Adding site filtering

I have this query report that is working fine but now that many more computer come in I need to filter that report by site. How to I do that?

 

select si.workstationname 'WORKSTATION_NAME', sls.softwarename 'SOFTWARE_NAME',aaau.First_name 'NAME' from systeminfo si
left join softwareinfo sl on si.workstationid=sl.workstationid left join softwarelist sls on sls.softwareid=sl.softwareid
left join resourceowner ro on si.workstationid=ro.resourceid left join sduser sdu on sdu.userid=ro.userid
left join aaauser aaau on aaau.user_id=sdu.userid where sls.softwarename like '%SQL%' order by 1

 

Thanks for your help.

 

Dominique