How to confirm the oracle client in the service_name TNSNAMES

We install oracle client, or PLSQL develop when the need to modify TNSNAME TNS configuration parameters in the database you want to connect in the installation directory of the oracle. That can be configured by using the command line command to test tnsping, but sometimes tnsping pass on does not mean that the database can be connected, but also to determine TNSNAME inside SERVICE_NAME is correct, this SERVICE_NAME can query by sql command, the query is select instance_name from v $ instance