DAOExercise Architecture

Having implemented and written DAO code that accesses a MySQL
database, there need to be changes if that code is to access an
Oracle database. Though both databases use SQL, code that works
for one may be broken or have unexpected results in the other.
So the SQL code needs to be tested and rewritten as necessary.
The driver class needs to be rewritten with the proper commands
and authentication so as to get the right connection to the Oracle
database.

Whenever the database changes, the Java code has to be
rewritten to accommodate it. This is due to the hardcoding
of the SQL and driver information. The only way to not rewrite
all that is to throw it to a go-between which interacts with
the database and leaves the Java code handling objects only.