How to enter users in sql?

[Just E. Mail]

I have successfully setup a freeRADIUS server with PostgreSQL backend 
(separate) server. When I start freeRADIUS in test mode 'radiusd -X', it 
connects to the sql server and there is no error. I have two general 
questions:

1. I need to add one or two test UID & PW in the SQL database. Is there 
a GUI application available to accomplish that or I have to do it 
manually entering the data?

2. When the freeRADIUS server is live (on-line) how does user 
authentication data gets added into the database? In MD5, LINUX has an 
application to add USER Name & Group (created automatically) which both 
email program (such as Postfix) and freeRADIUS authenticate against. How 
is it done in PostgreSQL?

I have tried to post this question as clearly as I can. Please ask and 
clarification!

Jennifer K.