联合查询问题

String sql="SELECT a.member_id,a.market_name,a.`name`,a.addr,a.mobile,a.tel,m.mobile as mobile1,admin.realname FROM es_member m,es_member_address a,es_member_attribute ar,es_adminuser admin WHERE m.member_id=a.member_id AND m.attribute_id=ar.id AND ar.work_id=admin.userid AND m.regtime<=? and m.regtime>=?";
        
        List<Map> map=this.baseDaoSupport.queryForList(sql, starttime,endtime);
        if(map.size()>0){
            return map;
        }else{
            return null;
        }