How to set tnsnames.ora file to PLSQL Developer

If you install and use PLSQL Developer you maybe have a file called "tnsnames.ora".

Commonly tnsnames.ora was create by Oracle configuration tools

This file contains valuable information that is use to connect to your Oracle database, whne you have some domains and endpoints(ip)

If your PLSQL Developer dont recognize or find it you can fix easy.

Only that you have to do is set and enviroment variable called "TNS_ADMIN"  like that:

TNS_ADMIN=C:\path\to\folder\that\contains\file

Restart your PLSQL Developer and that's OK