请问一个sql语句。谢谢

请教一个sql语句。多谢！
我在sql server中有一个如下语句：
Update H Set H.Num = H.Num + A.Num from HSAVE H,
(
  Select MF04, MF09, SUM(MF06) NUM from RKOMF
  WHERE MF01 = 'AA' AND MF02 = 'S001'
  Group by MF04, MF09
) A
Where H.H01 = A.MF04 AND H.H02 = A.MF09

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这个语句我在sql server中是可以正常执行的，可是到oracle中却通不过语法检查，说error第一行， 语句没有正常结束。
请问应该怎么写？

[解决办法]
try:
Update HSAVE H, 
( 
Select MF04, MF09, SUM(MF06) NUM from RKOMF 
WHERE MF01 = 'AA' AND MF02 = 'S001' 
Group by MF04, MF09 
) A Set H.Num = H.Num + A.Num from 
Where H.H01 = A.MF04 AND H.H02 = A.MF09
[解决办法]
oracel里的update只能单表，没有from
[解决办法]

SQL code

Update HSAVE H Set H.Num = (  Select  SUM(MF06)+h.num from RKOMF c  WHERE MF01 = 'AA' AND MF02 = 'S001'         and H.H01 = c.MF04 AND H.H02 = c.MF09     Group by c.MF04, c.MF09 )Where exists(  Select  1 from RKOMF c  WHERE MF01 = 'AA' AND MF02 = 'S001'         and H.H01 = c.MF04 AND H.H02 = c.MF09     )