Oracle 12c database cannot log in as a local user I met a problem from Oracle 12C Database, when I try to login to the user account with commandconn test/test, I got prompt of "invalid username/password, logon denied". 
when I use conn test/test@PDBORCL, I got "Could not resolve the connect identifier specified"
Can anyone please help me out? I really appreciate!!
Strangely, changing my service name to UPPERCASE has helped!


Changed case of service name to UPPERCASE in tnsnames.ora for pluggable database ("ORCLPDB" in my case).
Follow below commands:



Note: service name in uppercase while connecting ex SCOTT/TIGER@ORCLPDB

Not sure why this has worked for me !!