update trainStudent set trainid=b.trainid
from trainStudent a,trainClass b
where a.cid=b.id and b.trainName='2008年第十批'
and a.trainid<>b.trainid
from trainStudent a,trainClass b
where a.cid=b.id and b.trainName='2008年第十批'
and a.trainid<>b.trainid