mysql left联接查询实现多表查询

select w.*,lt_name,lpt_name,road_name,area_name from warning w"
                            + " left join lightnode on (w_lightnodeid=lt_id)"
                            + " left join lamppost on (lt_lamppostid=lpt_id) "
                            + " left join roadnode on (road_id = lpt_roadId)"
                            + " left join areanode on (area_id=road_areaId)");