ORA-12560: TNS: protocol adapter error issue

ORA-12560: TNS: Problems with protocol adapter errors cause ORA-12560: TNS: Problems with protocol adapter errors there are three reasons: 1. the listening service didn't start up. On the windows platform, perform the following operations: start --- program --- management tools --- Service, open the service panel, and start the oraclehome92TNSlistener service. Www.2cto.com 2. database instance does not start. On windows, perform the following operations: start --- program --- management tools --- Service, open the service panel, start oracleserviceXXXX, and XXXX is your database SID. 3. Registry issues. Regedit, and enter HKEY_LOCAL_MACHINE \ SOFTWARE \ ORACLE \ HOME0 to set the environment variable ORACLE_SID to XXXX. XXXX is your database SID. or right-click my computer and choose "property"> "advanced"> "environment variable"> "system variable"> "new". The variable name is oracle_sid, the variable value is XXXX, and XXXX is your database SID. Or, before entering sqlplus, enter set oracle_sid = XXXX under command line, and XXXX is your database SID. After the above steps, you can solve the problem. Author: yjpfj1203