Need help in loop

osrn

i have the following query

$mysql="select keywords., count(), sitekeys.siteid from keywords left join sitekeys on keywords.id=sitekeys.keyid where sitekeys.siteid IS NULL group by keywords.id";
$res=$db->Execute($mysql);

if(!$res){
echo "Error ";
return;
}else{

count loop - Need help here

Example:

The result will be like this id count(*) siteid
10 1 NULL
11 1 NULL

I want to delete all the keywords which do not have any sites rather siteids associated with it.

I would appreciate if anyone can help----plsssssss - urgent

Thanks