How to connect Oracle Database to Power BI

#1:

Make sure you have installed:

https://www.oracle.com/technetwork/database/windows/downloads/index-090165.html

#2:
Make sure your TNS Name file (tnsnames.ora) is correct
Test with Toad or other SQL Utility that uses the TNS NAME file
not SQL Developer (that does not use the tnsnames.ora file to Connect)
C:\app\client\your_windows_user_name\product\12.1.0\client_1\Network\Admin

#3:
In the Power BI Get Data Oracle database

In the box Server:
(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=service_name)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=your_service_name)))

Oracle database server format: Host:Port/SID

#4:
Use the database credentials to access your data

Helpful source: 

https://docs.microsoft.com/en-us/power-bi/connect-data/desktop-connect-oracle-database