update t1 set t1.value=t2.value from tbl t1 inner join tbl2 t2 on t1.name=t2.name and t2.type='A' where t1.type='B' (untested! 😉 )
update t1 set t1.value=t2.value from tbl t1 inner join tbl2 t2 on t1.name=t2.name and t2.type='A' where t1.type='B' (untested! 😉 )