ERROR: ORA-12154: TNS:could not resolve the connect identifier specified (First time installation)

Question

Im trying out oracle database 21c for learning purposes. This is the first time installation of oracle database. Im getting this error while logging in:- ERROR: ORA-12154: TNS:could not resolve the connect identifier specified.

I was expecting for a successful login and a query interface. I have no idea what to do with this.

Answer 1

https://www.databasestar.com/ora-12154/ I followed this solution and this works. If the link doesn't work: Most likely ur system might be missing ORACLE_HOME env variable:

• create a env variable ORACLE_HOME with the admin folder of ur DB installation. Like this:
• ORACLE_HOME -> D:\OracleDB\homes\OraDB21Home1\network\admin