
1 row in set (0.00 sec)


Didnt find much on oracle except for following 
http://psoug.org/reference/dbms_crypto.html

Good luck