多表连接update字段有关问题

多表连接update字段问题
sql server2005

udpate a set a.devsn=b.spec_val from tmp_dev a,tmp_devext b where b.devcode=a.devcode and b.item_spec_id='877064'

'.' 附近有语法错误。

------解决方案--------------------
update a set a.devsn=b.spec_val from tmp_dev a,tmp_devext b 
where b.devcode=a.devcode and b.item_spec_id='877064'

------解决方案--------------------

SQL code

update a set devsn=b.spec_val from tmp_dev a,tmp_devext b where b.devcode=a.devcode and b.item_spec_id='877064'