高手帮忙，小弟急求SQL写法。

Question

Workorderstep2表结构。                      
                
NAME ISNULL TYPE                                    
WORKORDER_GUID Y CHAR(36)
WORKORDERSTEP_GUID N CHAR(36)
OLDHANDLEBY_ID Y CHAR(6)
OLDHANDLEGROUP_ID Y CHAR(6)
HANDLEBY_ID Y CHAR(6)
HANDLEGROUP_ID Y CHAR(6)
WORKORDERSTEPSTATUS Y CHAR(6)
COMMENTS Y VARCHAR2(1024)
handleby_id     Y       VARCHAR2(6)
MODIFIEDDATE Y DATE(7)
WORKORDERSTEPID Y CHAR(6)
STEPEXPIRED Y DATE(7)workorder2表结构：
NAME    ISNULL  TYPE
WORKORDER_GUID  N       CHAR(36)
CURSTEPCOMMENTS Y       VARCHAR2(3000)
CREATEDBY       Y       CHAR(6)
CREATEDDATE     Y       DATE(7)
MODIFIEDBY      Y       CHAR(6)
MODIFIEDDATE    Y       DATE(7)
其中workorder2和workorderstep2的两个表的关系是一对多的关系，即workorder2.workorder_guid在workorderstep2表的workorder_guid可以出现多次。但是workorderstep2表的workorderstep_guid是唯一的。而且workorder2表的workorder_guid也是唯一的。现在想编写一条SQL语句：即想得到主表的workorder_guid在workorderstep2表的最近一次修改时间的COMMENTS字段的值和主表的handleby_id,CURSTEPCOMMENTS 的字段的值？请问这样的一对多的SQL语句该怎么写？

Answer 1

select a.handleby_id,a.CURSTEPCOMMENTS,
       max(b.COMMENTS) keep(dense_rank last order by MODIFIEDDATE) comments
from   workorder2 a, Workorderstep2 b
where  a.WORKORDER_GUID=b.WORKORDER_GUID
group  by a.handleby_id,a.CURSTEPCOMMENTS

Answer 2

keep(dense_rank last order by b.MODIFIEDDATE) 

Answer 3

SELECT A.workorder_guid,A.handleby_id,A.CURSTEPCOMMENTS,B.COMMENTS
FROM workorder2 A,
Workorderstep2 B,
(SELECT workorder_guid,MAX(MODIFIEDDATE) MODIFIEDDATE 
FROM Workorderstep2 GROUP BY workorder_guid) C
WHERE A.workorder_guid=B.workorder_guid AND A.workorder_guid=C.workorder_guid 
AND B.MODIFIEDDATE=C.MODIFIEDDATE