sql语句 判断记录是否存在的问题

 公交线路主表way  线路id(wayid)  线路名称(wayname)  备注 
                       1              100      
                    2              200  
                    3              300 
                    4              500 
 线路明细表waydetail    公交站id(waydetail )  站名(waydetailname)  线路id(wayid)  顺序(SEQ)  备注 
                              20                A01                      1            1 
                          21                A02                      1            2 
                          22                A03                      1            3 
                          23                A04                      1            4 
                          24                B01                      2            1 
                          25                B02                      2            2 
                          26                B03                      2            3 
                          27                B04                      2            4 
                          28                B05                      2            5 现在已经知道 站名一（如A01） ，站名二(A02) ，线路id ，
判断 线路id同时存在站名一和站名二 目前自己也写出了sql ：
                      select *  from (
                      select  A01  from dual
                   union
                   select  A01  from dual )
                    intersect 
                   select  waydetailname  from waydetail  where   wayid =  线路id ,
如果查询有记录  表示这样线路存在。另外还有方式     select  A.wayid  from waydetailname  a ,waydetailname   b
               where A.wayid =  线路id and
                     A.wayid  =B.wayid  and A.waydetailname ='A01'  and B.waydetailname ='A02'  
  
目前用后面的一种，
不知道还有其他更为简单的方法吗