TORA-12154 and TNS-03505: unable to resolve name

Recently, after Oracle Developer Suite has been installed, you cannot log on to the system, enter an account logon error: ORA-12154: TNS: failed to parse the specified connection identifier.

Generally, this is because the configuration file does not contain the corresponding instance name. Then I enter C:/tnsping myoracle (My ora Instance name) to view tnsnames. ora and sqlnet. ora is configured correctly, the result is an error, prompt: TNS-03505: unable to resolve the name indicates that the configuration file is incorrect.

Then I checked the % Oracle_Home %/Db_1/NetWork/admin/TNSNAMES. ORA file and found that it contains the name of the instance I want to log on. I am trying the tnsping command and found the parameter file sqlnet. ora is not the sqlnet. ora, but sqlnet under the NetWork folder under the Oracle Developer Suite Directory. ora file, put tnsnames under the installation directory. copy the instance configuration content in ora. OK.

MYORACLE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP) (HOST = 127.0.0.1) (PORT = 1521 ))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = MYORACLE)
)
)

As to why the parameter file in the directory is changed to be used, we have not studied how to handle it. Write down the processing process first.