في مشكلة عندي في دخول برنامج SQL . اذا كتبت الاسم و كلمة السر صح او خطأ تظهر رسالة " خطأ في موفق البروتوكولORA - 12560 :TNS "

When starting server manager the following error is generated:

ORA-12560: TNS:protocol adapter error occurred

Cause:
Oracle classify this as a ‘generic protocol adapter error’. In my experience it indicates that Oracle client does not know what instance to connect to or what TNS alias to use

If running on the server (or workstation) that is running the database then check that the service name ‘OracleService<SID>’ ties up with the actual database SID. If the database SID is changed without recreating the service then this can lead to this error. To recreate the service:

oradimxx -delete -sid <old-sid>

oradimxx -new -sid <SID> -intpwd <internal-password> AUTO -pfile <full-init-ora-filename>