Try this query (replace select objects as required)
select Caption,SysName,MachineType,IP_Address,LastBoot,SystemUpTime,CPULoad,MemoryUsed,City, round((TotalMemory/1024/1024/1024),0) AS 'RAM in GB
from nodes (NOLOCK)
where DeviceRole = 'workstation' and ObjectSubType = 'SNMP'
and round((TotalMemory/1024/1024/1024),0) <= 4096