Oracle TNS names configuration. How to add TNSNAMES.ORA to toad?

What is TNSNames.ora file?

The TNSNames.ora file contains the specific information required to connect to the Oracle instance. By default, the TNSNames.ora file resides in {oracle home directory}\network\admin. For example, C:\Oracle_Client\network\admin.

If a TNSNames.ora file does not exist on the machine, you will need to create one in a text editor. We recommend storing the file in your My Documents folder as this is an easily identified folder and common on most machines. For example: C:\Users\gsbprogramming\Documents.  

Sample TNSNames.ora entry

[net_service_name]=
( DESCRIPTION=
  ( ADDRESS=[protocol_address_information] )
  ( CONNECT_DATA=
    ( SERVICE_NAME=[service_name] )
   )

)

You can get this entry by using TNSPING

Here XE is SID of oracle database. So we used TNSPING XE 

If SID is ORCL you will use:

TNSPING ORCL 

So TNSNAMES.ORA will have entry as:

MYTNS=

( DESCRIPTION=

    ( ADDRESS = ( PROTOCOL = TCP ) ( HOST = ErJatt) ( PORT = 1521 ))

    ( CONNECT_DATA = ( SERVER = DEDICATED ) ( SERVICE_NAME = XE ))

)

Here ErJatt is username . You can also use 127.0.0.1 here 

So write this in notepad 

Save this file as TNSNAMES.ORA in any directory (For example: C:\Oracle\TNS_ADMIN\)

As we have saved this file in C:\Oracle\TNS_ADMIN\ so we will create a TNS_ADMIN system environment variable with value C:\Oracle\TNS_ADMIN\

  Now tnsnames.ora will be automatically added to toad