SQLPLUS / AS SYSDBA failed to login ORA-12560 - oracle

Question

I am getting
ERROR:
ORA-12560: TNS:protocol adapter error
adapter error when attempt to login as SYSDBA. I did some research and find that firstly in Windows services there weren't any of the OracleJobSchedulerdb12gr1; OracleServicedb12gr1 .. e.t.c.
So I did add them and start:
C:\Windows\system32>oradim -new -sid db12gr1
So I start a listener as well:
C:\Windows\system32>lsnrctl start
And after that when I check the status I get:
C:\Windows\system32>lsnrctl status
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC1ipc)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
Services Summary...
Service "XE" has 1 instance(s).
Instance "XE", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
Not sure if the UNKNOWN is the problem I dropped every other SID_LIST_LISTENER from listener.ora and the LISTENER looks like this (in listener.ora) :
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
)
)
Also I have set my ORACLE_HOME to env vars correctly and added to Path the bin folder so I can access sqlplus. Defining ORACLE_SID (set ORACLE_SID=localhost) does not made any difference before I try to log as sysdba. Also I was able to start the services and start listener only from command prompt opened as administrator of course where still I can't sqlplus / as sysdba.
tnsnames.ora:
EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)
ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
)
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
)
)
XE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = XE)
)
)
I am really out of ideas. Anyone aware what might cost this ?
PS: OS: Windows 10 ; Oracle : 12c

Answer 1

You have to set your ORACLE_SID environement variable to the right value:
set ORACLE_SID=db12gr1
and make sure your instance service is correctly started.

Answer 2

lets do this:
1. Open Oracle Net Configuration Assistant
2. Select radio button option at Local Net Service Name Configuration, then click Next
3. Select radio button option at Reconfigure, then click next
4. Select net service name you want to reconfigure, either ORACLR_CONNECTION_DATA or ORCL, then click Next
5. input your Service Name, if your service name of installed oracle as ORCL, then write ORCL to the field, then click Next
6. select the protocol you want to use, for example, select TCP, then click Next
7. input hostname where your oracle database engine (service) installed, for example, installed on your desktop or notebook,
then fill as localhost, and fill your port number (select option Use the Standar port number of 1521) or if use other port, fill the port number
Then click next.
8. select Yes perform test,
if necessary, change user logon
then click next
9. if no configure another net service name, select No and then click next
10. Click Finish
you should download, extract and install the ODTwithODAC183.zip and BuildTools_Full.exe if you want use to connect on .net framework from MS Visual Studio