A quick tip, at the first login in DB you must to change the initial password but some tools cannot do this, for example dbeaver. But you can download sqlplus binaries from oracle web site and unzip it in some place to execute from command line.
I’ve downloaded the windows client instantclient-sqlplus-windows.x64-18.3.0.0.0dbru.zip
and executed the next command:
sqlplus.exe /nolog
To connect you can use one of these commands:
# TNS conn USER@TNS_ALIAS #SID (short like jdbc format) conn USER/PASS@host:port/SID # Service name CONNECT USER/PASS@'(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=sales.us.acme.com)))' # SID CONNECT USER/PASS@'(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=sales-server)(PORT=1521))(CONNECT_DATA=(SID=sales.us.acme.com)))'
Note the password is optional in command line but if you don’t set the client will ask for it.
Saludos