table_alias = $this->ensure_my_table(); // We need another subquery here to extract DISTINCT values $sql = "SELECT COUNT(usi.uid) FROM (SELECT DISTINCT(uid), ip_address FROM {user_stats_ips}) usi WHERE usi.ip_address = " . check_plain($this->table_alias) . ".ip_address"; $this->field_alias = $this->query->add_orderby(NULL, "(" . $sql . ")", $this->options['order'], $this->table_alias . '_' . $this->field); } }