Oracle如何用关联查询结果更新一个表

[wushangjimo]

oracle 11g，情况是这样的，A（id，b_id，str） B（id，str）；现在通过要求是如果A.str=B.str，则把B.id写入A.b_id中。求高手指点一下~~~~

[莱昂纳多达芬奇]

update a set a.id = (select b.id from b where b.str = a.str) where exists(select * from b where a.str = b.str)

[ICE-word]

update A set A.id = (select b.id from b where b.str = A.str) where exists(select 1 from b where A.str = b.str)

[hello_cyx]

update a set a.id = (select b.id from b where b.str = a.str)