associating mac addresses with usernames

[Stephen Vigus]

Hi all

First post to the list ;)

I want to use both mac authentication and username authentication. I
have both working fine separately from mysql, but I want associate
certain mac addresses to certain usernames and have it authenticate
with the username.
I thought I could use the following to authenticate mac addresses:
if("%{sql:SELECT radusergroup.username FROM authorized_macs LEFT JOIN
radusergroup ON ( authorized_macs.username = radusergroup.username )
WHERE authorized_macs.macaddr = ''%{User-Name}'}" > 0){
          ok
        }
        else{
          reject
        }

In mysql this query would display the username associated to the mac
(eg, user1 at realm1), although it seems freeradius does not like this.

Can anyone point me in the right direction so freeradius would think
its "user1 at realm1" authenticating when it receives the mac address?

thanks
Stephen