sql语句 如何在oracle中实现。。
update     a   set   a.hth= '33 ',a.htzh=   '00 ',a.rkrq   = '20070607 ',a.lrrq= '20070620 '  
from     a      
join     b      
on   a.id=b.id

------解决方案--------------------
这样呢

update a set a.hth= '33 ',a.htzh= '00 ',a.rkrq = '20070607 ',a.lrrq= '20070620 '
where (select count(*) from a,b where a.id=b.id)> 0
------解决方案--------------------
update a set a.hth= '33 ',a.htzh= '00 ',a.rkrq = '20070607 ',a.lrrq= '20070620 '
where a.id in (select id from b)