You can achieve this with following 2 methods,
1. DataBase Connector module https://marketplace.mendix.com/link/component/2888
To connect Oracle database you need to download the Oracle JDBC driver https://www.oracle.com/in/database/technologies/appdev/jdbc-downloads.html and save that jar file inside the application’s userlib folder.
You can construct the SELECT queries and use the “Execute Query”
You need to configure, Jdbc URL, User name, Password, Query Statement, Result Object
Query Statement → Select query for the required table
Result Object → The Mendix Entity where you want to store your oracle table
2. Database replication module https://marketplace.mendix.com/link/component/160
Hope this helps!
Let me point you to the documentation:
“The recommended way is to migrate your existing on-premises non-PostgreSQL source database to a new on-premises PostgreSQL target database”
Basically you configure your Oracle DB as source DB in a) locally in Studio Pro (if you your Oracle DB isn’t too large for your local machine) or b) in the cloud using custom runtime settings.
The target DB must be empty and configured as active. On startup, the source DB will be copied to the target DB.