$p->selectAdd();
$p->selectAdd("id, ((@row_number := CASE WHEN @row_number IS NULL THEN 0 ELSE @row_number END +1) % {$num_servers}) as rn");
- $kv = $p->fetchAll('id,rn');
+ $kv = $p->fetchAll('id','rn');
foreach($kv as $id => $r) {
$up[ $ids[$r] ][] = $id;
}