C++ ODB Existing Database

I have created a program in C++ that parses through an existing text file for pertinent information which needs to be stored in a database. For this example, I would need to store in an oracle table, however I wanted to make the program scalable for different databases.

After some research I stumbled upon ORM/ODB by Code Synthesis. However, there doesn't seem to be much documentation on working with an existing database. Some of the examples for existing schemas drop and alter tables, which I do not want to do. How would I go about just adding to an existing table in say Oracle for example without dropping or altering tables.

This is the demo i'm referring to: ODB Custom Schema

Is there an easier way to create a database class with basic functionality (update, insert, drop/delete) and connect to the database?