Completely solve the annoying ORA-12560: TNS: protocol adapter error

Encountered a frustrating "ORA-12560: TNS: protocol adapter error" error when connecting to the database? A web search may not provide a clear solution, this guide will provide a comprehensive approach to solving the problem.

Step-by-step troubleshooting:

1. Verify Oracle database service status

• Access the Windows machine hosting the Oracle database server.
• Enter "services.msc" in the run dialog box to start the service panel.
• Find "OracleService " (for example, OracleServiceORCL) and check if it is running. If not, click Start to start the database service.

2. Test TNS configuration

• Open command prompt.
• Run the following command:

tnsping 

• Replace with the entry found in the tnsnames.ora file.

illustrate:

This command verifies that the TNS configuration is correct and that the database listener is listening for connections. If the command is successful, it means the TNS entry is valid and the database can be accessed. If the test fails, you may need to check your network settings or adjust your TNS configuration accordingly.

By systematically following these steps, you can accurately identify the cause of the ORA-12560 error and implement the necessary corrective actions to restore seamless database login access.