$query="SELECT b.transport_id, b.transport_type, b.transport_name FROM alert_transport_map AS a LEFT JOIN alert_transports AS b ON b.transport_id=a.transport_or_group_id WHERE a.target_type='single' AND a.rule_id=? UNION DISTINCT SELECT d.transport_id, d.transport_type, d.transport_name FROM alert_transport_map AS a LEFT JOIN alert_transport_groups AS b ON a.transport_or_group_id=b.transport_group_id LEFT JOIN transport_group_transport AS c ON b.transport_group_id=c.transport_group_id LEFT JOIN alert_transports AS d ON c.transport_id=d.transport_id WHERE a.target_type='group' AND a.rule_id=?";